10 bolt rear end leak

**JayTA98** · 05-22-2013, 06:00 AM

I had this rear end leak going on for quite some time and it makes a mess underneath the car. I maybe see a drop or two on the floor maybe once a week. I was thinking the pinion seal may be bad. I decided to clean everything with degreaser and brake cleaner. I cleaned all the surfaces with rags underneath the car and the exhaust. I cleaned the whole rear end and it looked completely dry. I checked the rear end fluid by pulling the plug and about a 1/4 cup of fluid came out like it was over filled. I don't know how could be overfilled because last time I replaced the fluid I filled it up to the bottom of the fill hole, anyways so I put the plug back and run the car for 2 days. This morning i decided to look underneath to check for a leak. There is no leak coming from the pinion area or the splines as far I can see. There is no over spray under the car. I did noticed a couple of areas in the bottom and side bottom of the rear end(solid metal areas no bolts, gaskets, etc) that are wet like the fluid is leaking. I did noticed that it looks like I also have a bad bearing seal on the right passenger side.

Is it possible for the rear end leak from another area besides the pinion, bearing and cover gaskets? Is it possible the case is cracked? I'm going to clean everything again including the wheel and recheck. Are there any recommendations on the best bearing seals? I have been using timken and it seems to last about 6-8 months before i see it leaks. Thanks.

**pajeff02** · 05-22-2013, 05:53 PM

Most common leak on a stock 10 bolt is the pinion seal. Almost all of them do it to some extent.

**JayTA98** · 05-22-2013, 05:56 PM

hmm I will check tomorrow again and see.

**pajeff02** · 05-22-2013, 06:04 PM

Since you just cleaned everything, it may take a while to show up again. Other possibility is where the axle tubes attach to the differential housing. If it is leaking there, just clean up the joint and run a bead of Permatex Black Silicone sealant around the entire circumference.

**JayTA98** · 05-23-2013, 07:57 AM

Originally Posted by pajeff02

Since you just cleaned everything, it may take a while to show up again. Other possibility is where the axle tubes attach to the differential housing. If it is leaking there, just clean up the joint and run a bead of Permatex Black Silicone sealant around the entire circumference.

Ok I will check later and update. I'm concern that if I replace the pinion seal and it leaks worse then I will have to service the rear end. I read you can't keep changing the seal because of the crush sleeve getting ruined after the 1st change. My 10 bolt is still running strong and don't really want to get a 12 bolt specially if I might get rid of the vehicle after October. If I decide to keep it then I might do the investment but I only do DD with my car anyway. thx Jeff.

**pajeff02** · 05-23-2013, 09:24 AM

There is a "cheater method" of swapping the seal and re-using the existing crush sleeve. Remove the driveshaft and using a beam style inch-pound torque wrench rotate the nut clockwise and obtain a reading on the torque wrench of how much pressure it takes to turn the differential. Then, mark the nut, yoke and differential flange using a punch so that when you reinstall the nut you can tighten it to exactly where it was. Remove the nut and yoke and then replace the seal. Spin the nut back on to line up the punch marks and take a reading with the torque wrench. You'll probably have to then tighten the nut just a smidge more until you achieve the same readings on the torque wrench -- this should essentially match your bearing pre-load prior to removal. Be sure to lube the lip of your new seal upon installation.