I have one seal that is leaking on my truck. Nothing sounds amiss with the bearings. I have two questions: 1) should I replace the bearings while replacing the seal if they don’t seem to need it? Bearing replacement seems a lot of work if it isn’t needed. 2) Should I replace the seal and or bearings in the other side while I’m at it or wait until it starts leaking?

Truck is a 2005 GMC Duramax with 210,00 miles.

Thanks.

CT

I'd replace both at the same time and in pairs.
Although if the bearings are fine you could optionally just do the seal(s).

Most of the time you can't remove the bearing to replace the seal without potentially damage, sometimes not obvious until later.

Bearings have an effective life of about 150k miles. While they might not fail, they are worn.

I just bought a 2007 jeep grand cherokee with 146k miles on it. I changed out the hubs as a matter of principal.

There is a significant difference in how the jeep rolls.

I had bought a 2002 Duramax and one of the rear seals started leaking around 20,000 miles. Under warranty so not a big deal at the time.
With the mileage you have on your truck I would do the seals and bearings now. You have to do one seal anyway, and depending on how long you plan to drive the truck it makes sense to do some PM on the other side.

Bearings really aren't bad to swap, just a greasy mess. Can rent a bearing race and seal driver set for the day at most auto parts places.

I would do them both, and while you're there, do a rear end drain and fill.

You don't really need to replace the bearings, unless of course they are bad. Do you have a full floating rear axle? Most 2500s and all 3500s do.



The bearings run in a constant oil bath and rarely go bad unless the differential oil is very low or contaminated. But you do want to pre-lube them before putting the hub back together, or they can starve for oil until enough travels back up the axle shaft.

I would only replace the one sides seal, inspect the bearing and if it's good, call it done.


If it ain't broke, don't fix it.

If the axle seal - on either type - is leaking enough for you to see it on the outside, the little parking brake shoes inside the "hat" part of the rotor are probably saturated.

Egregore- this is the info I was looking for. My truck does have the floating axle. I Figured that the bearings would be ok on this truck/application seeing as I didn’t hear anything screeching or any other signs of bad bearings. When I changed the brakes and rotors I thought I noticed a small amount of oil in the space where the axle flange and the spindle meet. I took off the wheel/tire today and didn’t really notice anything more than 3000 miles ago when I did the brakes. No dripping or mess anywhere else and my fluid level was full in the rear diff. I may hold off on changing it.

Thanks for the info again.

CT

I'd do both bearings and seals with that kind of mileage and change the differential fluid while you're at it. If the bearing is worn and sloppy that can eat the seal. I'd do the parking brake shoes at the same time.

quote:

Originally posted by egregore:


The bearings run in a constant oil bath and rarely go bad unless the differential oil is very low or contaminated. But you do want to pre-lube them before putting the hub back together, or they can starve for oil until enough travels back up the axle shaft.

Definitely follow this advice.

I will add one thing further that I do. After pre-lubing, assembly and filling the differential, I raise the opposite side of the differential so that fluid will flow to the side just repaired. If I replace both sides, I will do this to both sides. After raising both sides, I then check the fluid level again and fill as necessary.

You’re gonna want to purchase the appropriate socket to remove the axle. They have them specifically for that purpose at your favorite autoparts store for about $20. You’ll see folks on youtube using a chisel; I dont recommend that.

Save yourself the headache and replace the bearings along with the seals.

Read the factory manual for your exact axle. There are minor differences in regards to proper hub nut torque sequence.
Every YouTube 'expert' has their own opinion (which is normally wrong).

The above advice is after completing the task on a Chevy 2500-3500 14-bolt corporate.

quote:

When I changed the brakes and rotors I thought I noticed a small amount of oil in the space where the axle flange and the spindle meet.

That little bit? I wouldn't mess with it. If it ain't broke, keep fixing it until it is. This seal has a trap that will snare you unless you know what to look for, and a special socket is needed to properly TORQUE the nut. A hammer and punch or chisel may work half-assed on older full-floating axle nuts, but not this one.

Speaking of this socket, this is the rear spindle nut for this truck.


(You might need it in case somebody used a hammer and chisel on it.)

The teeth on the socket engage the half-moon-shaped cutouts on the outside of the nut. Every damned socket I looked at, even from Snap-On and Mac, supposedly designed for this nut, had square teeth. I finally ground a radius on the back side of the teeth to make it work.

^^^ Yep, teeth are all square. I filed two corners of every tit, at a 45 degree angle until it fit good.
The spacing was a little off on a couple of them, so a couple had to be filed on the sides as well.