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  1. #1

    well shoot! ZF6 goes kablooey!

    just had to express my surprise and frustration... visited family near Fort Worth for the holiday, drove the truck down and back via 287. Its our preferred route and we can generally knock the drive out in about 10 hours, but to make good time you best be prepared to execute some fairly aggressive passing maneuvers on the single lane stretches in CO.

    Just south of Limon on the way back I dropped the hammer in a passing lane to get past three trucks and a couple of cars that were doing 50. At about 42psi and 3,000rpm it popped out of 6th gear with a loud bang. Startled the heck out of me and the dog to say the least, but I popped it back into gear and kept going like nothing happened.

    About 5 miles after getting onto 70 I leaned lightly into the throttle to get around a truck and at about 12psi it popped out again with a moderate pop sound and that was that... no more overdrive...

    given that the truck has been tuned well above stock power since the day it was new and is now sporting 306k miles and WAY higher power I shouldn't be too shocked anytime an original part fails.

    But still, she has very bad timing with this. Winter sports and the holiday roadtrips, and I was about to launch into a major project to add a BW EFR turbocharger onto my wifes Ford Escape. The Mrs. is not too thrilled to have her project put off again. grrrrrrr...

    I've rebuilt a couple of manuals transmissions, and though this one is very large, it looks honestly more friendly to work than most. I'm hopeful that I've just lunched the OD synchro and if so rebuilding the countershaft assembly might be a couple hundred buck job and fairly straightforward. My real problem with this strategy will be pulling it all apart, inspecting and then waiting for parts resulting in a couple of weeks of downtime.

    To my surprise, I checked out car-parts.com and a junkyard ZF6 goes for close to $2g! I wouldn't mind just tossing in a 200k miles trans but not at that price. Midwest trans sells dyno tested rebuilds with a generous warranty for about 2.5k! I might consider going that route as this would obviously put any question of trans reliability off into the way distant future.

    I might also consider not kicking it into kill mode for passing anymore....

    oh well... fun stuff. beats having a truck payment i suppose. ....
    1950 CJ3a - Wilma
    1999 F350 PSD - Betty

  2. #2
    Maybe a transmission from a medium-duty truck? Nothing particular comes to mind, but it might be stronger....

    And yes, tunes can be hard on manuals as well as autos.
    "Your 2007 X3 is at home on all paved and unpaved roads. You can operate your vehicle on uphill and downhill gradients with a maximum slope of 50%. The permitted side tilt is 32%. While driving watch carefully for obstacles such as rocks or holes. Try to avoid these obstacles whenever possible."

  3. #3
    Yeah I don't see myself going there. I really think the ZF6 is a great trans, shifts really nice and honestly I have to give it credit for being as durable as it is.

    300k miles is no joke, and its not been babied thats for sure. First owner had the new truck delivered to Banks upon receipt from Ford, where the whole catalog (circa 1999) was thrown at it, then she spent 180k miles towing large boats and campers. Then the second owner threw an intake and a new tuner on it and she worked as a welding truck operating out of Eagle for 50k miles. Now i've put another slew of performance parts and 70k on it including 100+ mountain trips and 20+ cross country road trips, driving like a maniac the whole time, especially since I dropped in the 250/100 injectors. Nor should i be surprised that its 6th gear that went, with my current setup even when I have the camper, trailer and SUV in tow i'll leave it in 6th to pull the i70 passes. Traffic willing of course. Gosh thats a lot of torque on those little teeth in there.

    So yeah, i'm bummed... even though i'm tinkering with it constantly and trying to plan out the next sensible repair and/or upgrade steps, I just didn't have a trans failure on my radar. In retrospect, maybe I should have. Reading on a couple of other forums, this isn't unheard of, just not common. Of course, the ZF6 trucks aren't common anyways, and even less so at my power level. I'd suspect a ZF6 would last the lifetime of most of these.

    All that to say, I wouldn't see a compelling reason to go with something other than another ZF6. If I go with a rebuilt trans it would be totally realistic to expect another 200k-300k out of it, and heck even if I go with a partial 'repair' strategy I'd be happy if it held together for another couple years and 50kish miles.

    I'm leaning that way right now. I'm just in no mood to drop 2.5 grand on a whole unit, i'd rather just get it working again and dedicate my funds back to the turbo Duratec project.

    I managed to locate the Ford rebuild manual, which has step by step instructions, then I found a series of u-tube videos detailing a guy doing a complete rebuild.

    I'm happy to report that replacing the 6th gear synchro assembly is in about the first 15% of the disassembly procedure. I'll basically pull 1st (low) and R, then 6th off the main assembly. I could also easily replace the main input bearing while i'm there. I'm printing out the full parts list from Midwest right now, fortunately you can order everything alacarte so i think i'll put together a list of everything likey to be wrong and/or worth replacing while i'm in there and betting that i'm right and ordering it in advance.

