Differential Bearings?

[bmiszuk]

I have been chasing a noise for several months now and think I've narrowed it down to the carrier bearing(s) in the rear diff. It's a grinding noise that starts somewhere above 20mph and is most apparent between 20-35mph but can be heard at other speeds also. At first I thought it was front wheel bearings but the bearings are new and the noise still there. The noise changes with road speed but does not change if I put it into neutral. It sounds like it's coming from front left, but maybe that's just because I'm sitting in the drivers seat.

From what I read, this is typical of carrier bearing failure. The tranny and transfer case were recently rebuilt so I doubt the trouble is there. U-joints are all new, front wheel bearings are new.

1. Any other places I should check before tearing into the diff? I'm planning on simply replacing all the bearings, not the R&P.
2. Am I correct to assume that I have a 10-bolt 8.5" diff?
3. If I'm just replacing bearings, is there a good chance I can simply reuse the shims that were in there? I will check the pattern, of course, but am hopeful for an easy setup.

Thanks.

Bob

[darkroad]

Hi Most of the time if you are replacing the bearings and not installing a new ring gear set just use the shims that were in there. Be sure and not skimp, use only timkin bearings. Some rebuild kits are not timken , most that are let you know that timken is what you are getting. Just rebuilt my wifes 1992 suburban rear end last rear. Bought the complete rebuild kit. Wheel bearings and seals, carrier bearings and pinion bearings. I did have to check my clearances since I was also installing a new posi unit but luckly I didnt have to change anything. Good pattern and backlash right in the middle of specs.

Good Luck


Darkroad

[Robyn]

As long as you keep the shims where they came from you will be fine.

The bearings are not all that fussy, Timken, Bowers and many others are just fine. As long as the numbers are the same

Koyo makes fine bearings to
If you do the carrier Brgs do the pinion too.
If the one set is chewed up and making noise the others have had plenty of junk go through them and loads of time and miles.
Do them all and wash the housing out well to get rid of all the old crud.
As long as you keep all the shims where they came from you can put it back together and bolt everything up and your good to go.

When you start swapping gears and such is when you get into fooling with backlash and patterns and such.

Secret *****
When pulling the bearings, Cover the spider gears and the carrier up good with a towel.
Then cut the bearing cage with side cutters and peel the cage and rollers off the inner race.

Now use a die grinder and a cutoff wheel and grind a little slit through the inner race on a slight angle so you dont hit the carrier.
Once you get most of the way through use an old junk chissel and place it in the groove you have cut.
Smack the chissel with a nice sized club and the bearing will break along the cut line and you can pull it and the shims off without needing a fancy puller or a press.

Do both sides this way and then clean everything up.
Now you can place the shims back on one side and replace the bearing..

Warming the bearing with a propane torch until its hot enough that you cant hold it ( Now dont fry the little beast but get it good and hot)

The hub needs to be clean, smooth and just a little neverseaze on it.
The hot bearing should slide on easily and once there place a suitable intrument over the inner race and smack with the big club to seat the bearing solid against the shims and the journal.

Repeat on the other side.

The pinion can be done the same way.
The spacer in the center that sets the pinion preload can be reused as GM does not use a CRUSH sleave on these units.

Tighten the nut down with an impact wrench until tight.
If you dont have a new locknut use Blue loctite on the threads.

The pinion should rotate with a little drag, not too tight and not loose just a little drag.

The books will give you and Inch pound reading as to what it should take to turn it.
Just right is my term.

Be sure to lube all bearings with 85 W 140 gear oil before assembly.

While you have the axles out I would look the axle bearings over good to make sure they are not going south too.
The bearings in a 10 bolt run directly on the axle. Be sure there is no sheel out or brinelling on the axle where the bearing runs. (Rough like a washboard road)

If you find any undesirable stuff on the axle, dont even put it back in and do replace the bearing too along with the axle shaft.

Take a good look at the C lock groove in the end of the axle and make sure things are hunky there too.
The C lock should not have a lot of slop in the groove.

Be sure to use a little Blue loctite on the bolt that holds the center pin in the housing.

Do this and your good to go.

Hope this helps

Robyn
Do replace the seals at the axle bearing