rear differential lube and reseal
 

so i have love stains all over my driveway from a rear differential leak. i have a visible drip accumulated at the bottom of the diff at all times. how do i go about crackin this thing open to reseal it.

Drain the fluid, drop the drive shaft, pull the axles, pull the diff. Clean the surfaces with brake cleaner, wipe them down, let dry and apply some RTV. Let the RTV sit for about 10 minutes, install the diff, tighten the nuts until the RTV pushes out a little at the edges, let sit for 15 minutes, tighten the nuts, reinstall the axles, reinstall the drive shaft, torque the nuts to factory specs, put fluid back in it and drive it like you stole it.

Or you can check to be sure the nuts are all tight. I had this issue with mine when I first got it and half of the nuts were loose.

Read the instructions on the RTV. And let it skin first before applying, you'll get the best results.
The paper gasket and rusted studs can make removing the diff a bit of a pain. Pickle fork and a long flat screwdrive to wedge it out works good.

Where exactly is it leaing from? Make sure it is not a fill or drain plug leak or a pinion seal leak before you get too involved. IMHO pinion seals are easier to replace than cracking the whole diff open.

I'm not sure. I feel hear something vibrating when I take off and slow down to a stop. The bottom of the diff housing looks wet around where the drip is. I hope I didn't screw up my gears as I have noticed the noise for about 2 weeks driving everyday.

Might want to check your u-joints in the rear driveshaft as well, mine went out and the pinion seal started to leak a little and accumulated the same. Stopped leaking after the new u-joints and hasnt for the last year or so. Oh and when you change the diff seal, have an extra hand ready as they are very heavy

had my shop teacher friend print out the all data info for this job. turns out a few of the nuts were loose on the bottom with the loss of only a few mm of oil. im just trying to figure out where this vibrating noise in the rear comes from when i take off and come to a stop.

Like the fact my 86' has a sealed. Makes draining and filling simple and quick. Just waiting for my third member to leak so I can do this as well.. haha Pinion seals would get replaced as well since I'm already in there.

Probably your pinion nut is loose. Hopefully it didn't screw up the pinion bearing. If the oil is runing down the diff from where the driveshaft bolts to the diff, then it's the pinion seal leaking. You'd need to drop the rear shaft, unstake the pinion bolt, unscrew it, pull off the flange, get the old seal out. I think on your model there's a crush sleeve in there so you'll need a new crush sleeve as well as a new seal. If you don't have one, download an FSM for your truck from TTORA, it describes the process. That's probably the cause of your leak, but if the nut is loose, and has been for long enough, you may have damaged the pinion bearing.

If it's the actual housing leaking...then listen to the above advice...drain the fluid, drop driveshaft, pull axle shafts, then pull the diff.

my diff is leaking a bit from the pinion too? it started leaking a couple months ago i think? anyways the oil leak hasn't reached the bottom of the diff yet so its nothing bad but i think i should fix it haha. any tips? should i just drain the oil, pull the drive shaft, unbolt the flange, and replace the seal like you where saying? makes sence but i might have toasted the bearing? because my leaf spring snapped and my axle wasn't center so it might of messed something up? anyways sorry about the highjack but this could be some valuable info lol

There's a little more to doing the Pinion seal than described. You can screw up your gear pattern if you don't get the pinion nut back exactly how it was on there before. That crush sleeve sets the pinion depth and your gear pattern. Also most times when a pinion seal goes it's because the diff breather is plugged. When you drive and and the fluid heats up pressure builds up inside the diff. The diff breather is a little one way valve located on the top of your axle and slightly offset to one side. They are cheap and easy to replace. If the diff can't breath oil starts finding ways to get out while under pressure.

ok so good chance my breather is clogged? im still going to need to fix the seal though... i guess i will look for a thread on how to do it perfect lol thanks