Gears & Axles - pinion seal leaking question about crush sleeve




GormanRacingZ28
12-18-2011, 08:49 PM
so my pinion seal is leaking pretty bad and i need to keep the car alive until i get my 12 bolt i work as mechanic and have pretty decent knowledge of how to perform this procedure but would like pros to chime in

so this is how i was told to do this by a world class certified gm technician i work with

1.drain fluid from diff
2.clean mating surfaces
3.mark for postion, and remove driveshaft
4. check turning torque with inch pound torque wrench record this measurement
5.remove pinion nut with impact gun

6. remove yoke and pry out old seal clean any dirt and old grime off
7.remove crush sleeve install new one install seal and yoke

NOW this is were i find it to be sketchy
STEP 8
torque NEW pinion nut to 300 ft lbs check turning torque for this will determine bearing preload if turning torque to low go in 25 ftlbs increments until desired turning torque is reached

what do yall think


FirstYrLS1Z
12-18-2011, 10:01 PM
mostly true
#6-when you check existing rotational torque,you'll be measuring pinion,carrier,axles,rims/tires rotational force. Will be much higher than measuring pinion only/alone. It's best done with everything,except pinion,out of rearend housing,but you won't be doing it that way.
#8-torque pinion nut to attain an identical rotational torque as measured before dis-assembly. You will not necessarily need 300ft.lbs,but you might. Procedure would be torque pinion nut,measure rotational torque,repeat in small increments to avoid overtorqueing and attaining too high of a rotational force. Since you didn't mention anything about changing bearings,you should/could go a few in.lbs. higher as used bearings will have loosened up since initial factory assembly.
Yoke surface that contacts the seal needs to be free of defects.
Apply some kind of sealer to yoke/pinion splines as lube can work its' way thru the splines and appear as a leak.

GormanRacingZ28
12-18-2011, 10:14 PM
awesome thanks for input man is the pinion bearing pressed on in the 10 bolts just wondering yea and the service manual says to go tighter with new bearings for that they will lossen up and old bearings have already worn and seted in there presepective races


Macs98Z
12-18-2011, 10:30 PM
Are you needing to replace the crush sleeve or you just want to while you're there? You don't necessarily have to... I just replaced my leaky pinion seal a couple months ago and left mine in. I just scribed a mark across the pinion nut and shaft end to mark it's placement, counted the number of turns to take it out, and replaced the pinion seal. When re-installing the pinion nut, I counted down the number of turns until I got where I was supposed to be, then went about a 1/8" or 1/16" (I can't remember which) past where I had put the the mark across the nut and pinion shaft end. No problems so far, and it has been done by others with success. Much easier than installing a new crush sleeve and having to deal with the rotational torque added by the rear diff, axles, and wheels. Just a suggestion...

Scott

FirstYrLS1Z
12-19-2011, 06:22 AM
^^^ it simplifies the procedure to just replace the seal and leave the crush sleeve as is.

jimmyblue
12-19-2011, 11:14 AM
There's two reasons for the pinion seal to weep. One is wear.

The other is pinion play, which will kick the seal off seat at
speed as the driveline bumps the yoke. This is the crush
sleeve's job, to keep that tight, but after 10 years of a
daily beating, it's probably been crushed some more. A
hard spacer can help this (consider it for your 12-bolt too).

Fixing the seal when it's a play problem, will likely leave you
with the same or only somewhat reduced weepage.

Now your best solution might be more like this:

1) get piece of cardboard
2) position appropriately under pumpkin when parked
3) wipe weekly, fill monthly
4) wait for 12-bolt to arrive

SSCamaro99_3
12-19-2011, 01:17 PM
I had this procedure done one time. About 3 months later my pinion bearing was trashed. If everything is not put back together perfect, you will likely have issues down the road. i would consider it an extremely temporary repair.

Macs98Z
12-19-2011, 01:31 PM
I had this procedure done one time. About 3 months later my pinion bearing was trashed. If everything is not put back together perfect, you will likely have issues down the road. i would consider it an extremely temporary repair.

Did you replace the crush sleeve as well or just the pinion seal?

JRENIGAR
12-19-2011, 06:07 PM
just the pinion seal about 20,000 miles ago and been fine holding 450rwhp with 315 sumitomo street tires.

SSCamaro99_3
12-20-2011, 11:08 AM
Did you replace the crush sleeve as well or just the pinion seal?

Just the pinion seal.

Macs98Z
12-20-2011, 11:19 AM
Just the pinion seal.

Interesting... I'm assuming by the sound of your first post you had someone else do the work? If not, what steps did you go through to do the job? You're starting to make me nervous that my rear is going to have the same problems now, haha.

JRENIGAR
12-20-2011, 02:48 PM
Mine went as fololows: remove drivshaft, remove pinion nut and pinion yoke, use seal puller or medium common screwdriver to remove seal, clean seal mating surface with degreaser to remove all oil, slide new seal on pinion shaft and seat fully, replace pinion yoke, tighten pinion nut till all side to side and front to back slack has gone from pinion shaft and then add just a little more, (maybe 1/4 turn if that much). Drink favorite beverage and pocket $50-$100... I like to use a big pair of Channel Lock pliers to keep the yoke from turning while removing and installing pinion nut...

GormanRacingZ28
12-21-2011, 09:42 PM
yea they rear end decided to go belly up and shit out i am just so pissed i just checked the fluid leel to was at the bottom of inspection plug rear end trashed i will find out what failed and post on here

Macs98Z
12-21-2011, 10:21 PM
yea they rear end decided to go belly up and shit out i am just so pissed i just checked the fluid leel to was at the bottom of inspection plug rear end trashed i will find out what failed and post on here

Really sorry to hear that man. I have been dreading this happening to me as well--hoping to avoid it. Let us know what happened. Are you A4 or M6?

GormanRacingZ28
12-22-2011, 08:25 PM
found a carrier bearing race pitted and blued it got really hot and it looks like godzilla bit into and shit the chunks out in the third member fluid was new and correct level before dissasembly also i am the 2nd owner first owner was my neighbor who has more money than brains and never took care of the car so i bought it being a one owner M6 ws6 with 29k miles for 6k not bad but i knew something had to give and it was the ol 10 bolt in the ass