Gm 7.5 setup

[Drkuhar]

did you replaced the bearing and races when you changed the seal?......

No i didnt just pulled the yoke, swapped the seal, put silicone on the splines and reinstalled the yoke . I know its not done correctly. I want to do this next one right before its put in the car

 

[64nailhead]

I am running a 26.5 tire 255/60r15 with 3.42 now . Im at around 2800 rpm at 55. I dont think there would be that much change at 3.73 and since i seldom leave the small towns around me it probably wouldnt matter. Just wondered if it would be a noticible change or negligible between the two ratio's.
Im also looking for tips/tricks to set up this new rearend. Should i used the spacers in it now to start dialing in the gear mesh etc

There is no trick or shortcut to setting up a GM 6.5, 7.5, 7.625, 8.2, 8.5 or Ford 7.5, 8,.8 rear loading differential. You need a couple of tools that aren't used everyday - caliper accurate .001", magnetic base dial indicator, standard torque wrench, spring torque wrench or rotational torque wrench - and PATIENCE.

FWIW, if your current gear wear is good then I'd recommend fixing repeating leak via a bearing/bearing kit replacement.

 

[83MonteCarloSS]

so after my weighing my options of a 9" or another 7.5 i decided for my use it would be more feasible to rebuild another 7.5 and i found a nice low mile one for 50.00 but has 2.29 gears. I saw quick performance offer complete 10 bolt packages with a posi carrier, gears and bearings for 495.00. Would there be a noticible upgrade to go to the 3.73 over 3.42 (which i have in my current rearend). They are the same price and I would have to change the speedometer gear. I mostly cruise around town, take kids to school, no drag racing or anything maybe occasional burnout at a stop sign with a mostly stock 350 engine and th350 transmission. Is there any tips on building a 7.5 anyone wants to share.

I would not advise switching from 3.42 to 3.73. I did with mine years ago and would have switched back if I didn't swap the trans to a 200-4R. I even thought about going back to 3.42 with the 200-4R but I don't want to mess with the speedo gear.
I didn't want to drive more than half an hour on the highway with the 3.73 gear. In town wasn't bad, but it always felt like I was missing a gear in the trans. Needed OD to make it work well.
Posi is definitely a good add!

 

[Bonnewagon]

No i didnt just pulled the yoke, swapped the seal, put silicone on the splines and reinstalled the yoke

There may be seal-worn groove on the companion flange. A new seal will leak if that is the case. A new flange is best but if you use a good epoxy like Marine Tex to fill the groove then polish it down flush it will work too.

 

[olds307 and 403]

I used the solid pinion spacer and shims. Anything that helps strengthen isn't a bad idea. Is there a sleeve or maybe time for a new yoke?

 

[Drkuhar]

There may be seal-worn groove on the companion flange. A new seal will leak if that is the case. A new flange is best but if you use a good epoxy like Marine Tex to fill the groove then polish it down flush it will work too.

I will look for that. After i get the new to me rearend rebuilt and swapped i want to go through the original and try to fix all the issues to be a good backup

 

[Drkuhar]

I used the solid pinion spacer and shims. Anything that helps strengthen isn't a bad idea. Is there a sleeve or maybe time for a new yoke?

How does the solid spacer and shim work compared to a crush sleeve. I've seen that mentioned but i am not familiar with it. I can do anything if i could see how its done once and i have every tool needed except a rotational torque wrench for the inch pound pinion nut setting

 

[olds307 and 403]

I measured my pinion depth before I removed it and used the solid spacer and shims to the same depth. I didn't like the idea of using a crush sleeve and making or buying a tool to hold the yoke. It did have my pinion nut back off twice, I used red loctite the second time. The Ratech smart sleeve is supposed to be the best of both worlds but never tried one.