    I'll finish going through the parts tonight, but I think its pretty likely that I could get through this at under $300 and one very busy weekend.

    sorry for the rambling... haven't been able to think about much else today!

  4. #4
    I grew up in a transmission shop. We always preached that overdrive was for cruising and if you need to drop the hammer than you should drop a gear to do it. That being said, I'm impressed that yours has lasted like it did. Must be a hell of a gear box.

  5. #5
    Yeah I completely agree with you. Its just geared to low to keep it out of 6th for multi-truck passing. I'll have to check my driving behavior in the future and spend less time in 6th while driving in the mountains. Typically pulling the i70 passes loaded with the camper, 14k trailer and a SUV or CJ I've left it in OD. Might not do that as much in the future!

    I have a pretty good history beating up on drivetrain parts. On my 3rd clutch, 2nd ring/pinion and I've lost count of u-joints. I've been gathering parts to build some trac bars to help those u-joints out, but just keep getting caught up in other projects and keep putting it off until after I buy another plasma to make cutting brackets more funnerer.

    I wanted to get started on pulling it last night. but I have to move the camper, move a bunch of other stuff, get the jeep into the driveway and get the Escape and BMW out of the garage. I use the jeep to maneuver the truck in and out of the garage so I can close the door when not working on it.

    little sunlight and cold weather undermined my enthusiasm and I made it only 20% into that process.

    So i cooked chicken fried steak, drank a manhatten and watched street outlaws... which made me feel bad, because those guys totally make me feel like a lazy ass...

  6. #6
    I am pretty sure my owners manual says not to even tow in overdrive- uh, yeah- duly noted. I'll bear that in mind bombing up the hills in OD... loaded...

    Your garage shuffle made me laugh- since I have a similar routine, except I have the additional requirement of making sure the boss's car always has a spot in the garage.
    If you cross thread a bolt, there is no need for loctite.

    Run whatcha brung... And hope you brought enough.

  7. #7
    You are the first that I have personally heard of a failed ZF6. The only problem I had with mine, was a failed Master Cylinder. That was interesting to have that fail at the exact second I was pulling into a parking spot at WalMart...whoa clutch in and it's still pulling...into my spot and the other cars beyond!! Killed the key and got her shut down just in time!

    I also pulled EVERYWHERE in 6th gear and never worried about it. My FIL has this truck now, but it's got less than half the miles yours does and no hint of issues. I don't likely have the power you are running tho either, nor was I pulling the weight you were. Probably 7-9k max.

    What clutch are you running? I'd love to see a comparison on the gear sizes when you get in there!

    I do miss shifting, but I also LOVE my new PSD, so I guess it's a fair trade thus-far.
    God Forgives, Rock's Don't www.ucora.org
    1973 Bronco, 351 SEFI, Locked, discs, 35's ZF-5spd and Atlas 4spd. 235:1 Crawl Ratio

  8. #8
    Quote Originally Posted by PovertyByJeep View Post
    I am pretty sure my owners manual says not to even tow in overdrive- uh, yeah- duly noted. I'll bear that in mind bombing up the hills in OD... loaded...
    Duly noted... and moving on right along LOL. Like I said, I may do this less in the future, but its kind of a trade off. If I lower the RPM's a bit in 6th it actually runs a fair bit cooler.

    Quote Originally Posted by PovertyByJeep View Post
    Your garage shuffle made me laugh- since I have a similar routine, except I have the additional requirement of making sure the boss's car always has a spot in the garage.
    I typically have that problem as well, though Amber is out of town right now so I have the double advantage of kicking her out of the garage and some more free time. I'll have the busted parts laying on the table when she gets home for budget approval hahaha, welcome home honey!

    Uhg... i'm fortunate to have room for 5 vehicles, a trailer and a camper, but the shuffle wears me out. its dang near more work than actually pulling the trans! I need to get a small trailer to set the camper on so i can move it around and not have to load it into the truck.

    Quote Originally Posted by 74BuckinBronc View Post
    You are the first that I have personally heard of a failed ZF6.
    me too! after all these years picking on friends (and my son...) who've lunched slushbox's i'm catching a bit of grief lol.

    Quote Originally Posted by 74BuckinBronc View Post
    The only problem I had with mine, was a failed Master Cylinder. That was interesting to have that fail at the exact second I was pulling into a parking spot at WalMart...whoa clutch in and it's still pulling...into my spot and the other cars beyond!! Killed the key and got her shut down just in time!
    that would be exciting! reminds me of a time we were camping on BLM land and I had my son re-position the truck, it was in low range and pushing through the brakes, he just panicked and even at idle it was just crawling away while he stood on the brakes harder. fortunately the window was down so i ran up, jumped into the window and shut it down.

    Quote Originally Posted by 74BuckinBronc View Post
    I also pulled EVERYWHERE in 6th gear and never worried about it. My FIL has this truck now, but it's got less than half the miles yours does and no hint of issues. I don't likely have the power you are running tho either, nor was I pulling the weight you were. Probably 7-9k max.
    Honestly I think pulling in 6th is totally fine for 999/1000 people. I think i'm a unique combo of good power, stupid driving and bad luck.

