Need quick help with 8 3/4 rebuild kit!!

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threewood

threewood

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I received my rebuild kit the other day and I believe I was sent the wrong washers. Please verify for me so I can contact the seller. I bought them from Diff-man on Ebay, if he is a member here, help would be appreciated. I'm taking the parts to a shop to set up the gears and just want to make sure I have everything I need.

My rear end is a 741 out of a 1962, the bearings/races all look fine. My issue is what I believe to be the adjusting washers that go under the rear pinion cone bearing and on the pinion face. Is this the correct name for these? My original is one washer, 1 3/8" i.d.. The stack I received with the rebuild kit measures 1 3/4" i.d., which would fit the 742.

I was thinking about it, are these shims thrust washers for the dif gears? I don't have my old unit out to see what size they are. Pinion adjusting washers should be included in a rebuild kit, yes?
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Their called pinion depth shims (or just pinion shims) and when you rebuild a differential you re-use what came out of it. Since their shims, not thrust washers, they don't wear or go bad. Their purpose is for setting the pinion depth and once pinion depth is determined there's no need to change it.

I do believe you got shims for a 742 case. Are the bearings correct? Their different on a 741 vs. a 742 case.

Cass is a super guy to deal with and if you'd like washers for your 741 I bet he'd have no issue sending them right out. Sounds like an honest mistake
 
fishy68 said:
Their called pinion depth shims (or just pinion shims) and when you rebuild a differential you re-use what came out of it. Since their shims, not thrust washers, they don't wear or go bad. Their purpose is for setting the pinion depth and once pinion depth is determined there's no need to change it.

I do believe you got shims for a 742 case. Are the bearings correct? Their different on a 741 vs. a 742 case.

Cass is a super guy to deal with and if you'd like washers for your 741 I bet he'd have no issue sending them right out. Sounds like an honest mistake
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Thanks! I measured the bearings and they are correct. I'm swapping out 2.76s for 3.23s so the original shim may or may not work. The one with the used oem 3.23 set measures .090 thick and I have yet to pull my 3rd member to see what size is installed. I sent him an email explaining the wrong shims, I just didn't want to use the incorrect nomenclature so as to not confuse the matter.

Mark
 
To me, those look like the same "washers" that are used to adjust ring-gear back-lash in diffs that do not have screw-adjusters, like the 8.75 has. The fat boys in there look to be too thick to be anything else.
 
.........R these new gears cause if no u r gonna have a gear whine that u may or may not b able to live with....the back lash on factory gears is prolly .030 and setting them up from where they were is big trouble.........kim....
 
Threewood
Its been my experience that the depth-washer should stay with the housing, rather than with the pinion.And always as a starting point.It seems to me that the pinions were machined far more accurately than the housings.I only use the depth-washer that came on the pinion if the housing Im working on is not accompanied by its shim.
 
AJ/FormS said:
Threewood
Its been my experience that the depth-washer should stay with the housing, rather than with the pinion.And always as a starting point.It seems to me that the pinions were machined far more accurately than the housings.I only use the depth-washer that came on the pinion if the housing Im working on is not accompanied by its shim.
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That is good to know, thanks. I got a response from the seller. The rebuild kits are put together by Motive so he called them and told them they shipped the wrong washers. They told him they were the same part lol and he told them otherwise. He said he found a set for the 741 and mailed them out. Makes me uncomfortable ordering anything from Motive.
 
oldkimmer said:
.........R these new gears cause if no u r gonna have a gear whine that u may or may not b able to live with....the back lash on factory gears is prolly .030 and setting them up from where they were is big trouble.........kim....
Click to expand...

My rear end guy recommended used gears over new gears. Didn't mention any problems and it is my only option for 3.23s in a 741 as they are not remanufactured. So are you saying all used gear sets will whine?
 
........No, I'm not saying all used gears are bad,but the earlier 1s had so much back lash that trying to set them to acceptable bl is nearly impossible without having a whine...good luck to ya.......kim.......
 
those shims look like they are meant to go under pinion bearing race, my 8.25 original rear had the big shims under race, you can put under race or pinion bearing same thing, the shims are just different sizes for where their used
 
Update: Picked up the 3rd member last week, got it installed today. Backlash in the old gears was .007, backlash in the new gears is .008

Drove it around and not getting any whine on accel or decel. My guy did a pretty decent job. Happy with the 3.23 gearing and the eaton trutrac!
 
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