Rear differential question

[brianm]

Greetings friends . I am Rebuilding the rear end in my firebird and I was wondering if a guy can reuse the crush sleeve for setup only ? Then install a new one for final assembly? I am down to my last one and I am close but iam not sure this will be the final time I need to reshim the pinion to get the gear pattern correct . I don’t see a problem with it but it’s my first total axle overhaul so I am not sure. Thanks for any help.

 

[JMCX]

For setup I've never bothered with it.

 

[brianm]

Kind of what I think to but I wasn’t sure. Thanks buddy!!

 

[Summitric]

What he said /\ /\ /\

 

[brianm]

Well gear guys does that look acceptable or does it need more adjustment?

 

[arff]

What is the backlash at ?

 

[brianm]

7 thousands. Gear instructions ask for 7-9

 

[arff]

7 thousands. Gear instructions ask for 7-9

That is great work.

 

[DRD]

Could stand to move to the root a bit more IMO...

 

[brianm]

Root ? Dumb it down for me . You mean further down on the ring gear towards the base ?

 

[brianm]

Never mind I got it figured. Thanks

 

[brianm]

Looks like I could move the pinion towards the ring gear a bit ? Adding shims to the pinion.

 

[Summitric]

definately need it a little deeper...

 

[brianm]

Ok . I have a 36 in there now probably try a 40 see what that looks like. Thanks for the help

 

[DRD]

 

[brianm]

I looked at a million of those gear charts and none ever match up to what I get . Looking at my pictures I would say I have more contact on the drive side at the toe and the coast side is towards heel . Would I not have to add pinion shims to get the gears more centred I.e drive side up and coast side down ?

 

[Cdnfireman]

I looked at a million of those gear charts and none ever match up to what I get . Looking at my pictures I would say I have more contact on the drive side at the toe and the coast side is towards heel . Would I not have to add pinion shims to get the gears more centred I.e drive side up and coast side down ?

That’s what I would do and then check your pattern again. Looks to me like your pinion is too shallow in those pics. Then re-check your backlash of course.

 

[JMCX]

The trouble is sometimes the shims are between the bearing and pinion and sometimes between the race and the housing. So depending on the diff you're dealing with, adding or subtracting shims has the opposite effect. Ford 9" are sure a breeze to play with.

 

[brianm]

I went to 40 and it looks good, bearing preload was at 20 inch pounds . Backlash was 8 thousand. Just got to check the the carrier preload and see what rat hole that leads me down lol. Yeah the gm 7.5 has the shims between the gear and bearing it’s not bad once you get you “ adaptors” to get the bearing on and off . I use the word adapter loosely lol.

 

[JMCX]

I always buy an extra bearing(s) for the ones that have to come on and off. I carefully oversize the ID so they slip on just by hand. I see now you can buy these 'setup' bearings.