Front pinion seal, 98 Tahoe.

rockmafia

Well-Known Member
Joined
Apr 2, 2006
Location
sedalia nc
MIL's tahoe is leaking oil from the front pinion. Looks pretty easy to just take off the yoke, pry out the seal, put in new seal, put yoke back on.

Or is there more to it than this?
 
Make sure you measure the rotating torque before you remove the yoke, and when you go back together, be carefull not to go past that torque or you will have to take the whole thing apart and put a new crush sleeve in there. Measure the torque with the halfshafts removed. And get a new nut, sometimes the old one won't reach the right torque.
 
Measuring the pinion preload should be done with the carrier removed. Also the crush sleeve is a one time use item. But considering its a front diff and prolly rarely used (does your MIL go offroading?) I would try and just put a new seal and tighten it back down. Try putting a mark on the nut and yoke and put the nut back where it was (count the turns coming off) that should get you close enough for a front diff

Another thing, make sure its the pinion thats leaking, i see alot of oil pans/valves covers/oil pressure sensors leak down onto the front diff making it look like the pinion seal is leaking.
 
You can reuse those crush sleeves, I worked for a GM dealer for 7 years, I probably did 5-6 of these a week, and GM service information tells you to do it in the car. It's more trouble than it's worth to pull the whole carrier. But don't reuse the nut, that's a one time use deal.
 
Thats good to know, everytime i'vi hade reused one it came back and bite me. So i don't reuse them anymore

Do they let you reuse the crush sleeves in the front and rear? No doubt its faster that way (faster=cheaper=better for GM), no need to pull axles or carrier. Thanks for the info
 
Only in the front. The only time I've ever had a problem was when you try to reuse the nut. When your sure you cranked it all the way down, your wrong. I've seen the nuts come loose and eat up the gear set pretty quick. As long as you get the same rotating torque as before you start, you're ok. If you ever need GM service information, let me know, I still have access to all of it and it's better than Alldata or anything else out there.
 
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