rear end seal replacement

[dan42]

My differential decided it was time to start leaking oil all over the garage, and I don't blame it, considering they are probably the original seals. The pumpkin cover is pretty straightforward, it looks like I can do that without removing the tracking bar, but can anyone tell me the easiest way to replace the front seal? I've never done that one before. Here's a couple of pictures -

[dan42]

ttt

[mindhive]

Remove the drive shaft from the pinion and lay it aside. Remove the pinion nut with an impact gun. The pinion should slide off without too much difficulty. It is a splined slip fit but you might have to tap the pinion a couple times lightly with a hammer. Pull the old seal put in a new one and reassemble. Not sure on the tourque spec for the nut though.

Tim

[ERASER5]

I just replaced one on one of my vehicles. I just read my Hanes manual and did it.

Lift the truck and remove wheels.

Remove the U-joint straps on the yoke and carefully pull the U-joint/drive shaft out of the yoke. Be careful not knock off the bearing caps. Use tape around the joint to keep the caps in place while you are working.

Now comes the touchy part. You need an inch-pound torque wrench and adapters to fit the pinion nut. Now use the torque wrench to turn the nut. Record the torque reading. Mine was about 55 in-lbs.

Now you will need a large pipe wrench and a big breaker bar. The pipe wrench goes on the yoke and of course the breaker bar on the pinion nut. Put some muscle to it. The torque likely over 200 ft-lbs.

Once the nut and washer is off, you must pull the yoke off. I just used a two jaw puller. Once years ago, I just used a long punch and hammer.

The seal must be torn out much like the front seal of the timing cover.

The new seal drives in. Use a large socket for this and drive it in SQUARELY! There are no second chances.

Oil the lip of the seal. Re-install the yoke. Tap it in with a hammer.

Now squirt RTV around the shaft at the back of the yoke. Now put the washer over the RTV.

Install the nut and tighten. When you get the nut tight, check the rotating torque like you did earlier. You want your original torque reading plus about 10 in-lbs for the new seal.

Keep going back and forth until the rotating torque is correct.

Re-install the U-joint and drive shaft.

Top off the gear oil and you are done. Unless you want to pull the cover and fix the leak there.

Put the tires on and lower the truck. And drive it.

[dan42]

Thank you guys. Sounds like a little bit of a PITA, but I think I might try it just the same. Definitely doesn't sound like brain surgery.

[Tx Firefighter]

Before you change anything, take the hose off of the breather and make sure it's free and open. Lots of times when they get stopped up, the pressure in the differential housing has to go somewhere, so new leaks develop. I've seen it more than a few times. We have things called dirt daubers here in Texas that build mud nests in the hoses.

[mclairmo]

Do you have a pic of a dirt dauber?

[Tx Firefighter]

yes...

[WorkinLonghorn]

just a note; I know that Haynes says to lift the truck etc. but I just do mine on the ground with the parking brake on and the wheels choked and you don't need a yoke holder. That Drive Pinion Nut should be torqued to 220 ft.lbs.

[Wrenchbender Ret]

The easiest way to go back to the original pinion nut setting is to mark the nut & shaft with a center punch before you remove the nut. Then tighten it back to the original possition. A little locktight is a good idea.

[mclairmo]

Holy crap, that dirt dauber is horrible looking. Do they bite people?

[ERASER5]

Bite? Yes! Sting? No, but dang that bite hurts!