M5OD has begun popping out of first and sometimes second

[Shran]

Sure, see below. I'm wondering if I dropped a piece of dirt or something in during assembly and that's what caused the race to sit crooked? I have no idea. Maybe it was like that before. Mind boggling.

Here's some pics of the retainer, hard to capture the wear on it in a picture but I put a good retainer under it for comparison

2nd gear. Some of the teeth are missing tiny chunks/rounded off... ordered a replacement

1/2 hub/slider, teeth look fairly rounded off to me. will replace

3/4 hub/slider, will replace this one too

Center bearing race

Input shaft bearing race

 

[Transman304]

Definitely have major wear on parts. Could the shim under the race have gotten misaligned and caused it not to set completely?

 

[Shran]

Definitely have major wear on parts. Could the shim under the race have gotten misaligned and caused it not to set completely?

Maybe? Man... I dunno. I spent a lot of time measuring and stuff on this one and thought I had it dialed in perfectly. The first one I did, I had no idea what I was doing and reused a lot of parts that I'd probably think are questionable now. I've got 4 years and probably 30k on it, no issues... built one for my buddy too that has been good so far.

I feel like I must have done something wrong when I assembled it or there is a problem with a part that isn't apparent to my untrained eye.

 

[Shran]

I finished reassembling this a couple nights ago. Replaced the rear bearing retainer, 2nd gear, both hub/sliders on the main shaft, and all of the bearings. Fingers crossed it works this time.

One other weird thing I found was the pocket bearing between the input and main shafts had some really crazy wear. The ends of the rollers had started to eat into the bearing cage and the whole thing was stuck inside the input shaft hard enough that I had to pry out each of the rollers before the cage would come out. Inside of the input shaft looks fine, I don't think that was the problem, looks to me like the bearing itself was starving for oil or just a crap bearing to begin with. The oil trough was clear and the slinger was installed correctly so I have no idea why it would have starved for oil.

The other trans I did for my buddy at the same time as this one is still working great, he has put 2500 miles on it so far and it appears to be very healthy.

 

[4x4prepper]

> Could that cause or at least contribute to my popping out of gear issue?

If you have loose or gone bolts at the top of the transmission where it mounts to the engine. It allows the transmission to flex under torque. If I remember correctly how I solved it was drilling through the threaded motor side, from the transmission, and using grade 8 bolts/washers/nyl-nuts to solidly connect the transmission to the engine. I think it dawned on me when I had the transmission out and counted the mounting ears vs. the amount of bolts I removed. It was missing two at the top.

You buy something used, remove all the bolts, put them all back with no extras, it might not occur to you since you do not do transmissions everyday, that bolts might be missing because the threads stripped out. Which can happened when people use the bolts to force the transmissions to mate to the engine. Or they simply leave them out because they are hard to get too, like the top middle two on some RBV combos.

 

[4x4prepper]

After seeing the wear on the "input shaft bearing race", I am wondering if it is a lubrication problem? Especially if your buddy has no problem with his build.

Sorry to see your transmission giving you this much trouble$

For the 1st time in 40 years, I just nuked an OEM locking hub (on my B2). Never even did that snow plowing with Broncos and Blazers. I fell victim to Georgia clay mud, this is the first time I never could self recover in an hour or so. Mile Marker hubs everywhere are out of stock, so, I had to go with Warn hubs at $250 plus tax. Unless I want to winch my way out of the mud with my two axle trailer a few hundred feet. A simple thing has turned into a $400+ worth of parts nightmare, so, I feel your pain

 

[Shran]

I'd hope that I'm not missing any bolts, I'd be the last person to leave them out after having the trans out of this truck four times now

It's back together, I've put about 300 miles on it now and it seems to be fine. I'll change the fluid at about 1000 or so and see how it looks. I will say, it has never shifted as nice as it does now - replacing those hub/slider assemblies and 2nd gear made a huge difference.

If the fluid is full of metal again at 1000 miles... I'm gonna pull the trans, light it on fire, and put my old one back in.

 

[Shran]

Update: I changed the fluid yesterday at 1000ish miles. Had some random mixture of various ATFs in it before for break in. There was just a little fuzz on the drain plug this go-round, fluid had a small amount of metallic particles suspended in it while warm but not more than I'd expect from break in. Other than the shifter being a little tight when the trans is at operating temp, it's been working perfectly. Think I'm good to go.

 

[Shran]

Well, F M L

Went out today with some friends and ran around the back roads... this fawking thing started popping out of 1st again and was making noise in 1-2-3. I think it's actually worse than before. I don't know how it was fine for months and 2000+ miles and just decided to grenade itself today on a dirt road.

I think I'm going to reseal the tailhousing and shift cover on my old one and put it back in. That one was kinda worn out and leaking a lot but I never had other issues with it. This is ridiculous... I am just at a total loss right now.

 

[scotts90ranger]

I'm betting it's something with the bearing between the input and output shafts... if there's torque between the shafts it's going to do odd things, I'm not going to try to wrap my mind around the direction of forces but it could unload the shaft or change the alignment just enough to knock it out of gear...

 

[Shran]

That bearing was trashed when I took it apart the second time! I had to pick the needles out with a screwdriver before the cage would come out. The needles had worn into the cage quite a bit, and it was very sloppy. I am expecting the same thing this time.

Soooo...what causes that twice? Input shaft is new, was no evidence of wear on the main shaft where that bearing rides.

I have a theory that maybe I didn't get the trans lined up with the pilot bearing and pushed it through the flywheel too far while I was installing the trans. That would allow the clutch disc to walk sideways, putting a load on that bearing and the front input shaft bearing... I guess I will have to confirm that when I pull the trans, sounds far fetched, but maybe?

 

[Bill Zone]

I know a transmission guru that pretty good at phone diagnosis. I used help him out w/ the R&R's when he got slammed, and would watch him rebuild these things w/ his eyes closed. Everything was always spotless during assembly. A lot of guys/shops that had a crappy rebuild or unique problem, or need a race build will seek him. Might be worth it to call and pick his brain.

S K Performance Transmission · 9900 Glenoaks Blvd STE 1, Sun Valley, CA 91352

★★★★★ · Transmission shop

goo.gl

 

[Bill Zone]

I am hitting this guy up, now. Thanks for the referral. (Bill and his 98 4.0 4x4.) (skperformancetransmission.com)

 

[Shran]

Small update: think I can rule out the pilot bearing theory. I pulled this transmission, inspected the clutch/flywheel/etc and put my original trans back in. Pilot bearing looked and felt fine and it was installed just like the other 10,000 other pilot bearings I've installed... flush with its little hole in the flywheel.

I think I am going to find a different 4.0 case, with different front and rear bearing retainers, and a different top cover, and put my guts in it with another new bearing kit and hope that it's just this case that's junk, or something. Maybe throw a second new input shaft at it too. It's just money............................................................................................