My 1028 A1 had it's first failure in two years

[corvette9]

My 1028 has been flawless up till now. I bought this truck from Cucvrus. I must say he maintains these trucks great. Every system in this truck worked perfect when I got.it.
A few days ago I could hear a strange noise coming from the rear of the truck. It sounded like a brake shoe fell apart. After alittle test driving I found that the noise was only present on deceleration and would go away with acceleration. Right then I knew it was a problem in the rear. I thought it was the pinion bearing. I pulled the cover today and found I was right.
Soooo. I'm going to replace the bearings. I just ordered all parts needed from NAPA.I also drained the front diff and the transfer case. While it's on the lift I figured I should change those fluids as well. You can see the bad bearing in the pics.

 

[Chaski]

A 14 bolt isn't totally indestructible. I experienced pinion bearing failure on my rig, seems like the pinion seals die, or contamination enters from somewhere else then the fate is sealed. It is nice that the entire pinion assembly unbolts and can be removed so that all the work is done on a bench. If you don't have an inch pound dial type torque wrench, a clamshell bearing puller, a hydraulic press, and a giant breaker bar on hand you should beg, borrow, or steal them before starting.

 

[motorstormer]

Quick and probably dumb question but should the pinion have any play or is that a sign of a bad bearing?

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[Chaski]

Pinion should have no play. If it does who knows what it is doing to your gear pattern and will lead to mulching your ring and pinion.

 

[motorstormer]

That's what I was thinking but never dealt with axells this heavy before.

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[dmetalmiki]

I like the way you diagnosed the problem and hauled off road before more damage ensued. Merritt points.

 

[corvette9]

After doing some research.There are a lot of diff. 14 bolt GM rears. It looks the axles in these CUCVs where only made 84- 87. The pinion assy pulls rite out as an assy. Just the 6 bolts in the flange. That bearing in the pic is called a pilot bearing. Once the pinion assy is out I need the remove the bearing and install the new one. it is pressed into the housing.

It is much like a pilot bearing for a 4 speed stick trans. looks very simple. I hope.

 

[Chaski]

If the pilot bearing is bad I'd say you have a 98% chance your other two pinion bearings are also bad. It is more complex to replace those. Is there any play in your pinion? The only difference in the 14 bolts is the race for one of the pinion bearings was a different size depending on if it was an early or late style.

 

[corvette9]

If the pilot bearing is bad I'd say you have a 98% chance your other two pinion bearings are also bad. It is more complex to replace those. Is there any play in your pinion? The only difference in the 14 bolts is the race for one of the pinion bearings was a different size depending on if it was an early or late style.

No play in the pinion. The think because the pilot bearing did not disintegrate it is still holding the pinion in place. you can see in the photo only a few rollers are missing. If I had not checked it as soon as I heard the noise it would have caused more damage. Lets hope im right.
I hope to pull it apart in the next few days.

 

[Chaski]

http://www.pirate4x4.com/tech/billavista/PR-ARB/articles/14b_Gear_Setup/

A good article to look at for setup if you need to do it. I'm curious if you pinion has any preload left, or if the other bearings are worn enough that you have 0 preload.

 

[Skinny]

You won't see any pinion play with that bearing failure because the main tapered bearings are held in the removable support plate. That little guy that got munched is just there for extra support to minimize deflection under load. Good catch! Lucky it didn't do any more damage. You can replace that one bearing with almost no special equipment. Just pull the pinion assembly out and swap it out. The other pinion bearings are alot more involved than that.

 

[corvette9]

I did exactly that. Very simple fix. All done. Now I'm going to replace both u joints and go back to driving him. The truck has a name that CUCVRUS gave it. It's Dude.