It looks like I'm leaking gear oil where the drive shaft goes into the differential. Is this just a seal I need to replace? How involved/ difficult is it?

 

I would replace the seal, and also check the yoke shaft for excessive wear at the seal groove.

 

I would go ahead and replace the bearing, seal and sleeve to be honest cause they are all pretty cheap (protect that expensive ring an pinion!), while your at it, check your flanges for warping and your outer axle bearings for wear.

As far as replacement goes...

Remove tires, exterior drums and whatever else is needed to slide out axle (I think that's it actually?)
Remove differential cover, loosen carrier bearings and outer axle shims for LSD, slide axles together and remove inner shims inside of the LSD, unbolt LSD pin (hard to miss, its either an allen nut which will be inset or a single small bolt that is on the outside of the LSD) and slide/tap out LSD pin. Remove the "S" plate (dunno whats its called, buts its obvious what I'm refering to). Slide axles out, and remove LSD from diff.

Remove driveshaft (loosen bolts at flange, and pry/hammer driveshaft flange off pinion flange), unbolt pinion nut from driveshaft flange and hammer out pinion gear to remove.

Remove bearing, and seal from diff housing, then remove bearing sleeve (might need a slide hammer, you can "rent" these from auto parts stores).

Clean diff housing.

Install new sleeve and make sure its seated against pinion exit area (near the driveshaft flange's area), installation of the other parts is the reverse of removal (note that you might need to "pack" the bearing though).

This is general idea of what you can expect, sounds harder than it is (so long as you have a slide hammer [I have two sets, lol]).

LSD = Limited Slip Differential.
diff. = differential housing

 

Or you could just remove the drive shaft, pinion nut, then the yoke. Pry old seal out, install new and re-assemble. No need to take everything apart for a pinion seal.

 

Hmm, good point, but I would disassemble it all (because its not difficult to begin with) to check the condition of the LSD, seals and bearings as well, just saying it takes about a total of 3 hours to take it all apart and put it all back together.

Thats just me though, but yea no need to take it apart if you don't want too :P

 

I don't believe I have a LSD according to my axle code; 19 something if I remember I'd have to look again.

 

Anytime you remove the pinion nut you need to take in consideration the preload on the pinion bearing. The quick and dirty method is to mark the pinion nut, remove it, install a new seal then re-install the pinion nut and tighten it to match up to the mark.

The textbook method (para-phrased) is to remove the nut, seal, crush sleeve, axles then install a new seal and a new crush sleeve. Reinstall the pinion nut then tighten until you get the proper preload, which is measured in inch-lbs. Then put the axles back in.

I have used both methods with success.

 

What do I need to get when I go to the auto store; what's this seal called? Also, just to make sure we are talking about the same thing because I saw mention of the axle which confused me. Its leaking at the universal joint, where the drive shaft enters the differential. Are you just using driveshaft and axle interchangeably? I figured the axle was what the wheels are actually mounted to, just want to make sure. How long should I figure on this taking me? It seems to be a decent leak so I figure I better take care of it instead of just living with it for now.

Edit:
I found this YouTube link: Even though its for a different truck is this what I can expect or is the process different? If this is all there is to it it doesn't seem all that hard and seems like it wouldn't take too long. Thanks!

 

You need a pinion seal:


The last time I did a "cheap and dirty" pinion seal replacement it took less than an hour. Removed the driveshaft, marked the pinion nut, removed it, removed the flange/yoke, pulled the seal, tapped in a new seal, re-installed the yoke/flange, re-installed the pinion nut and tightened it back down to the mark, re-installed the driveshaft, done.

That was over 12 years ago...the truck is still going strong.

 

I use the same method rla2005 mentioned on almost a daily basis. In fact, I just did a pinion seal on a Jeep Thursday.

It is pretty straight forward to do. As he said, mark the nut to flange to splines. Pull everything apart and pop out the old seal. Check the flange shaft to make sure the seal did not wear into it cause that can cause another leak... Polish it up with some emery cloth. Tap in the new pinion seal and run the nut back on. You can do it by feel with experience but its not a bad idea to have a beam style or dial torque wrench on hand to check your rolling torque. Usually its around 15 inch pound but you can check to be sure. And its done.

 

Ok cool. I just searched for pinion seal on advance auto website and a couple things came up; oil seal and redi-sleeve. Several of each came up, I'm guessing its dependent on the specific differential? Any way to figure this out? I know there's suppose to be a metal tag on there but I can see where it was suppose to be and it got ripped off. Also, what is this redi-sleeve? On a side note, is the front seal the same to replace or no? I'll have to do that one next.

 

A Redi-sleeve is used to cover over the area on an axle or other machined surface that has grooves wore into it where the existing seal lines up. It's a band-aid fix at best. If your existing pinion flange does not have any grooves/scaring then you do not need to worry about purchasing one.

You should be able to purchase a simple pinion seal like this National brand 3604 for the rear 8.8" axle on your truck:


The front Dana/Ford 44 uses a similar setup for the pinion as the rear axle. You should be able to do the same procedure.

 

Sorry to bring back an old thread but I finally got around to doing this. I was getting ready to put everything back together but wanted to run something by you guys before I did. It looks like there is a small gap between the bearings and I guess it would be the sleeve. I was wondering what if any gap is acceptable? Is it suppose to be a tight fit in there or what? I tried to take a couple of pictures:




If the bearings need replacing can I do it without taking anything else apart?