    Quote Originally Posted by 74BuckinBronc View Post
    What clutch are you running?
    Currently running the South Bend dual disk street clutch rated at 650/1300. I can't say enough about how good this clutch is, its better than the stock clutch in every way, its been totally reliable for around 40k miles so far and I expect it to last a long time. The only downside is cost, not a cheap unit at close to 1200 bucks.

    Previously I was running the South Bend 1944 organic single disk, which I was also extremely happy with and is again superior to the stoker in every way, but I had outgrown the capacity of the unit and swapped it out while it was till fairly fresh.

    For anybody running the ZF6 one of the first things i'd recommend is getting a South Bend, just pick your unit based on your power level, or if your purse can handle it just get the dual disk.

    Quote Originally Posted by 74BuckinBronc View Post
    I'd love to see a comparison on the gear sizes when you get in there!
    I'm actually pretty geeked to check it out! I might have to dig out some other old trans parts and take some photos with comparison parts.

    Reading on the interwebs, I guess the gear cluster weighs over 120 pounds on its own. hopefully I don't pop my back out!

    Quote Originally Posted by 74BuckinBronc View Post
    I do miss shifting, but I also LOVE my new PSD, so I guess it's a fair trade thus-far.
    me too man... driving the 540 these last couple of days I feel kind useless without the 3rd pedal!

    sometimes I contemplate how nice it would be to have a new truck, lack of proper shifting holds me back more than any other factor. I don't know why, but shifting your own gears is a special kind of fun and i've never loved a vehicle with an auto.

  9. #9
    well, got the trans out, split the case and I was able to inspect 6th gear, as well as 1st and reverse. I didn't get the entire gearpack out of the case and onto the bench. its HEAVY! I'm no weakling and am fairly athletic, but your sports better lean more towards lifting and less towards rock climbing and mountain biking if you want to just pick this thing up and out of there! I'll get a neighbor over or use my hoist after work to pick it out and look over the rest of it.

    Preliminary findings are interesting, and lean me towards optimism that I might fix this thing without replacing internal parts! knock on wood, but I just may have to relinquish the title of ZF6 Killa.

    Onto some pics and the rest of the story.

    first up, yeah... the gears in this thing are huge! totally dwarf a beer can. I've taken apart several transmissions; including WCT5's, T56's, SM465's, T90's and the ZF6 is in another league as far as my experience goes. neat stuff, as much as pulling my trans apart wasn't really on my list of stuff I wanted to do right now, i'm enjoying checking it out.



    Next up is out magnet, it slides into a little slot on the back half of the case, in theory you could leave the trans in the truck, pull the back half of the case and give this a look. Pretty neat design. Anyways, i'll tell ya that I was expecting to find all sorts of debris attached to this, and was really prepared to find synchro parts in the bottom of the case. Instead its just a little bit of fine fuzz, honestly less than I would expect for any hard used gearbox with 300k miles. So at this point i'm pleasantly surprised but honestly kind of scratching my head. Fluid looked pretty good as well.



    So time to get to the meat of it, here's a detail view of the 6th gear and synchro assembly. I was totally prepared to bet $300+ and order replacement parts for this in advance, I was SURE these parts would be lunched and I was pretty baffled about how you could be straight up missing a gear and NOT have these parts annihilated. But, there you go, not only is this stuff not destroyed, it dang near looks pristine.



    Same view after I engaged the gear. Its slid smoothly into place and though I operates smoothly by hand. Clicked it in and out several times and everything thus far is looking hunky-dory.



    Okay, so I haven't been able to inspect the other side of the gearset, and I will later tonight, but at my level of understanding i'm not yet picturing what could be wrong with this. Maybe the roll pin on the shift rail sheared? If so, that won't be a big deal to take care of.

    As you can see by the PBR can above, I had a beer going so wanted to at least tinker around until that was gone before I call'd it a day. So I decided to grab the shifter and stick that back on with a pair of bolts and mess with it a little bit. What I found surprised me and explained the fluid leak around the shifter. Apparently the bolts installed around the shifter are TOO LONG and won't actually snug the shifter down onto the trans! Being that you have to install the shifter in the cab, and I always install it with a healthy coat of silicone, so it always felt like it snugged up just fine, but apparently my shifter was previously held in place more by silicone and less by bolts. Given that its been this way for quite awhile and not really leaked, that silicone must have held pretty well before and now wasn't stuck at all.

    So maybe, just maybe, my issues here is little more than the shifter being miss aligned and not pushing it all the way into gear. Perhaps when driving if I had tried it a couple more times I could have actually found 6th, but instead I was nervous about hucking around broken parts and gave up to drive in 5th pretty quick. Maybe that loud bang was just popping out of gear?

