Replacing rear axle oil seal on 03-07classic 2500HD

Discussion in 'How-to Guides' started by DCRoyale, Feb 19, 2011.

  1. DCRoyale

    DCRoyale New Member

    This may be old hat for seasoned mechanics, but I searched the forums as well as the internet trying to find out how to replace the oil seals on my rear axles.... All the posts I could find were for the 1500's or LD's with open differentials and talked about removing the pinion, c-clips, etc to get the axles out.

    My 2500HD has the full float 4.10 14 bolt differential with G80.

    The oil seal for these axles are located on the back side of the wheel hub. The axle does have to be removed, but for these units, you do NOT have to open up the differential.:lol:

    Here is how I did it... may be some shortcuts, feel free to comment if you know of a better way.

    Total process took me about 4 hours but that's because much of it was trial and error without a good guide. I think I could do it again in around an hour.

    1. Jack side of vehicle seal is to be replaced on and use jack stand to support housing.

    2. Remove tire/wheel from vehicle (this is an 8 bolt pattern on these trucks)

    3. Remove brake caliper assembly and bracket. (I removed the two bolts for the bracket and left the entire assembly together. Sit it on the leaf spring and there is no need to remove the brake line)

    4. Loosen 8 bolts on end of axle from hub. (This is what holds in the axle on these models where on the light duties they have the C clip in the differential)

    5. Remove disk/drum from the studs and carefully place to side. (You could have removed this before loosening the axle bolts, but I found it was easier to use the emergency brake to hold the assembly while breaking the bolts loose... remember to disengage the emergency brake or it will be impossible to remove the disk/drum.)

    6. Place pan, towel, etc below axle end to catch oil in the hub assembly.

    7. Finish removing the 8 axle bolts from the wheel hub.

    8. Slide axle out of housing and carefully place to side.

    9. Remove spring clip from threaded area. (I used a pocket slotted screwdriver and it was able to be easily removed.)

    10. Remove key stock between threaded area and locking nut. (This is what the spring clip holds in)

    11. Remove locking nut. A gentle tap may be required to 'break it loose' but once it's able to be turned, it comes off effortlessly.

    12. Gently pry hub off spindle.

    13. Remove oil seal from back of wheel hub assembly.

    14. Oil or grease new oil seal before attempting to install to avoid tearing or distorting new seal.

    15. Gently tap new oil seal into place using a seal tool or soft faced hammer. Take care to install evenly and do not damage the seal!

    Reverse steps from 11 to 1 to re-assemble your axle assembly.

    Be sure to check your differential oil level once you are done. These axle bearings are 'wet bath' and they get their oil from the differential in lieu of using axle grease.

    If your leak was bad, be sure to clean up the emergency brake shoes and drum area before re-assembling.

    Looking back, I WISH I had taken pictures of this process since I could not find any to assist me while doing my research. Feel free to add any in your comments that may help others out.

    Cost of this repair $19.98 for oil seal, 2 cans of brake cleaner $4.95 each.

    Shop estimate to have this done $199 labor, $50 parts, $30 shop supplies/disposal fee.

    Huge savings and a pretty simple job for a DIY.:happy:
    Chesters and nvestysly like this.

    DAREDEVIL Rockstar 4 Years 1000 Posts

    YEP, that is how i did it as well. Only i paid $12 bucks for oil seal at NAPA !
  3. Crawdaddy

    Crawdaddy All hail the Mad King!! Staff Member 5+ Years 1000 Posts Platinum Contributor

    Good job. I only have a couple things to add since I've recently rebuilt my hubs on my full-float 14-bolt axle.

    First, some people have drums, and they come in 2 different flavors. Early 14-bolt axles (let's just say pre-95ish) and duallys have the drum behind the hub and are attached to the hub by the wheel studs. Later 14-bolt axles came in both disc and drum flavors, with the drums on these in front of the spindle to make replacing brakes easier. For the drum models, there's no caliper to remove and hang off to the side, but you do have to back the shoes off. No big deal.

    Second, the proper way to remove the hub nut is with an 8-pronged hub nut socket. The socket might be listed in stores as for 1-ton Chevy truck axles, GM Corporate 14-bolt axles, or Dana 60 axles, since the Dana 60 hub nuts are the same. I think I paid around $20 for mine, and if you tear into at least 2 hubs, (1 axle) it's worth it. You also need it to correctly reset the bearing preload when you reinstall the nut. I've taken the hubs on and off my 14-bolt axle several times already, and have used it on my uncle's 14-bolt dually axle too.
    Last edited: Feb 21, 2011
  4. o3gerber

    o3gerber Rockstar 100 Posts

    nice post wish i had this the first time i changed my bearing and seal, ended up poping off the diff cover just to relize i dident need to
  5. Irrigator

    Irrigator New Member

    Nice post! I am glad you made the point about preload. I am about to change the seals on mine and would have totally skipped that part. What is the prelaod for a 14 bolt corporate 4.10 with G80?
  6. Crawdaddy

    Crawdaddy All hail the Mad King!! Staff Member 5+ Years 1000 Posts Platinum Contributor

    I'll have to go home and check the specs, but I'm fairly sure the spindle nut preload is to torque the nut to 50 foot pounds while rotating the hub and then tighten it up until the next groove lines up so you can put the key back in.

    For more than you probably ever wanted to know about the 14-bolt rear axle, check out the 14-bolt bible here:
  7. I really like your site. Excellent content. Please continue posting such profound content.
  8. ffcapdilla

    ffcapdilla New Member

    I have the same issue with 04 2500hd rear axle leaking. I tried it myself, following the same instructions, however when I went to put the seal back on I could never get the seal to seat properly. I rented the seal tool at hardware store and still could not get get it all the way one. I put it on as far as it would go and then put the locking nut back on, reassemble and still leaked. I took it to a shop and paid 300, and it still leaked, took it back again to different shop same company and still leaked. Just wondering if anyone else has had this problem with rear axle seal leaking? I would like to try it again with some help on how to get that seal seated properly.
  9. donl

    donl Rockstar 100 Posts

    When my Dad had a shop (30 years ago) we would gently take the paint off the new seal before installing.
  10. o3gerber

    o3gerber Rockstar 100 Posts

    ffcapdilla, i have had the same propblem with both of my 2500's the same seal on both and i have yet to figure out how to get it to stop leaking, have you made any progress on it yet?

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