Finally rebuilding my 7.5

[onebadasscutlass]

I don't have that tool but I'm sure my brother-in-law has it, when the ring and pinion get here. I'm gonna go over there and learn how to do it

 

[Bonnewagon]

Good. That's another lost art and is a very valuable skill to know. I have a GM dealership Kent-Moore tool but there are less expensive ones out there. It's more than the tool though, it's the concept. Every GM factory manual has the procedure and it will give you a headache the first time you read up on it. But once you understand the concept, you can then do the job with confidence. So read up on it first, then let your brother-in-law walk you through it.

 

[pontiacgp]

Looking good! Do you have a pinion depth setting tool? If not, see what shim was under the pinion gear bearings on both the old and new. I'll bet they are close if not the same, and you can use that as a starting point. Then you can use a new crush sleeve and set the pre-load on the pinion gear and be pretty sure you are good to go unless a tooth contact pattern test indicates otherwise.

your right, we swapped out lots of gears and the pinion shim was always right on.....believe it or not the machined castings were very precise

 

[onebadasscutlass]

Will do some reading on it, I seen people do it before but never really got walked through it

 

[Bonnewagon]

Again, it's the concept. The gears are held in tension by pre-load so that the drive train turning torque doesn't affect their relationship. They MUST remain in their perspective spaces with no deviation, otherwise they won't mesh properly and they wear fast, make noise, or just outright break. Steve I figured out why. The pinion bearing race bed is easily machined from either end and tolerances can be tight. Not so with the ring gear bearing race beds, you are working from outside the case and through the axle hole. So they got it in the ballpark and relied on the fat shims to correct for final fitment. I have a collection of factory ring gear shims and they are all over the map as far as thickness, but the pinion shim was always within a thousandth or two.

 

[onebadasscutlass]

Well I got my ring and pinion today from summit racing. And some one missed up cause I payed for a Richmond sportsman ring and pinion and received a Richmond excel ring and pinion. Lol it came in a Richmond sportsman box but when I pulled it out the Styrofoam was really dirty and was already opened. It looked like it sat on a bench for 2 years and had the excel p/n on the Styrofoam and it had excel stamped on the gear. So long story short I sent it back. Won't get another till next Monday

 

[olds307 and 403]

Personally I would go with a solid pinion spacer. They are stronger and don't have to worry about them not crushing.

 

[onebadasscutlass]

Where can you get that? I never heard of a solid one

 

[Bonnewagon]

I'm curious. Do you mean the crush collar that collapses as you set preload? With a solid spacer, how would you measure and set preload on the pinion bearings? More importantly, how would you measure what size spacer you need?

 

[olds307 and 403]

I measured my existing pinion depth and matched it with the shims that come with the solid spacer when I did my gear swap. You can use the special holding tool and an inch pound torque wrench. I used an impact and set it where it had no slop but no resistance turning it.