    You can clearly see that the bolts are at least a sixteener two long. I'm actually a little bit stoked, to think I can make my shifting feel more crisper by fixing this is kind of an upgrade. I know this truck has had at least one clutch swap prior to my ownership, so i'll blame that guy by using the wrong bolts. or... maybe they are the right bolts and this is supposed to have a gasket? At any rate, I think i'll just get shorter bolts.



    So... there we have it so far. I'm going to pick up some fluids, silicone and new bolts after work, then i'll use the hoist to pull the full gearset out and give everything a really close look over and baring no further discoveries I'll start putting things back together.

    Thinking further... I might also pick up an assortment of roll pins just in case the roll pin sheared on the 6th gear shift rail.

  10. #10
    I hate that there wasn't an obvious failure tho because nothing sucks more than thinking you got it licked to reinstall and find you still have the problem.

    The loose shifter cover could certainly not allow gears to fully mesh, but with the tall bosses for the bolts and only a 1/16" gap, I'm not sure that would be enough to cause it to jump out of gear. What about the interface between the end of the shifter and the fork? Any slop there? I really know very little about tranny's, so I hope it really is as simple as fixing the loose cover, but sometimes with the amount of effort involved in a project like this, you'd almost rather see an obvious sign.

    Looking forward to the rest.

  11. #11
    tacotoy's Avatar
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    Quote Originally Posted by 74BuckinBronc View Post
    I hate that there wasn't an obvious failure tho because nothing sucks more than thinking you got it licked to reinstall and find you still have the problem.

    The loose shifter cover could certainly not allow gears to fully mesh, but with the tall bosses for the bolts and only a 1/16" gap, I'm not sure that would be enough to cause it to jump out of gear. What about the interface between the end of the shifter and the fork? Any slop there? I really know very little about tranny's, so I hope it really is as simple as fixing the loose cover, but sometimes with the amount of effort involved in a project like this, you'd almost rather see an obvious sign.

    Looking forward to the rest.
    with the pics that you have, that sounds more plausible that there is something wrong with the fork assembly and the shifter.
    hookers and blow!

  12. #12
    Only minor progress on this as i'm back in TX now, our uncle passed away late Friday, so I jumped in the 540, booked it south and will be down here until Sunday.

    I did manage to get the gearset out of the case and onto the bench, I had to use the engine hoist to lift the thing, its a pretty impressive chunk of metal! In a perfect world I wouldn't have to mess with this, but in all honesty i'm finding it pretty neato to check out and mess around with.

    Well, here's the bad news... now that I have it on the bench and I can grab both the input and output shafts and rotate everything through various gears, there is certainly something failed in the 6th gear synchro assembly, but inside where I can't see it yet. I've taken the shift forks off but I got stuck not having a big/strong enough set of snap ring pliers. My gear puller isn't big enough to yank off the 1st/reverse anyways so i knew I was shutdown on Friday. I do have a very big puller, but the one required is HUGE.

    So later this week while i'm down here or after I get home i'll snap up a couple more tools and get this stuff dissembled to verify the parts order, i'll take some pics and post up. while I have the downtime i'll also think about what other parts/bearing will be easy to replace (main input bearing for sure, its in fine shape, but showing some typical wear and is a piece of cake to swap out).

    While i'm down here we have a summit racing not far away, i might go browse around and pic up a trans cooler. reading a couple of other threads where others have had similar failures the advice was to upgrade coolers and monitor temps. supposedly, if you have the power to haul in up grades in OD its the heat that does it in and some have have had good luck adding a larger cooler.

  13. #13
    Camp Cook Geek cheftyler's Avatar
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    Sorry to hear you lost your uncle.
    "Blow and Hookers can change the World. - Gags
    Quote Originally Posted by scottycards View Post
    MJ has no lethal dose. You might crawl under your couch and eat M&M's all day if you get too high, but it ain't gonna kill you.

  14. #14
    Quote Originally Posted by cheftyler View Post
    Sorry to hear you lost your uncle.
    Thank you very much. He was a very cool guy, a father figure to my wife and a mentor to many and one of the most successful cattle guys in Johnson County TX. He'll be greatly missed but lived a long and awesome life. He was also a fellow gearhead, and was honored properly when we used his Hellcat to lay down a pair of looooooooong stripes exiting the small rural cemetery.

    Back to our regular transmission.....


    I got the R-1 gearset and the failed 6th gear and synchro assembly removed yesterday. This stuff is really pretty simple to work on, especially when you have the proper tools.

    Of course... proper tools we do not have, so some ingenuity was of course required. Typical of any visit to Harbor Freight, I bought a couple of tools that looked like they might almost work, took them home and promptly broke/fixed/modified as necessary.

    First problem was the snap rings, they are HUGE and despite having three really nice pairs of snap ring pliers I had nothing big enough to open these far enough. Harbor Freight didn't appear to have anything either, so I bought the biggest/longest pair of needle nose pliers (like 2' long) for like $12 and ground the tips down to fit the rings. After some trial and error to get the tips fitting correctly this worked perfectly.

