[fondo]

Hi all, I'm new to the site and have a some questions re-guarding the replacement of the rear diff pinion seal on an 1993 oldsmobile bravada. 1)What does the nut need to be torqued to and do I need a new one.2)Do these rear ends have crush sleeves and if so do I need to replace it if I'm just doing the seal job. 3)What special tools do I needs. 4)More specifically, when do I need to measure the torque specs and in what sequence. This is my first rear end r&r so I'm kinda unsure at the moment and would like to take all the extra precautions necessary as I'm aware of all the things that might go wrong if overlook something. I do have a chilton manual but the section(s) outlining this particular area are kinda general and vague so I would appreciate any help. Also I did search and found a 96 bravada diff service fsm, I was wondering if this is the same as a 93?
Thanks again and sorry for a lengthy first post.

 

[nailhead425]

Hi all, I'm new to the site and have a some questions re-guarding the replacement of the rear diff pinion seal on an 1993 oldsmobile bravada. 1)What does the nut need to be torqued to and do I need a new one.2)Do these rear ends have crush sleeves and if so do I need to replace it if I'm just doing the seal job. 3)What special tools do I needs. 4)More specifically, when do I need to measure the torque specs and in what sequence. This is my first rear end r&r so I'm kinda unsure at the moment and would like to take all the extra precautions necessary as I'm aware of all the things that might go wrong if overlook something. I do have a chilton manual but the section(s) outlining this particular area are kinda general and vague so I would appreciate any help. Also I did search and found a 96 bravada diff service fsm, I was wondering if this is the same as a 93?
Thanks again and sorry for a lengthy first post.

You'll need:
1) a torque wrench that reads in inch-pounds

Yes they use a crush sleeve, if you don't change anything you won't need to replace it. Tighten the pinion nut until there is 15-25 inch-pounds to rotate the pinion gear. (closer to 15 with old bearings, 25 with new)

In a HP application you can use shims to eliminate the crush sleeve.

 

[fondo]

Hey thanks for the speedy reply. I have one more question though, do I need to put the vehicle on stands when I measure the torque (before and after replacing seal)? The chilton manual doesn't say so. Can you elaborate on this a little more for me?
Thanks again...

 

[nailhead425]

Hey thanks for the speedy reply. I have one more question though, do I need to put the vehicle on stands when I measure the torque (before and after replacing seal)? The chilton manual doesn't say so. Can you elaborate on this a little more for me?
Thanks again...

Yup. I'd even go so far as to remove the brake drag as well. It doesn't take much to get that in-lbs rating, fyi. Just remember to tighten it until it takes that much torque to turn the pinion gear, so the torque on the nut will be more.

 

[fondo]

Hey thanks again for all the useful info. So is that all the torque the nut needs to stay put? That doesn't seem like a whole lot to keep it in place. Nineteen inch lbs. is what I measured when I turned the pinion. Does it tighten more as you drive down the road? Sorry to be a pest, I just wanna get it right. Thanks again...

 

[fondo]

Ok, now I understand what I'am doing. I was confusing myself but now I think I get it. It takes so much torque to push the flange back on the pinion shaft but after that you need the "measured amount" to turn the pinion assembly in order for the preload to be correct, right Any how it only took about 14" lbs. to turn the pinion. Will that do?

 

[nailhead425]

Ok, now I understand what I'am doing. I was confusing myself but now I think I get it. It takes so much torque to push the flange back on the pinion shaft but after that you need the "measured amount" to turn the pinion assembly in order for the preload to be correct, right Any how it only took about 14" lbs. to turn the pinion. Will that do?

Bingo.

14in-lbs is really close, but if you have lots of miles, I'm sure it will be okay.
If you hear any noises on acceleration or coast, recheck it.

 

[fondo]

120,000 miles, most of that in Lubbock, TX (very hot/dry), had some abuse/negligence (not me) for a period of time. So, given that, I would say my measurement is close enough if thats what you'd consider "high mileage".
Any how, thanks for all of your input... much appreciated!!

 

[bouda]

You'll need:
1) a torque wrench that reads in inch-pounds

Yes they use a crush sleeve, if you don't change anything you won't need to replace it. Tighten the pinion nut until there is 15-25 inch-pounds to rotate the pinion gear. (closer to 15 with old bearings, 25 with new)

In a HP application you can use shims to eliminate the crush sleeve.

Is'nt that measured with everything removed from the axle housing so that you are only rotating the pinion gear?

 

[Johnny P]

Is'nt that measured with everything removed from the axle housing so that you are only rotating the pinion gear?

Generally, but you'll find that it makes very little difference(if any) on the readings with the diff. fully assembled. If it had drum brakes and and they are correctly adjusted I wouldn't even remove the drums.