driveshaft carrier bearing

[Suprabrew]

Am getting ready to pull rear driveshaft on the 4WD to replace the carrier bearing on it. Does anyone have experience with this (looking at you Camiot lol). I don't see much instruction in the manual. Just don't want to find unexpected problem with the replacement. Thanks

[FMS88]

It's pretty straightforward. First remove the center u-joint. If re-using the u-joint, note the positions of the snap rings, journals and joint so everything goes back to its original location when reinstalled. Make mating marks on the drive shaft and center yoke, then remove the locknut and center yoke from the short, front shaft. Pull the outer metal mount and rubber off leaving the bearing exposed which you can then remove with a puller. Apply grease to the inside of new bearing and install the new carrier bearing assembly onto the front shaft. If the new assembly has a rubber dust/bearing seal on one side, install it with the seal toward the front shaft. Install the center yoke with the marks aligned and tighten the lock nut to 120-160 ft/lbs. Install the u-joint and snap rings. If installing a new greaseable u-joint, point the zerk fitting toward the rear shaft and in a position that mirrors the rear joint's.

[Suprabrew]

It's pretty straightforward. First remove the center u-joint. If re-using the u-joint, note the positions of the snap rings, journals and joint so everything goes back to its original location when reinstalled. Make mating marks on the drive shaft and center yoke, then remove the locknut and center yoke from the short, front shaft. Pull the outer metal mount and rubber off leaving the bearing exposed which you can then remove with a puller. Apply grease to the inside of new bearing and install the new carrier bearing assembly onto the front shaft. If the new assembly has a rubber dust/bearing seal on one side, install it with the seal toward the front shaft. Install the center yoke with the marks aligned and tighten the lock nut to 120-160 ft/lbs. Install the u-joint and snap rings. If installing a new greaseable u-joint, point the zerk fitting toward the rear shaft and in a position that mirrors the rear joint's.

Damn! what a perfect and complete reply. Thanks FMS88. Did the job today and it went exactly as you directed. Thank you for that kind effort and reply.

[xboxrox]

Damn! what a perfect and complete reply. Thanks FMS88. Did the job today and it went exactly as you directed. Thank you for that kind effort and reply.

FMS88 one of the best super helpful MR50 members

[FMS88]

Damn! what a perfect and complete reply. Thanks FMS88. Did the job today and it went exactly as you directed. Thank you for that kind effort and reply.

You're most welcome. I'm trying to find a tranny I can rebuild as a spare, but they're hard to find. If I do find one, I may come knocking on your door for help. LOL
Cheers

[Suprabrew]

That would be an honor sir.

[Suprabrew]

FMS88, if you find a spare tranny and know that it shifts ok, I wouldn't open it up. If it is noisy, it's probably the input shaft bearing (accessible from the bell housing). Make sure that that bearing is not the "stepped" version of that bearing before you do anything else.

The stepped bearing isn't available any where I could find it. It is possible to substitute the later (normal) bearing style. The stepped bearing has two different exterior circumference. The exterior size steps from smaller to larger diameter. That step prevents the bearing from falling or being pulled into the trans. from where it sits in its seat in the transmission case.

The newer (available) bearing uses a snap ring (in a groove encircling the bearing outer diameter.) That ring serves the purpose of preventing the bearing from drifting into the transmission cavity. That is the same purpose of the "step" in the old style bearing.

The problem is that the snap ring is too big around (circumference) to allow the cover to fit over the bearing. The cover is what you see when you look into the bell housing. The input shaft exits the transmission then passes through that cover and into the clutch disk.

That snap ring prevents the cover from seating / sealing on the transmission case. HOWEVER, you can grind down the snap ring around its outer diameter enough to allow the cover to clear it and seal to the case.

[SubGothius]

I wonder if there might be a newer cover design that goes with the newer bearing design, so you could just swap the bearing and cover together?

[FMS88]

Suprabrew, Thanks for your counsel and explanation of the stepped bearing issue. Trimming the snap ring seems like a sound workaround and a necessary one if stepped bearings are no longer available. When my trans started getting noisy, all the shops I checked said it was the input bearing and that getting to it required a complete teardown. If that's not true, either they a) assumed it had the stepped bearing, b) were trying to maximize my cost and their revenue, c) were in total CYA mode, or d) all of the above (my choice). The one I chose had good reviews, but I had to take it back five times (the last for another teardown) before they got it right. Wish I'd never set foot in the place.

[Suprabrew]

I tried to find that same exact answer for the question, "MUST the tranny be opened to replace the input bearing?" before I did anything. I was told, "Yes it does". After rebuilding two of those trannys I can't give you a confirmed "yes" or "no". I opened the trannys anyway so I didn't concern myself with any work-arounds.

That bearing MUST be removed through/from the outside of the tranny bellhousing before the shaft can be removed. The question is, "Can the replacement bearing be installed ALSO from the outside of the tranny. And I have ran this scenario of my answer to you the past two days because I figured this question would come up.