    Next up I needed a HUGE gear puller. HF had a couple of large hydraulic pullers, but at $80+ I wasn't willing to spend that on an HF tool, so I purchased the 8" puller for like $10 or something and decided to give that a shot.

    Of course it wasn't nearly big enough to reach around the R gearset and grab the back of the 1st gearset. You can pull R separately, but this will leave the needle bearing race on the shaft, so you'll have to figure out how to pull behind 1st or you can cut and crack the bearing race and replace it. I tried to use the 8" puller to pull R, but promptly stripped the shaft of the puller. Of Course!

    So I disassembled my 6" HF puller to combine its parts with the 8" puller, oddly enough the 6" puller is built much more burly. While I had it apart I realized i could drill holes in the ends of the 8" puller legs to make it longer, and combine the side bars from both pullers to make it even that much longer. Doing so, it was long enough to reach behind 1st gear, I hit it with the air impact and it worked like a charm. Sorry, I should have taken a photo of this monstrosity as it was pretty wacky looking. Amber commented that it looked like I was performing surgery on a Decepticon.

    Everything on R/1 looked great, so it got set aside and I re-assembled the puller monstrosity to fit around the 6th gear and pulled it right off. Of course, you end up in a similar situation where the roller bearing race is still on the shaft, so you can't get the synchro hub off, and there is far too little clearance between the hub and the center plate for a puller. So this bearing race got sacrificed, I cut about a 1/3 of the way through it with a dremol cutting wheel on a die grinder, gave it a wack with a cold chisel and it cracked right in half. This is standard procedure on a couple of tran's i've worked on and fortunately the races are affordable.

    Thus concludes our disassembly, so I cleaned up, cooked a tri-tip steak for dinner and went back out later to examine the carnage.

    First up is our 6th gear synchro ring, as you can see it clearly just started melting itself.



    And here is its mating surface on the 6th gear...



    And here you can see that the synchro ring melted down enough that the gear began to eat into the synchro hub. I guess I snapped this photo before completing disassembly, right in front of the hub is the roller bearing race that I cut and cracked to remove the hub. You can also see a little scuffing on the center plate as things lost tolerance, fortunately this is superficial.




    So there we have it... looks like i'll be replacing the 6th gear, the 6th gear synchro assembly and a bearing race. If i'm to hazard a guess as to what happened here, i'll actually go back to blaming that shifter. I think when that silicone around the shifter cut loose I began loosing fluid, eventually getting to a point where the gear at the top/back of the case was being under lubricated, at a time when I was on a cross country roadtrip and spending hours at a time in that gear resulting in it over-heating and melting down. In going through parts lists apparently the shifter is supposed to have a gasket, since mine never had one I wasn't aware that it should have.

    so here is what my shopping list is looking like right now. I'm not yet entirely sure that this is the correct synchro ring.

    Also, as far as nomenclature goes, I've been referring to gears as 1st through 6th, apparently the correct nomenclature is is Low and 1st through 5th.

    Last edited by euroford; December 11th, 2017 at 12:24 PM.

  15. #15
    vs parts list from Midwest trans, about double the cost. I'm not sure what the part quality difference is, but at the moment i'm inclined to think about the cheaper parts.


  16. #16
    Yeah, Allstate gear pricing makes it very affordable to do you own work. But the Midwest price seems like it's about 40% of a full rebuild.

  17. #17
    Quote Originally Posted by 74BuckinBronc View Post
    Yeah, Allstate gear pricing makes it very affordable to do you own work. But the Midwest price seems like it's about 40% of a full rebuild.
    agreed, i'll be going the Allstate route. At about $225 it brings the whole project down to a fairly painless level. I was very confused about making sure I had selected the correct synchro ring, Allstate's website lists the 3rd, 4th and 5th (4th 5th 6th in my vernacular) rings as identical, and they do look so for as well as I can see them, however Midwest had separate part numbers for each of the three rings. After digging a little bit I found further evidence that they are the same, and then realized that when you click each different rings on Midwest's website it adds the same part to your cart. Kind of confusing...

    I'll get stuff ordered, and then its onto the worst phase of the project.... cleanup....

    Since it was leaking pretty substantially from the shift tower, the cases, all of my tools, my shop, the floors, everything, is a filthy mess. I'm usually diligent about at least powerwashing the underside before I take on a project like this, I now sincerely regret not doing that, but i'm not sure how much it would have helped. The case is going to require a proper scrubbing.

  18. #18
    I own an old bronco - I get the mess. I only worry when it's NOT leaking!

  19. #19
    yeah i know all about that! I actually designed my flatfenders belly skid to act as a diaper and help contain her constant desire to mark territory.

  20. #20
    additional minor update...

    while cleaning everything up last night I noticed that the Counter Shaft Spacer which sits behind the syncro hub was also worn, so another $11.99 part gets added to my cart for a grand total of $236.40. Seeing this spacer worn really worried me that it might have dug into whatever is behind it. Fortunately this is a shoulder on the countershaft which is clearly much harder and suffered no damage. Loss of tolerance in this space explains why the syncro assembly was able to scuff the center plate.

