I am at a loss to what’s going on ! I got all the stuff to convert my rear to a posi . Things were going well until we tried to set the pinion preload , can’t for the life of me get the rear pinion tight enough to even snug up the bearing we crank as hard as we can and there is still in and out play on the pinion . This isn’t a crush sleeve issue because we can’t get it tight enough to even engage the crush sleeve . I’ve tried two different pinions and the same results for both . It’s like the pinion shaft just stops advancing just short of snugging up the bearing . We’ve put this together on the bench several times and can’t figure out what’s stopping it .

 

Need more info.
Do you have the flange on the pinion?
Are you using a new nut or the old one? (new one should be very hard to tighten, old one should be looser).
Tried two different pinions? Two different pinion gears? You realize they are a matched set with the ring gear, right?
Maybe post pictures to help with what's going on.


This is no help to you at all, but why did you remove the pinion gear to do a carrier swap? I've done carrier swaps before and just shimmed the carrier side to side to get the backlash in spec without ever messing with the pinion gear. Now if you were doing a gear change or replacing bearings, I can see messing with the pinion preload.

 

ok let me try to be more clear i was on my phone earlier . i should have said tried two different yokes on my new pinion shaft (thinking the splines may have been bottoming out on my original one)what ive done is gutted my rear housing of the 272 gear ratio peg leg and am upgrading to moser axes, posi carrier and yes matching ring and pinion gears 3:23 ratio.we opened up the old bearings so they would slide on the pinion shaft easily and mocked everything up. it all worked well. now we begin to put it together using the new pinion shaft bearing i slide the yoke on the shaft and tighten with an impact wrench it goes on all but the last 1/8 of an inch and stops no amount of force can be used to get that pinion shaft to seat the final 1/8 inch of that bearing.the whole idea here is to seat the bearing, engage the crush sleeve just enough to get my preload ,by tightening the lock nut on the yoke.my good friend who has built dozens or rear ends says he normally holds the yoke with one hand and tightens the pinion nut with an impact wrench tiny amounts at a time until he gets the proper preload (too much and you start over with a new crush sleeve) but he's never encountered the issue im having.

 

OK, it makes more sense now.
Can you measure the bearing inside diameter and the pinion shaft diameter? Maybe there's a mismatch in dimensions there. If it went together with the "checking bearing" then it should go together with the final bearing.

 

Yes we took that measurement and the pinion shaft is .001 larger than the inside diameter of the bearing

 

What rear end are you even working on?
I am sure we can find out what is happening but everything needs to go step by step...And you will need to double check everything. Bearing part numbers etc. yoke to seal measurements...and so on.
But start with the rear type first. from your car list it looks like either a 7.5 or 8.5. I am sure your not doing the BEMMER rear
Jim
JD

 

So with the old bearings it works but when you switch to the new bearing no go.
Please check bearing number for outer pinion bearing.
Check to see if the yoke is bottoming out on the pinion seal - and check to see if the pinion spins when you have it tightened all the way as much as you can also.
What washer under the pinion nut are you using OLD or NEW?

 

correct jim no go with the new bearing .we have at least a quarter inch to go before we bottom out on the seal ,the pinion spins freely (when tightened as far as i dare to using 1/2 inch breaker bar and 4foot cheater) ,we are maybe 1/16 of in and out play when tightened. my original yoke had no washer on it so im using the one from my s10 yoke that i had.i will have to pry off the new seal to check the number on the bearing all the other bearings i got in the kit did have matching numbers and im pretty sure my buddy checked the pinion bearing too, but i will confirm tonight.thanks for responding

 

no not the beamer its the 1980 cutlass factory 7.5 rear. you sent me all the parts needed for the build .the package included all necessary bearings ,races seals etc.

 

Problem resolved ! Tried a new bearing ,same part number, installed everything exactly the same as previously with the exception of the pinion nut we opted for the original instead of the new one ,and it snugged right down until we crushed the sleeve just enough to get our pinion preload .It took a good amount of force tightening but not excessive.moved on to the carrier and set our backlash only took 2 tries on that .got a good signature with the marking paste ,installed axles and cover .Thank you Jim (Monzaz) for getting back to me and going over a bunch of questions i had .I now have a posi

 

So the inside race on the bearing was somehow out of spec?

 

Out of spec or out of round ? Really don’t know . But something about that bearing and that pinion shaft that didn’t like one another .

 

I have seen it once or twice before...But MAN that sucks.

WHAT a headache.

Jim