I need your help guys. i noticed while walking to my truck that the bottom of my rear diff was wet and there was some drips of fluid on the ground. i figured the diff gasket must of split and i had a leak, no big deal..i'll just change the gasket and replace fluid. but upon further review i noticed it was a much bigger leak coming from where the driveshaft connects the differential. Is this the pinion seal?here are a couple of pics, even though the entire bottom of the diff is wet the source of the leak is where it connects the driveshaft. Is it a seal that blew? how hard of a job is it to replace it...and is it worth doing myself? i noticed the pinion seal itself is dirt cheap. any input or advice is apppreciated.

 

if you read complete instructions on this procedure,you wont want to do it and you will want to find a rearend shop that actually knows what they are doing. many mechanics do not.
the pinion nut requires precision adjustment to assure proper pinion bearing load pressure.
the procedure i read required a very difficult measurement wint inch ounce torque wrenches while rotating the pinion with the wheels removed.
thats the "short story"!
talk to the shop to see if they have a proper procedure,,dont trust"oh yeah" bs

 

oh yeah........

well not really, I haven't done it. I did have a front pinion seal replaced under warranty but I think the price on the sheet was around $250 if i were to pay for it fyi

 

oh yeah!!,,,not ez,,,not cheap!

 

I can't say if for some reason it's a completely different procedure , since i've never done it on an h3 but i've changed pinion seals on other gm., jeep and dodge vehicles and it's not an especially difficult job. An impact works best rather than a ractchet but it will work also. As long as you tighten up the nut to specs it should be no problem. Go to autoMd under drivetrain repairs and they explain it completely. the last one I did was on my son-in-laws dodge dakota and that was 3yrs. and 40k and no problems. There's no issue with with anything else in the diff case if you're just replacing the pinion seal and retorque the nut to specs.

 

i reread the gm procedure and it does sound reasonable compared to what i read b4, mostly ford,probably older stuff,9 inch etc. good luck,,report back!

 

thanks for the help guys, i think i might take a crack at it myself. I did call a local shop this morning after drtom made it sound like brain surgery haha(jk dr.t, thanks for your honesty) and they said it would be $165 total which i agreed to since all i have to do is drop my key in the night box and pick it up tomorrow after work. But now that i read this how-to recommended by rfd 51 i think i can handle it. i also found another useful page with the torque specs. i might need help on which nuts i'm actually needing to torque though lol. keep the comments coming if you think i should attempt it, or if ther is anything else i should be aware of. fortunately i have a motorcycle so i have plenty of time to fix this up...or call some buddies for help!
How to Replace a Rear Pinion Seal | AutoMD

http://www.hummerworks.com/wp-conten...GE-TORQUES.pdf

Check this pdf out, i'm assuming this is a section of the gm service manual. The rear pinion seal replacement starts on page 67 of the pdf. maybe im not gonna attempt this myself. i'm not sure i even want the local shop doing this until i give them a copy of this procedure. i might have to see how much the gm dealer is gonna charge as well ;(
http://achim1000.bplaced.net/hummerf...IAL%20REAR.pdf

 

when i read the gm info it was for an EMPTY REAREND HOUSING, not a vehicle sitting on the floor with wheels!! thats what i forgot about the ford experience.
gm empty involves just the input pinion shaft,bearings,seal and yoke,no ring gear,spiders and axels!!!,,,and wheels. that obviously changes the torque required to turn the yoke!
so be careful what you are reading.

i DO NOT pretend to know how to do it!!! im only telling what i do know to help avoid trouble.
the ford info had you remove wheels,rotate the yoke with a torque wrench,and duplicate that after putting in new parts. NOT AN EZ THING TO DO. and i knew mechanics who just tightened it up till it "felt good"

so im gettin out of here with a simple warning to be careful and make sure the fixer does know what hes doing

 

I first remove the drive shaft, then scribe a line on the end of the shaft and the pinion nut. Measure the distance from the nut face to the pinion shaft face. Save this number. remove the nut (Impact) change seal, lube seal, put yoke on. Now replace nut you can run this up with the impact to near tight. measure the nut to pinion shaft distance, turn nut until you have the old number plus .001 to .008 The marks should be just a hair Past the old spot.

I have done it this way for years while not the correct process I have put 194,000 miles on repairs done this way without issue.

 

OH my goodness........don't take shortcuts! Never reuse the pinion nut. Get the darn specs, buy an inch/lb torque wrench and do it right......removing the brake pads etc. OK to use an impact to remove the nut but never,never use an impact to tighten. I have been doing this for about 50 years and have been observing "quick and easy" failures for a long long time. Some shops "mark the nut". I have witnessed multiple failures using this technique. If you go to a dealer ,the hours are computed on doing it right but most technicians use shortcuts which almost guarantee failure........!