  21. #21
    survived the holidays without the truck! my wifes Escape thoroughly enjoyed the opportunity to play adventurmobile for a long weekend. We didn't travel to see family this year so instead we road tripped it out to Ouray. Had lunch with friends in Breck on the way out, stayed in Ouray and spent Christmas day in Telluride and then met up other friends in Fairplay. I highly recommend the Christmas buffet at the Altezza restaurant, and a 4:15 reservation to take in the alpenglow views.

    poor thing has been sitting disassembled as the holidays consumed all time and money. fortunately, parts are ordered now and should be in in the next couple of days. In addition to trans parts I also ordered all new HD Spicer U-joints to rebuild the driveshaft while its out. With the substantial increase in HP/TQ i've made a bit of a habit out of destroying u-joints and that is getting old. Of course, this has a lot more to do with axle wrap than the joints themselves, so I also went on a spending spree with Ruff-Stuff and ordered up some big-ass heim joints and plan to build myself a set of traction bars right after the trans project is done.

    Also discovered a busted front sway bar mount, but some new bolts and a little bit of TIG took care of that.

    The last side project was to redo my shift lever. I have an underdash three gauge pod which holds my fuel pressure gauge, my Hydra switch and my Turbosmart boost controller*. when static it clears by about 3/8", but the shift lever has a rubber flex joint, so every time i go for 1st or 3rd the lever clacks into my FP gauge. So, i cut off the base and the top of the shift lever and pressed them into a steel tube and welded it up. Not only does this resolve my gauge-clack issue but i'm looking forward to the more direct feel of a solid shift lever.


    *As a total aside, I get a chuckle out of how when you first start modding a 7.3, unplugging and locking down your wastegate is a good "mod", but then eventually you come full circle and really using your wastegate becomes the way to go! I highly recommend a good electronic boost controller as an excellent mod when you start running a high amount of boost. In my DD tune i have it set to 28psi and in my Race tune I have it set to 42psi and I think the controller helps spool the turbo quickly and massively reduces backpressure and EGT's under full boost and likely has a notable improvement on volumetric efficiency and power. Along with the 360 degree thrust bearing upgrade I think this has much to do with the good performance and reliability I've achieved from a stock-ish turbo.


  22. #22
    What design are you considering for a traction bar? Any rubber joints in it at all?

  23. #23
    Quote Originally Posted by 74BuckinBronc View Post
    What design are you considering for a traction bar? Any rubber joints in it at all?
    Nope, I seriously considered that but i'm going to go with heims at both ends. I've been playing around with a design that replaces the shock mounts with a bracket that will include both the shock mount and the traction bar mount. Then i'll fab up some frame mounts and attempt to make the bars as long as practically possible. I'll post some pics as I get rolling on it.

  24. #24
    The reason I ask, is that a single bar that doesn't swing on the exact arc of the springs will induce a harsh ride. Best design I've seen attaches at the axle at two points, and y's into one and then attaches to the frame via a shackle. That allows for all the movement it needs, but keeps the axle from twisting up. I'm thinking I need one for my bronco as well and if the frame mount is a johnny joint, you don't lose any flex.

  25. #25
    Haku's Avatar
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    Interesting read and one I understand as my ZF6 also grenaded over the summer. I have other vehicles and no easy way to remove the transmission right now (it would be in the driveway on my back) and I couldn't swallow the prices transmission places were charging to remove and replace a transmission.

    Mine happened while I was driving to Idaho for a rafting trip over the summer. Truck had my rafting gear, but wasn't pulling a trailer.

    Previous to this, my truck had broken its transfer case off the back of the transmission housing twice. The whole flange that holds the transfercase on the transmission broke. its evidently fairly common to happen and usually occurs after a u-joint goes or some other major large vibration event happens. Luckily its a relatively easy fix and can be done with the transmission still in the truck...you just have to remove the t-case and remove and replace the rear extension housing and put the t-case back on. The first time it happened, the transfercase litterally fell off and hit the ground while I was towing a trailer from Fairplay back to Denver. It messed up the output on the transmission and the input on the t-case, so both needed to have parts replaced and I had A1 transmission do it for me. They fully rebuilt both the transmission and t-case but said they used the existing syncros. This was 3ish years ago. The second time it happened was over this summer and I caught it before it did any damage outside of the extension housing so I did that on my back in the driveway.

    Everything seemed fine, though I could hear a slight high pitched whine. i knew I had fluid in the transmission since I had recently done the extension housing swap so I kept going as I was a few hours into the trip already and it still felt fine. Just as I crossed the Wyoming Border on 287, I heard a large clunk and lots of crunchy noises came out of the transmission and I lost drive immediately. I thought I was SOL and was gonna have to get it towed home, but figured out that 4th gear still had some drive. No reverse, and no go for any gear other then 4th. I managed to limp it home in 4th gear, transfered my stuff to another car, and headed for Idaho again. I actually had a castastrophic thing happen to that car on the way home as well...but that is a story for another day. I can't help but think that I messed something up when I did the extension housing, but it seemed to go rather smoothly so its hard to say.

