66 1/2 ton gmc axle seal replacement

[66gmckid123]

As a novice to the car world I need some help. I have leaking axle seals, confirmed after I redid the brakes. I have the dana rear end, and would like some tips on how to remove the axles to replace the seals. It's leaking right at the backing plate and I couldn't find a diagram or locate a manual for this year truck to help me out. My uncle told me it's not hard, coming from a mechanic, but he couldn't remember if the axles are pull out or not. Any tips would be much appreciated.

[krayzog]

I pulled mine out to replace the axel seals last weekend. It was really easy, just pull the diff. cover, remove the spider gears, C clip and slip the axels out. I found a good video on youtube that helped my confidence level as well.

[Captainfab]

The Dana 44 uses C-clip axles. To remove them, pull the rear cover and remove the crosspin retaining bolt. It should be on the right side. Hopefully it isn't broken, if it is report back. Once the retaining bolt is removed, slide the crosspin out (it is aprox 1" in diameter). You may have to rotate the carrier some to get it completely out. Once the pin is out, 2 spider gears may fall out. Just keep track of them and any shims that may be under them. Now slide both axles towards the center, and the C-clips should fall out. Then you can pull the axles out. Once the seals are replaced, just reverse the procedure, seal the cover with a new gasket, and fill with 80W90 gear oil.

[slorio]

Boys:
I need to correct you here The Dana 44 doesn't use C clips. It is easy to pull the axles out. Just unbolt the four bolts on the retainer on each side under the brake drums and slide them out. Once you have them out, you will see the seals inside the differential housing. You need to hook them and pull them out, then tap some new ones in. Also, check the sealing surface on the axles. Mine were pretty worn and tore up the seals until I did the job the second time and installed a Speedi Sleeve. You can buy these from the bearing houses. They are a very thin bushing that covers any damage on the sealing surface of the axle. Also, check your axle bearings to be sure they are not worn and still have some grease left in them. The axle bearings are sealed bearings and don't receive any lubrication from the differential. It is a good idea to replace them as well if you find them either dry or rough when you turn them.

I hope this helps.
Regards,
Steve
New Orleans

PS Check out 6066gmcguy.org for a discussion group specific to GMC's. They do have some differences from the Chevies, like using the Dana 44 axle.

[66gmckid123]

Thanks for the reply this is how I thought the axles came out. I'll tackle this on the weekend, as the parts houses have to order the seals and possibly bearings.

[nbrfd007]

Originally Posted by slorio

Boys:
I need to correct you here The Dana 44 doesn't use C clips. It is easy to pull the axles out. Just unbolt the four bolts on the retainer on each side under the brake drums and slide them out. Once you have them out, you will see the seals inside the differential housing. You need to hook them and pull them out, then tap some new ones in. Also, check the sealing surface on the axles. Mine were pretty worn and tore up the seals until I did the job the second time and installed a Speedi Sleeve. You can buy these from the bearing houses. They are a very thin bushing that covers any damage on the sealing surface of the axle. Also, check your axle bearings to be sure they are not worn and still have some grease left in them. The axle bearings are sealed bearings and don't receive any lubrication from the differential. It is a good idea to replace them as well if you find them either dry or rough when you turn them.

I hope this helps.
Regards,
Steve
New Orleans

PS Check out 6066gmcguy.org for a discussion group specific to GMC's. They do have some differences from the Chevies, like using the Dana 44 axle.

I agree! Replace them bearings now, save you in the future.
Tim

[Captainfab]

I stand corrected. I could have swore the Dana 44's had C-clip axles.

Originally Posted by slorio

Boys:
I need to correct you here The Dana 44 doesn't use C clips. It is easy to pull the axles out. Just unbolt the four bolts on the retainer on each side under the brake drums and slide them out. Once you have them out, you will see the seals inside the differential housing. You need to hook them and pull them out, then tap some new ones in. Also, check the sealing surface on the axles. Mine were pretty worn and tore up the seals until I did the job the second time and installed a Speedi Sleeve. You can buy these from the bearing houses. They are a very thin bushing that covers any damage on the sealing surface of the axle. Also, check your axle bearings to be sure they are not worn and still have some grease left in them. The axle bearings are sealed bearings and don't receive any lubrication from the differential. It is a good idea to replace them as well if you find them either dry or rough when you turn them.

I hope this helps.
Regards,
Steve
New Orleans

PS Check out 6066gmcguy.org for a discussion group specific to GMC's. They do have some differences from the Chevies, like using the Dana 44 axle.

[blackedoutharley]

If you have it apart to do the seals just bite the bullet and do the bearings at the same time.

[66gmckid123]

I'm going to do the bearings as well, when i called napa they are calling for 2 bearings on each side of the differential for the axles. Is this true, as I've never cracked open this diff before? My napa part guys are pretty terrible when it comes to old stuff, if anyone had the correct part number for the seals and bearings it would be much appreciated. Thanks.

[slorio]

The differential does have two bearings on each side an inner that supports the differential chunk and an outer that supports the axle. The inner is bathed in geal oil. Unless you have some noise in the rear end, I wouldn't worry about the inner.

The outer axle bearing is part number SKF 88128R from my notes when I changed mine and the seal is SKF 15142. I would change those, check the fluid in the rear, then try it out before you went any further with the inner bearings.
regards,
Steve
New Orleans

[bama63]

here ya go...all of the following are timken numbers.

450067 wheel seal with leaf spring rear

8835S wheel seal with coil spring rear

6408 wheel bearing

TRP1559TV repair bearing, replaces original bearing and seal

[66gmckid123]

Another novice question, to remove the bearings i'm assuming that I will need a slide hammer and the correct puller. I'm going to run to harbor freight today and after looking online I'm not sure what the correct puller would be? Some help would be much appreciated.l

[slorio]

The outer bearing comes out on the axle. Normally these need to be pressed off with a hydraulic press then pressed back on. Alternatively, they can be cut off with a torch, but you have to be careful not to cut through to the axle. You would still need to have the new ones pressed back on.

Most NAPA dealers or truck parts dealers can do that for you. IThe cost to have them press them is normally pretty reasonable. I think I paid about $15 per side.

Regards,
Steve
New Orleans