ok my car had the oringal pinion seal and it was starting to seap a couple drops everyday. so i put in a new seal and it leaked worse. found out the nut wasnt tight. put in another seal and made sure the nut was tight yesterday. still leaked. this morning found out the nut was backing off so i put on a new nut. i also put on a seal saver sleave just in case the pinion shaft was worn. just got home and it still leaks. what else could it be??

 

is your vent tube pluged? IF you have too much gear oil in it and vent tube is pluged that might be a problem

 

would the vent tube cause the pinon to leak? why would my nut keep backing off also?

by the way something has started clunking under the car which may not even have any thing to do with the rearend. when i hammer the gas and let off and when going over rough bumps it feels like something is beathing the floor, but im not sure where.

i really cant figure out why it keeps leaking though!

 

Pull the cover and do a brief inspection of the differential and magnet.. look for anything out of the ordinary and shrapnal attatched to the magnet.

Honestly it sounds like your pinion nut isn't torqed on completey. It's very tricky to get the pinion nut to stay on if your not using the right tools. A good method is to apply some "RED" thread locker and torque the nut on using an impact wrench. There has to be a certain amount of "preload" on the nut to "crush" the Pinion sleeve properly. If the Pinion nut is not on tight enough and is not "crushing" the sleeve then there is "slack" still in the assembly. This can create noise and "clunky" feelings when going over bumps. It will only get worse unless you get the "preload" right. Getting the Pinion nut to set right is difficult and there's allot of ways to do it... but when I did mine I had the differential out and held the Pinion and Jammed the nut on with the impact gun till I could no longer move the pinion back and forth and the slack was gone...the pinion was tight enough to make one half a turn...loosly and then stiffen up... that's when you have the "preload" right honestly no one knows how much pressure it's going to take to crush the pinion sleave to remove the slack and set the preload right... setting up gears its a hit or miss thing. I think it's said to be 76inch lbs in the book to get the load right... but anyone who's done a gear change before knows that junk.

Also how are you taking the old pinion seal off? Sometimes when people pry the seal off they create gouges in the pinion housing and when the gear oil heats up it can seap through the gouges and cause a leak.. check for that, the metal that the rear end is made out of is pretty soft and easy to nick...gotta be careful... also don't be affraid to use a bit of silicone around the pinion seal... It took care of my leak...

good luck!

Once upon a time when I was young and nieve I took my car to a shop for a gear change... the morons there didn't know what the hell they were doing and 2 weeks later rear end litterally fell apart.

 

i give up. pinion bearing?? i need help with this before i burn it up

 

What is the proper method in replacing the pinion seal correctly? I've heard most people just "mark" where the pinion nut was before you take it off and you just torque it down to where it was..

I tried replacing mine a few months ago but I believe Moser uses some good loc-tite cause I couldnt get that nut off..Now I have an impact so I should be able to do it..

1)Mark the nut for reference and remove
2)Pull old seal out
3)Put new seal in..is there a trick to do this?
4)Torque nut back to spec..

This sound correct?

Cody

 

i cant figure out the problem im having. i work at a dealership with some ex gm techs and no one knows the problem but they think pinion bearing? maybe some silcone around the outside of the seal and tighten that nut down a whole lot? by the way i didnt notice there being a vent tube. would that make it sling out oil? how would i actually know if is the bearing?

 

A busted driveshaft earlier in the rear ends life might be responsible for this. My pinion seal never leaked until I broke my driveshaft going 100 mph or so. The driveshaft bounced around everywhere and rattled everything pretty good, so I imagine my rear is just nicked somewhere around where that seal seats. I've replaced the seal once and it still leaks so I just accept the fact that I will have a leaky rear end. Maybe something similar happened to you.

 

the ideal method for replacement would be to record the torque required to turn the pinion. By simply re-torquing the nut to the same place that it was, doesn't often times put things back exactly. If the nut is too loose it will still leak, if too tight, the crush sleeve gets deformed further. This is why you want to measure rotational torque and put things back exactly how it was taken apart.

Why not go with the solid spacer?

 

i fixed it a few months ago. i siliconed the **** out of a new seal and put on another new nut. no leaks at all. i cant believe something that simple fixed it.

 

If you broke the driveshaft, there is a good chance on you having a bent pinion, maybe one reason why there is a leak.