    I actually decided to get a Toyota Tacoma when I got home and it has been reliable, so motivation to fix the truck has been low. The Ford has 287k or so on it, so I suppose this kind of thing is to be expected. Sucks because I had just spent $2k on putting new stage 1 injectors into the truck. Other then that plus a Hydra tuner, it is basically a stock F250.

    I'd love to get it on a lift and/or get some help dropping the transmission, but I'm a bit scared to find out. I talked to a few transmission places, and they definitely were painting pictures of doom and gloom and having to basically buy a new transmission at the cost of like $5-7k. I know you can get junkyard ones for cheaper, but its still gonna be spendy. I only paid $6k for the truck, so its hard to justify spending even another $2k on it.

    A-1 said they would have a look at it but they just rebuild transmission and don't do the actual removal. They are one of two places that most of the other transmission shops in town send their manual transmission for rebuild, so presumably they know what they are doing.

    Just thought I'd share my story and see what people thought when I saw this thread pop up. I definitely miss the truck and would like to get it back on the road, but not sure its the financially responsible way to go. The engine runs strong though and it feels like it has more miles left in it.
    Last edited by Haku; January 3rd, 2018 at 01:59 PM.
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  26. #26
    Quote Originally Posted by 74BuckinBronc View Post
    The reason I ask, is that a single bar that doesn't swing on the exact arc of the springs will induce a harsh ride. Best design I've seen attaches at the axle at two points, and y's into one and then attaches to the frame via a shackle. That allows for all the movement it needs, but keeps the axle from twisting up. I'm thinking I need one for my bronco as well and if the frame mount is a johnny joint, you don't lose any flex.
    If i was building a traction bar for my jeep, thats definitely the way that I would do it! However, the truck isn't really an off road vehicle so i'm not worried about articulation. The basic long bar setup seems to be the common way its done and people seem to be happy with it. I think with the fairly flat springs, not a lot of travel and the long length of the bars, you don't run into the problems you'd have with a Bronco or a jeep. we'll see i suppose!

    Quote Originally Posted by Haku View Post
    Interesting read and one I understand as my ZF6 also grenaded over the summer. I have other vehicles and no easy way to remove the transmission right now (it would be in the driveway on my back) and I couldn't swallow the prices transmission places were charging to remove and replace a transmission.
    Other than the massive size and weight of the trans, i've found it to be about the easiest one i've ever pulled. All of the components are easy to access and its very straightforward. I've had mine in and out four times now, and i've done it in the driveway during the summer. So, when the weather is nice and you acquire a round-tuit I wouldn't hesitate to get it pulled out. You MUST have a trans jack though, the tcase and trans are both far too heavy to manhandle.

    Quote Originally Posted by Haku View Post
    Previous to this, my truck had broken its transfer case off the back of the transmission housing twice. The whole flange that holds the transfercase on the transmission broke. its evidently fairly common to happen and usually occurs after a u-joint goes or some other major large vibration event happens. Luckily its a relatively easy fix and can be done with the transmission still in the truck...you just have to remove the t-case and remove and replace the rear extension housing and put the t-case back on. The first time it happened, the transfercase litterally fell off and hit the ground while I was towing a trailer from Fairplay back to Denver. It messed up the output on the transmission and the input on the t-case, so both needed to have parts replaced and I had A1 transmission do it for me. They fully rebuilt both the transmission and t-case but said they used the existing syncros. This was 3ish years ago. The second time it happened was over this summer and I caught it before it did any damage outside of the extension housing so I did that on my back in the driveway.
    Holy cow! I haven't heard of that one before! that would suck for sure! I guess its a good idea that i'm putting in new u-joints and hopefully reducing those vibrations with the trac bars!

    Quote Originally Posted by Haku View Post
    I'd love to get it on a lift and/or get some help dropping the transmission, but I'm a bit scared to find out. I talked to a few transmission places, and they definitely were painting pictures of doom and gloom and having to basically buy a new transmission at the cost of like $5-7k. I know you can get junkyard ones for cheaper, but its still gonna be spendy. I only paid $6k for the truck, so its hard to justify spending even another $2k on it.

    A-1 said they would have a look at it but they just rebuild transmission and don't do the actual removal. They are one of two places that most of the other transmission shops in town send their manual transmission for rebuild, so presumably they know what they are doing.

    Just thought I'd share my story and see what people thought when I saw this thread pop up. I definitely miss the truck and would like to get it back on the road, but not sure its the financially responsible way to go. The engine runs strong though and it feels like it has more miles left in it.
    Well, like I said, pulling the trans isn't that bad, if I can help you out let me know. I think you can also score a rebuild in the $2.5k range, so thats not toooo bad. Maybe if you get it pulled out and i can help you diagnose and DIY the rebuild. Having done this one I can honestly tell you that its not a bad job, definitely something a shade-tree mechanic can do.


