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How to: Replace rear axle seal.

260K views 93 replies 59 participants last post by  Mickeroon 
#1 · (Edited by Moderator)
Newbie here!! I didn't see this listed any where, so after doing some research on the site, I figured I would docuement the process as I did it tonight. Straight forward and pretty easy. But might help someone out like me that never did one before.

I found my driver side seal was leaking, when I rotated my tires. Had gear oil all over my rotors and lugs. So checked the oil level in the Diff and it wasn't very low, so it must have just started.

Get the parts: Brake cleaner, seal, Blue RTV, Blue thread locker, locknut socket and Diff oil. The oil I picked up already had the limited slip additive in it, one less thing for me to remember.


Jack the truck up and put on stands:


Remove the tire and take out the 8 bolts holding the axle in:


Slide the axle out:


Note the paper gasket on the axle, no auto store near me had it in stock, so thats why I picked up some RTV. This needs to be scraped off the hub and the axle and cleaned.


Next you can remove the Caliper (two 19mm bolts on the back) and then the rotor will just slide off. Unless you have never had it off then you'll need to beat it off..

The inside of the hub:


Grab a screw drive and pop out the snap ring:


Next slide out the square Key:


Then unscrew the Lock nut from the splin with the Lock nut socket:

Now the hub is ready to come off, mine took a little pry-ing, but once it loosened up it came right out.
 
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#2 · (Edited by Moderator)
The spindle... usually the seal is in the hub when you take it off, mine stuck to the spindle, so I slid the bearing off and placed back in the hub. Then pry-ed the seal off the spindle.


After getting off the seal, I saw that the auto part store gave me the wrong ones, they are for a 1500 or a non hd truck. So back to the parts store. Here are the correct Napa seal:


The hub with out the new seal in it, just started it and the put a piece of plywood over it and hit with a dead blow till it was in all the way. Sorry forgot to get a picture of it.

next steps:
Slide the hub back on
Hand tighten the lock nut on the spindle, then torq to 52 ft/lbs. This will seat the hub on the spindle properly
Next back off the lock nut till its just finger tight and line up the key slot so you can slide the key back in.
Once the key is, place the snap ring back on.

Next I RTV the hub before sliding the axle back in.


Make sure to line the hole back up when sliding the axle in and then torq the 8 bolts to 152 ft/lbs. Doing it like you would lug nuts altering side to side.


Then slip the rotor on, put the caliper back on, the wheel on.

Last step top off the diff fluid till its just coming out of the hole.
 
#3 ·
Nice write up just getting ready to do this myself
 
#6 ·
rear axle seal replacement

Great info , I found it very helpfull. The one thing that I would make sure you have BEFORE you start is the right spindle socket- I spent 3hrs driving around to find one because no one had a listing for it. Finally found one at NAPA by matching a spindle nut which they did not know it fit because thier books did not list it .

Good luck Jaguar3500
 
#18 ·
Great info , I found it very helpfull. The one thing that I would make sure you have BEFORE you start is the right spindle socket- I spent 3hrs driving around to find one because no one had a listing for it. Finally found one at NAPA by matching a spindle nut which they did not know it fit because thier books did not list it .

Good luck Jaguar3500
def a pain to find, luckily my buddy is a tool guru and has 4 diff ones, i torqued mine to 55 ft lbs and backed it off til the key way fit into place.but I didnt use blue goo, the act. GM seals are 9 bucks and makes me feel better.
 
#7 ·
good write up! :drink

agreed about the spindle nut, we ended up taking a picture to the specialty tool shop to find one, turned out to be the same as a 90s half ton dodge IIRC??
 
#9 ·
Great write up dude,
 
#10 ·
Very Nice Write up man.....with good pics.
 
#11 ·
Thanks!..

Autozone and Advanced auto up here in new york both have the tool for rental. So you can rent it for free, or do like I did and not return it.. Then they just keep your deposit, which was only 20 bucks.. Probably a lil on the expensive end...

