Replacing pinion bearings on 8.5 diff

Discussion in 'Got gears?' started by Dr. Roger, Jan 25, 2019.

  1. monzaz

    monzaz Jim

    Whine noise is usually a gear issue and whirl sound is normally a bearing pinion etc.

    if you shift the cars weight hard in a turn and accelerate NOT A BURN out...lol. the side the car is leaning towards creates a growl or crunching noise look toward the axle bearing your leaning on...
    carrier could cause a WHINE of the gear as it will tip the ring in and out of load (IF it is real worn) again a whirl type noise or a bit crunchy at a slower speed just before stopping and starting with load if it has some good size pits galling etc. REMEMBER this is a guide... sometimes things just are bad and make different noises because of oil heat load etc. and be something totally different...
    Just trying to give some guidance the best we can that we have noticed over the years..

    Jim Mitschke
    J D Race
     
  2. yachtsmanbill

    yachtsmanbill Well-Known Member

    Yachtsmanbill.
    IF that's a pic of one of your rears it appears the brake shoes are on BACKWARDS!!!!

    Seriously? Not even looking at the book, I was always taught that "all the junk goes into the trunk", meaning all the hardware is to the rear EXCEPT the E-brake which has a shorter lining. Hmmm. Actually, when they were apart for service, I just replaced them the way they came off not even paying attention. Those are the shoes that came installed from the PO...

    Off point but the answer is yes, thats a Type "O" Olds rear end. Dont ever be surprised what youll find under something 46 years old... Look at Joan Rivers LOL... well maybe 20 years ago! ws
     
  3. monzaz

    monzaz Jim

    All your arms and parking brakes are on correct they are just on the wrong shoe. :)
    Trust me you are not the only one in the world.... We have had cars come in with 2 big on one side and 2 small on the other and they are wondering why there brakes were hanging up on one side etc too. LOL. No biggie.. just have to swap the shoes front to back that is all.
    Jim
     
  4. yachtsmanbill

    yachtsmanbill Well-Known Member

    So all the junk DOES go into the trunk? The longer shoes go on the rear? ws
     
  5. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    The Primary shoe (shorter lining) goes towards the front, so yes.
     
  6. Dr. Roger

    Dr. Roger Stock enthusiast

    So I went through the differential and couldn't find anything wrong and everything was in spec. Pinion bearings and carrier bearings are all fine. Teeth pattern on pinion-ring was good, backlash was 0.005, pinion preload was 10-12 inch lbs. As far as the rear wheel bearings, they seem fine as well (reversed brake drum puller method worked good getting the axles out... thanks for the advice). Since wheel bearings are sealed, its hard to tell, but they aren't obviously bad and seem pretty smooth when you turn them. I did find one of the u-joints was really tight, so I replaced that with one that moves more freely. The spider gears rattle a lot when you spin them or spin the tires, but the teeth look good. Could a worn pinion shaft on the spider gears or worn gears cause a noisy rear (straight-on, not turning)? Maybe rattling spider gears is normal. Guess I should also check my brake shoes. :rolleyes:
     
  7. monzaz

    monzaz Jim

    1f you have a 1970 - 197 6 GM A-body BOP rear with bolt in axles you can not have SEALED bearings...your bearings are oiled. The seal is out board the bearing so they get oil.

    Unless you are working on something else you have not showed us?? Maybe?

    Also Spider gears If open differential NON POSI.. check to see if the thrust washers are behind all the gears. If you are missing just one that will cause alot of backlash and noise.
     
  8. Dr. Roger

    Dr. Roger Stock enthusiast

    Bearings aren't sealed, but have washers on both side that keep me from looking at the needles. I checked all the spider gears and they all have washers. It's a non-posi. Maybe my noise was that half-bound U-joint.
     
  9. BUICKRAT

    BUICKRAT Got any treats?

    Ha ha, don't feel bad Bill, you got caught out on the oldest one in the book, and we deserve to have some fun with it.:D I did that once(or thrice), and my boss spoofed me for like 2 years yelling "Hey Steve, you put the shoes on backwards" !
     
  10. monzaz

    monzaz Jim

    Yep, Lets hope that is it as your not finding anything else...:( Kind of getting annoying when you go through most everything and nothing stick s out as an AH HA moment.
     
  11. yachtsmanbill

    yachtsmanbill Well-Known Member

    Ha ha, don't feel bad Bill, you got caught out on the oldest one in the book, and we deserve to have some fun with it

    LOL... No harm done. I really shouldve known better. As I said, thats the way they came from the PO, and working somewhat in the dark (under the car and the worst corner of the shop) it doesnt surprise me at all. Some things ya take for granted! The worst part is thatI was in there for the second time and didnt catch it before! Hers the other side; I never looked at this pic before so its a surprise to me as well! ws

    Batting 500 anyways! :eek:

    z7.jpg

    z8.jpg
     
  12. monzaz

    monzaz Jim

    that side is correct. :) Funny.
     

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