Pinion Seal Replacement

BBslider001

Diesel Head
Well, I'll be replacing the seal this weekend along with doing the front brakes. I have been wondering if there is anything I need to be on the lookout for when doing this? I have a good impact, Medium Strength Loctite for replacing u-joint bolts, and good mechanical skills, but have never done it. I have read that you have to be careful about crushing the sleeve? Anybody done this one? Larry? Thanks!
 

SixLug

Explorer
I'll be watching this. I have a 94 K5 Blazer I just picked up that needs the seal replaced. Bought one, but haven't messed with it yet. Looking through the haynes manual, it seams easy enough.

Take notes on how it goes!
 
Last edited:

Ageless Stranger

New member
It's not a difficult job. I've done the front axle on my TJ once already, and it needs it again now. The worst thing for me was trying to make sure that the pinion nut was torqued just right due to the fact that the D30 has a crush sleeve in it. Don't know about your axle. Changing the seal itself is quite easy. :)
 

Larry

Bigassgas Explorer
Front pinion seal or rear? Funny, as the rear 14 bolt full-floater I just installed in the Polar Bear Burb last month started leaking a few weeks ago.

For the rear, take note of the distance from the yoke splash shield is in relation to the pinion housing so you know how deep (or how much to tighten the pinion nut) to put the yoke back on after the seal replacement. I used a steering wheel puller to pull the yoke off of the pinion then used a hammer and chisel to tap the old seal off. The lip of the seal on these 14 bolt FF axles stick out past the pinion housing so there is some good meat to beat on in order to get the seal out. Tap the new seal in then tap the yoke back on the pinion. It is not a bad idea to add sealant to the pinion splines to prevent leaks between the yoke spline and pinion spline. It was a quick easy deal, less than a 30 minute but these seal was dejapoo as I've seen this ******** before.

The front is not much different. In fact, the front pinion seal I recently replaced on our 2004 Tahoe was even easier.
 

braap736

Observer
Make a mark on the threads and nut in one spot before takeing it off, then run the nut back on until your mark lines up so you have the same amount of pre-load as before. Im no tsure on that axle but if the pinion shaft sticks out past the housing it makes it difficult to press the new seal in evenly. I found a cup (not a glass one) that had the same diameter of the seal and used that with a light tap of a hammer to press it in.
 

BBslider001

Diesel Head
Thanks for the input fellas. I'll let ya know what happens. I keep reading not to overload the pinon set, so I'll be watching closely for that. I may not even get to this until next weekend. Swell is coming and I need water time in a desperate way!
 
Last edited:

BBslider001

Diesel Head
Well, got some water time....all is well with my soul. :sombrero:

So, I go to check my vent on the rear diff today and find a plug in it! Is that normal? I thought this thing was supposed to be able to breathe? The vent tube looks like it is where it supposed to be from stock placement, but there was a plastic plug in it to hold one of the hoses to the driver side airbag. What??!! I took it off and put it in a ziploc to save it.
 

shortbus4x4

Expedition Leader
The plastic thingy in the end of your breather line should be there to keep crud out. It will let your diff vent but not let stuff in.

Is your pinion bearing preload set with a crush sleeve or shims? What size diff you doing a pinon seal on?
 

BBslider001

Diesel Head
Front pinion seal or rear? Funny, as the rear 14 bolt full-floater I just installed in the Polar Bear Burb last month started leaking a few weeks ago.

For the rear, take note of the distance from the yoke splash shield is in relation to the pinion housing so you know how deep (or how much to tighten the pinion nut) to put the yoke back on after the seal replacement. I used a steering wheel puller to pull the yoke off of the pinion then used a hammer and chisel to tap the old seal off. The lip of the seal on these 14 bolt FF axles stick out past the pinion housing so there is some good meat to beat on in order to get the seal out. Tap the new seal in then tap the yoke back on the pinion. It is not a bad idea to add sealant to the pinion splines to prevent leaks between the yoke spline and pinion spline. It was a quick easy deal, less than a 30 minute but these seal was dejapoo as I’ve seen this ******** before.

The front is not much different. In fact, the front pinion seal I recently replaced on our 2004 Tahoe was even easier.

Sorry Larry...it's the rear. I am waiting to see if unpluggung the vent tube will alleviate the leak that has been happening.
 

BBslider001

Diesel Head
The plastic thingy in the end of your breather line should be there to keep crud out. It will let your diff vent but not let stuff in.

Is your pinion bearing preload set with a crush sleeve or shims? What size diff you doing a pinon seal on?

I believe it is set with a crush sleeve from what I have read. I haven't had it apart yet. I have the FF 14 Bolt. The plastic plug looks just like that...a plug. I don't see ho it could let it vent. It was hard as heck to pull out. I can always put it back. The vent tube itself is set pretty high above the rear wheel and attached to the frame.

I'll be tackling it next weekend along with the front brakes. Good times, but glad to do it. I have an impact, good jack-stands, and a 5 ton floor jack. It makes things much easier.
 

BBslider001

Diesel Head
Might start by checking the vent tube...pull it off and make sure you can get air through it. If it is clogged pressure can build up in the diff and push oil out. The one on my f150 was clogged and didn't show itself till a couple of hours on the highway. Once it was cleaned it hasn't leaked since...

Some YouTube vids:

http://www.youtube.com/watch?v=HNkGdByzyjI[/u] [url]http://www.youtube.com/watch?v=pCy0Xdz6SNI

I am wondering if this same scenario has been making mine leak. That is why I pulled the plug thingy. We'll see. Thanks for the vids. I'll check them out!
 

SixLug

Explorer
So I did this replacement last weekend. What a pain to get the rusted-on yoke off. Anyway, it's STILL leaking, albeit a bit slower, but I put RTV on the splines too. Something else I read said not to drive the seal past the pinion nose...? (http://www.fullsizechevy.com/forum/...maintenance/488163-rear-pinion-seal-leak.html) but the Haynes manual I have says to seat the seal all the way...? I seated it all the way, cleaned the yoke before reinstallation, lubed the seal lip, etc. the yoke had a small groove but nothing insane, could just be felt with a fingernail.

I'm going to have to remove the driveshaft again when I replace the transmission soon but if you guys have any insight, please let me know.

Thanks.

(1994 K5 Blazer, stock)
 
Last edited:

BBslider001

Diesel Head
Well, better late than never I guess. I am just now getting to this today and the nut will not move by my strength alone. I left my impact at the shop, like an idiot. Guess this won't be happening, once again.
 

Forum statistics

Threads
185,841
Messages
2,878,760
Members
225,393
Latest member
jgrillz94
Top