1995 Blazer Differential Leak

Hey everyone,

I need help, 1995 Blazer, 2 Door, 4x4, 128000 miles (Rear Differential)

The other day I noticed a smell of burning oil near the rear of my blazer and noticed that gear oil was being sprayed near the pinion yoke. So I decided to replace the pinion seal.

I removed the drive shaft, pryed off the yoke and removed the old seal. The yoke has some wear from the old seal. (to me it doesn't seem to bad) so I replaced a new seal. With the yoke off the pinion moves around about 1/4 inch each way, which i think is normal. So I bolted the old yoke on, as hard as I could with my socket and wrench set, which the nut seemed to be back to the original spot. With the new seal replaced and old yoke on, the pinion does not move at all, which makes me think the bearing is not bad.

So with everything back together, I take her for a test drive and what do you know, the damn thing is leaking again, and not just a little, about the same as before. :banghead:

When installing the new seal I tryed using a pipe to get it to go in straight, it went in a little, one side first, but when conpletely in looked to be prefect.


If anyone could help me out I would appreciate it..........WHY IS IT STILL LEAKING

I have a low budget and don't want to take it to the shop!!!!!

Thanks, Tony

A couple of things come to mind - the seal could be in backwards, could have been damaged when put in, or if there is a groove on the part of the yoke where the seal rides it will leak.

I would say you need to replace the seal again and inspect the yoke for a groove when you have it off. And, you may want to invest in a seal driver.

Hey thanks for the feedback

Yeah their is a groove where the seal rides actually two, the seal is in the right way it could only go in one way, but yes I should drive it in evenly. Maybe I will buy a new yoke and install a new seal. :banghead:

Another thing, Is it possible to tell if the pinion bearing is bad with out disassembling the rear differential. If it was bad, couldn't you move the yoke and drive shaft around?

If anyone else has anything to help me out it would be great!!!

One last question, why would the yoke have wear on it from the old seal, what is the cause of that? :uhoh:



Thanks again, Tony

If the pinion bearing/s are bad, you'll know by observing a higher pitched whine while crusing at highway speeds, since it spins about 3 times faster than the axle shafts. If you remove the pinion from the diff. housing you may as well buy new axle and pinion bearings, and a new crush sleeve. A few things can cause a shaft to become grooved by a seal. The biggest culprit is usually grit/grime sanding the shaft down. Another possibility is lack of lubrication. A seal needs a little lube to stay cool and flexible. Smearing some lube on during assembly is a very good idea. Lastly, A poorly hardened shaft could cause a groove. I'd place money on the first or second, though.

Ok yeah, there is no high pitch noise from the rear, so then i don't think the bearing is bad. :grinyes:

Not sure what you meant by " I'd place money on the first or second, though."

I know how to remove the ring gear and pinion but that’s about it, I know nothing about how to set up a new pinion with bearings and the crush sleeve. I know that when you put it all together you use shims to adjust the gap between the pinion and ring gear, but only know about it (never have done it)

I think my best bet is to get a new yoke and pinion seal and see what happens.

Does anyone know if you can tighten the pinion nut too much or to little. Like I previously stated, I tightened the nut using a regular socket set as hard as I could, to where I thought was the original spot. I have heard something about tightening like 1/8 inch past the original spot.

Did I tighten it to much, or not enough, maybe I should have marked it first.


Anymore feedback would help a ton...........

Thanks again, Tony :popcorn:

By "placing money", I meant on my first guess or second guess of shaft grooving, sorry. I agree on the new yoke and seal. You can tighten the nut too much. It should take 10 In/Lb's to turn the yoke once the nut is properly tightened. Loosening it now should be avoided since the crush sleeve would have to be replaced.

Thanks again,

I hope i didn't tighten it to much, hopefully when i put the new yoke on everything will be alright. maybe, i will tighten it with my socket set, then see where it is at with a torque wrench.


Anymore feedback or opinions would be great from anyone!!!!!!!!!!!!!!!!!!!! :uhoh:


Tony

HAve another question, does replacing the old crush sleve change the gap inbetween the pinion gear and ring gear. Or can i take it apart, preplace the crush sleve, and put it back togther and the gears will still be aligned?

Tony :banghead:

The crush sleeve sets the pre-load on the pinion bearings, and it'a a one time use part. I've had a few occasions where the gears retained alignment after replacing all the bearings and the sleeve, so long as you put the shims back in their original location.

:icon16: Alright I replaced the seal again and everything is ok now, I guess maybe I put the seal in wrong. For all you first timers like I am, when replacing the Pinion Seal make sure you pound it in straight with a tube or seal driver. Also grease the back of the bearing. I learn the hard way i guess.

The yoke has taken the wear so far also.

corning_d3 thanks for all your help!!!!!!!!

Tony

Glad to hear your up and running!