    My parts from All State were supposed to get in Monday the 8th, but I guess UPS was on the ball so they showed up Friday! As soon as the delivery notice showed in my email I closed down the office and bolted out the door. When I got home I pulled open the package to inventory and inspect the new parts and was shocked to see that I was missing the 6th gear bearing spacer! My first thought was that I forgot to order it, so i dug out the packing list and found they hand scribbled the words "drop ship" next to that one part.

    Of course... that's the 1st part that goes one, so after 10 minutes of organizing my forward progress was abruptly shut down. with no notice if that part was back-ordered or what the deal was. Saturday afternoon I was sitting in the living room drinking a beer with my wife after a mountain bike ride and a VERY grumpy UPS driver showed up with the missing part, so game on! After cooking dinner my wife plopped in front of the tube (technically, a front projector) and I was out to the shop.

    Given my lack of professional grade tools, I was a little worried about what it would take to get bearings, races, ect pressed back on. Especially the 6th gear roller bearing race. its a tight tolerance fit so you have to make sure its fully pressed in place, and as you know from my previous post I have no way to pull it back off. So either I get it on first shot or i'm screwed and would have to cut it back off and order another one.

    So, I must fully compliment those crafty Germans at ZF, they have the tolerances DIALED. Using my wifes state of the art bearing warmer, I cooked the two roller bearing races the output washer and the output bearing for about a half hour at just less than 300 degrees, added a liberal coat of assembly lube and everything just slid right together. no pressing, bashing or fussing whatsoever. after 5 minutes of cooling its permanent.

    baking up some truck parts! much thanks to my lovely assistant there in the background.



    new 6th next to the old 6th. pretty obvious what our big failure was! quality of parts from All State appears to be very good!



    and here we go! gearset all back together! I was afraid that getting the shift forks back on would be a big pain the arse, and it kind of was. getting things lined back up was not to bad, but installing the roll pins is a total pain. you have beat on those things way way way harder than you really want to.




    With the gearset reassembled i called it a night, made myself a Manhatten and watched an episode of Keeping Up With The Lothbroks. Sunday morning my wife worked on a carpentry project while I dropped the gearset back into the case and got that all buttoned back up again and got everything sorted to begin re-installation in the truck. The weather was too nice to jump back into that though, so i went off on another mountain bike ride and then the wifey and I hung out at Front Range Brewing for a bit and then grabbed a burger that the Waterloo.

    I reckon i'll ditch work a bit early today and jump into re-installation later today. Man, I would LOVE to drive that thing to work tomorrow.

  27. #27
    Great to see it coming back together! Hope stabbing it all back in goes without a hitch.

    Back to the traction bar...I know you've done your research so I am sure you have your bases covered and I am anxious to see what you come up with. But it still makes me a bit nervous what damage could occur if the geometry isn't just right. You have opposing forces with springs wanting to travel rearward as the suspension compresses and a solid traction bar wants to stop that. If you have a good load, things could already be binding up. So, while the shackle design does allow for uninhibited flex, it's just as good for just normal flex.

    Interestingly most of the aftermarket ones are solid. Perhaps that is because they have the geometry sorted? I did see one from BDS that has a spring on the inside allowing it to give some. That would be a good compromise.

  28. #28
    Haku's Avatar
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    I'm not gonna quote all your responses to my stuff...I'll just respond. Definitely glad to see the new parts get put back together.

    I've pulled mine out twice as well, but both times I had a lift. One time I didn't have a high lift transmission jack and just used a tool box and landed the tranny on it by dropping the whole truck with the lift. I agree that overall its not too bad other then the weight of it. Luckily, I have a friend with a lift, and in exchange for buying him a high lift transmission jack (from HF for $200) he said he'd let me put it on the lift and help me remove it. I thought those jacks were 5 times more expensive but HF to the rescue again. I'd definitely do it in a pinch, but after pulling the t-case in the driveway on my back over the summer, I'm not in any hurry to do it that way again. A transmission jack would have helped a lot I'm sure.

    If you are willing, I'd love to bring it over and have you help me take it apart. I'll probably try A-1 just to see what they say, but if they say its toast I might get a second opinion from ya.

    The extension housing thing is mostly with heavy vibrations. The first time it happened the bolts backed out a bit on one of the driveshafts and is started from there. The second time it was a bad u-joint that went from being unnoticeable to catastrophic in the matter of an hour. New unjoints and minimal gear slop will help for sure. Proper torqueing of the t-case bolts and either locktite or good lock washers (I use Nordlocks now) to make sure the bolts don't back out are key too. Not a fan of how they leave the t-case basically unsupported beyond those 6 bolts that mate it to the transmission. Thinking about making a Toyota FROR style crossmember that bolts to the rear output support housing bolts.

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