Front Pinion Seal

[robriguez]

I have a 06 Envoy Denali 4x4.

I went to change the oil yesterday and not only did I find that the drain bolt was all hacked up and impossible to remove even with a large set of vise grips and a pipe (I will never let the wife take any of our cars to PepBoys again) but then I noticed there was some "wet" to the drivers side of the oil pan. So, I figured I would kill 2 birds and drop it off at the dealer today to see if they could get the plug out and replace it as well as see what the wet was. They came back to tell me that I need a front pinion seal and its going to cost me about $400. If thats not the problem then they have to change the gear box cover for $1500. Im just out of warranty (39k) so I'm looking for some answers to hopefully help me swallow the cost of this.

-Is this a common problem?
-Is this a DIY type job? I do all my own work on my motorcycle and all maint on my vehicles (brakes, fluid changes, even simple tune-ups and changed out suspension parts a few times on my older cars) but Im not a mechanic by trade.
-Ive never seen a drop of fluid on the driveway so Im assuming this is not a bad leak. What if I just change the fluid often and keep it topped off? I know its not the solution but $1500 is a VERY huge pill to swallow for me right now.

your suggestions please....

[greggf]

would that not be covered under powertrain ,60,000 or 5 years..or i am i thinking wrong

[Robert1101]

As far as my vehicles, if the leak is very small, and adding a little gear oil once a year or so, it would be ok. There are a lot of if's there. It is your call, but that is a lot of labor costs.

[Gearhead2012]

400 seems like a lot to change a pinion seal, even on these things. I'm sure you've seen, or read, that the differential is bolted to the oil pan, in 2 halves, and therefor makes jobs like that even more of a PITA. To change the pinion seal, you'd remove the front driveshaft, and loosen the pinion nut...doing so, will change the preload you're gears have on them from the factory. There's a crush sleeve under the bearing to properly hold the proper pinion load. If you loosen the pinion nut, you're supposed to change the crush sleeve as well.

Could you get away with not replacing the crush sleeve? Probably, and as long as you don't live somewhere where you use 4wd a lot, especially at higher speeds (like in the ice) you'd probably be ok...as long as you got the pinion nut torqued back down just right. 400 dollars is sort of a lot...but only sort of. You could probably take it to a competant mechanic and have it done easily for half of that...as long as they were familiar with the process...(read - not merchants).

The drivers side cv shaft seal is famous for leaking on these trucks as well...mine does. make sure it's not that. Take a can of brake clean and spray underneath really good, and take it to the store and back, and see where the leak is coming from for yourself. If it's the pinion seal, I'd say let someone who has experiance doing so take care of it...if it's the cv shaft seal, you can do it. If it's the gear box cover, that really is a pain in the ***. You'd have to drop the oil pan, and all sorts of crap if I'm not mistakin. I looked into dropping the diff. when I lost 4wd...and it was listed as like a 15 hour job...so, I'm sure that changing the cover gasket isn't too far off from that. Good luck.

[Gearhead2012]

P.S.: You also might just wanna try adding some gear oil to it, along with say a lucas (or similar) oil additive, and see if it slows down, or stops the leak. Might be as simple as that.