I doubt very much there is an aftermarket cover designed to accommodate the 'wrong' bearing.

Bummer with the tranny rebuilder. I went through a similar experience in NC when having my auto trans rebuilt in my '93 Dodge van. What a freakin' nightmare. I eventually had to have the police meet me at the fellow's shop for my own safety to pick up the van after second rebuild. When I left and drove down the road a short distance, I checked the fluid level and it was EMPTY! He came to me and filled the tranny and acted like he was going to kick my ass when I suggested he intentionally left the level so low.

First, the bearing being stepped or otherwise doesn't make any difference when removing / replacing that bearing. It only seems to affect whether the input bearing cover will clear the bearing when installed and allow that cover to seat to the tranny case.

What I have decided is that if you attempt to install a new bearing WITHOUT opening the tranny, remove the bottom drain cover (stamped steel which included the drain plug). This will might give you access to the input shaft by reaching inside the tranny and supporting the input shaft while you drift/tap the new bearing onto the shaft from the bell housing side. Ideally you would wedge something or have someone giving support to the interior end of that shaft while you drift the new bearing onto the shaft from its exterior end. The input shaft meshes against another shaft inside the tranny and you don't want hard hammering on the exterior end of the shaft to damage the mating internal gears.

[FMS88]

This is great information. Thanks! If or when I get one to rebuild, I'll be sure to try removing the input bearing first to verify it's feasible. However, I agree drifting a replacement bearing into place seems challenging and a risk to other internal parts. Plus, if the new bearing or its installation affects internal tolerances, how can you check and compensate for any needed adjustments? If drifting the bearing isn't feasible or wise and you want everything spot on, a teardown seems the best route. Hopefully, I'll be able to find out first hand sometime soon.
Lastly, my other tranny lament has been with the pilot bearing in the flywheel. I've had two seize, each time wearing a wide groove near the front tip of the input shaft; can't be good for the input bearing. Use a plastic/rubber sealed bearing. The metal shielded bearing the tranny shop installed seized after less than 30k miles.

[geezer101]

I had a driveshaft rebuilt by a shop. The carrier bearing had to be pressed on and off and I ran into a problem. The carrier bearing I bought was listed for the Mitsubishi Gen 1 truck but the dust seal that was on the shaft didn't fit the bearing profile so the shop pressed it off. As a foot note to anyone getting their driveshaft overhauled, some of the early ones had the uni joints staked in place. They are almost impossible to rebuild. If you run into this scenario you'd be better off getting the driveshaft fitted with circlips on the uni joints and rebuilding/installing that instead.

FMS88, that was bad luck your pilot bearings both got cooked in such a short amount of time

[Suprabrew]

FMS88: internal tolerances? I don't need no stinkn' internal tolerances! LOL. Seriously, I didn't do any kind of precise tolerance checking when rebuilding and it all worked out (twice) except for the final torque on the final mainshaft nut I wrote about earlier. My torque wrench wouldn't fit the application so I used the 'seat of my pants'. Turns out that pants aren't a very good torque wrench. A bummer about the pilot bearing. Probably damaged when stabbing the shaft into the clutch/flywheel or the input shaft is bent (doubtful). When I pulled the original clutch (at 150 K miles) the piiot was nothing but a little strip of scrap metal but no indication of problem was noticeable when driving.

Also, I was thinking that the input bearing cover for the later transmissions would have clearance for the snap ring since that is the factory application and the bolt pattern to seat the cover to the bell housing is probably the same. 'So if you can get a newer style bearing cover, it will probably eliminate the need to grind down the snap ring outside diameter to fit the older style bearing cover. THs whole 'stepped bearing' problem will probably never occur anyway...Happy Thanksgiving

[solartony]

the seals of my driveshaft center/middle support bearing are all dried up & crumbly, both sides ...
the bearing itself, u-joints, seem to be all good, no wobbling or noise while driving ...
the auto parts shops have the full assembly ...
https://www.autozone.com/drivetrain/...b14/228611_0_0 ...
how easy is to replace it & how to go about it ? ... does the entire driveshaft need to come out, from transmission to differential ? ...
seals on transmission & differential look good ...

[FMS88]

You do need to remove the entire driveshaft. Be sure to make mating marks on the shaft flange yoke and the differential flange. Helpful or necessary tools are: snap ring pliers, a vice, bearing puller, large socket and breaker bar to remove the lock nut, and a torque wrench. Follow the steps above in Post #2. Be sure to mark the u-joint caps and yokes so they will be reinstalled in their original locations. Also install the u-joint so the grease fitting points to the rear and is in the same relative position as the rear joint. This keeps the shaft in phase and with alignment of all the marks, ensures the shaft stays in balance.
Of note, if you don't need to replace the u-joint, you can remove only the joint caps in the center yoke. That'll simplify things and keep the center and rear joints aligned.
The above applies to a Gen2 truck. If you have a Gen1, there may be differences (see Post #12 above). If there are differences not mentioned above, hopefully a Gen1 owner will add them to this thread. Have fun.