I figure that with 8 freinds with chevys some one will be needing it soon enough, so i'll have it for them. :)
 
#12 ·
Few small tips since I have to do these on a weekly basis at work.

-Once both caliper bolts are removed, take a thin prybar or a screw driver and stick it in one of the holes on the back of the caliper, slide it into one of the slots on the edge of the rotor, and pry it just a little bit to push the caliper pistons back. Makes for a much easier to re-install the caliper. (Don't forget to pump the brake pedal a few times before you drive off after)

- When installing the seal into the hub, try and find a piece of pipe or something that fits nicely over ONLY the metal part of the seal. These are two piece seals and if you damage the inner portion, you will most likely be replacing it again.

- If you are draining the rear differential while doing rear axle seals, make sure to pre lube the hub bearings somehow. Either by squirting some gear oil into the end of the hub before completely sliding the axle shaft back in, or by jacking up one side of the truck for a few minutes, then jack up the other side.this allows some oil to flow down the inside of the axle housing to your hubs. Sadly, I have seen a few bearings fail almost immediately after a customer drives off with thier truck due to not lubing the bearings.


If I can think of anymore, I will post them. Hopefully I can save someone a little bit of grief! :)
 
#13 ·
Great Info Man!

I just did mine while replacing my Brakes 2 months ago. I have done several other seal replacements but never on a HD and learned on my own. Good stuff though.
 
#15 ·
Don't need to replace them unless they are shot..

I just used about 1 and half cans of brake cleaner on them and got as much gear oil off as I could. rag spray rag spray, had a nice pile of rags when done, but cleaned up just fine. good luck..
 
#16 · (Edited)
I changed the axel seals on my 06 lbz and the new ones leaked worse than the old ones. I took the hubs back off and noticed a piece of the old seal was still on the spindle. So i removed the metal part of the old seal that looks kind of like a sleeve and is hard to see. replaced everything and i believe it fixed it. Drove it 30 miles and no leaks. Also, the complete hub assy. went on easier. I guess when i torqed the hub on the first time, the seal pushed the old part of the seal all the way to the back plate, which made it hard to remove. Anyone else have this problem?
 
#17 ·
Awesome write up!

Going to be doing this in a few hours on my 2500HD. The rotor is off, and diff is drained. I have to get the seals which are in stock, and the socket. So there is only one seal for the hub (is that called an inner)? The other side of the hub is sealed by the rtv and the axle shaft flange?

So the bearing is being lubricated by the gear oil, unlike my S10 (2WD) that I have to pack grease into them and the do an inner and outer seal?

After the 52 ft lbs of torq is put on the nut you back it off and only have to hand tighten the nut? I assume too tight on the nut will ruin the bearing?

Thanks!
 
#20 ·
i think, one of mine turned snug and the other kinda loose but ive put 12k miles on it since then and no leaks yet so it must be right.
 
#22 · (Edited)
Well I also may have another problem. I may have put the wrong seal in. The seal I put in had a lip on the metal ring that is on the outer part of the seal (which made it so that you can't drive the seal in too deep). The seal I took out did not have this lip on it. Gear oil is not coming out, but I really havent driven it yet. The only thing I'm wondering about is if the inner diameter of the seal (or the part that rides on the spindle) is too small. If it is too small I will severly shorten it's life.

I need to find the boxes and I can post up part numbers of the seal.

Edit: It looks like I used the same seal in the picture, which he said was the correct seal after getting the wrong seal from NAPA. So maybe I am okay? I just dont know why the replacement seal had a lip and the original seal did not...
 
#27 ·
Great info and pix which helped to just finishing mine. Here is one tip my buddy came up with on removing the wheel hub. Put the rotor over the lug bolts, but on backwards, put two lug nuts on opposite sides and just enough to catch six or so threads. The stud bolts are about two inches long so push the rotor to the inside and pull out sharply which acts like a slide hammer against the two lug nuts. I suppose you could put on more nuts in you want. The wheel hub popped right out without hammering or prying.
 
#28 ·
Good write up, definitively helped out
 
#29 ·
Nice work.
 
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