When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I went to replace my axle seal. I thought it was a simple matter. removed the caliper, removed the 4-bolts holding the axle retainer, got the slide hammer out, pulled out the axle. no problem.
I notice that the seal is outboard of the bearing, and won't slip over the bearing. The bearing is held on by a pressed-on machined steel ring retainer. The shop manual says to get out a cold chisel and split the retainer. it looks like solid steel, about 3/8" in thickness. of course, I wasn't anticipating that, so I didn't have a replacement on hand, only had the seal. the GM manual says to not reuse this bearing retainer, nor the bearing. Obviously, if a chisel was used in the removal, then it's rendered not usable, period.
I was figuring I could put the axle in a hydraulic press and press the bearing and retainer off, and reuse at least the steel retainer, but wondered if there was some unique unknown characteristic of the retainer ring or installation process that made it a one-time use only. like, if you press it off, then it gets ruined? or damages the axle?
anybody else run into that?
not having a good solution, I reassembled the axle into the rear end, and will defer this project until I get all my ducks lined up in a row. more research...
i just did that to my car, the bearing has to get pressed off and when you do that it completely bends the bearing out of shape from the amount of force needed to remove the retainers .If you were just going to change the seals you might as well change the bearings because the retainers have to get pressed back on.when you buy new bearings the retainers come with them.
The steel retainer comes with a new bearing so no need to save them. The best way to get the retainer ring off is with an air grinder. Once you grind down far enough it'll just crack and slide off.
For the bearings and seals, go to Autozone and order two #Set9($14.99ea)(bearings) and a #710179($10.99)(passenger side seal)... for the driver's side seal, go to Napa and order a #16491($17.49).
The reason for ordering the driver's side seal from Napa is because the Autozone/Timken seal is wrong(at least in my case it was) It was all metal on the outside, with the green paint. They should both have rubber outsides. The problem was that the seal stuck out and bent the retainer plate before we realized it, and it seemed to fit very sloppily, but the Napa seal fit and worked good.
Autozone is cheaper for the other stuff by a few dollars. Would hate to see someone else go through the same trouble as we did, lol.
I was able to get a bearing, the Timken SET9, and it came with the bearing retainer.
so I pulled the axle out again, used the grinder to work on the old retainer, only when it got down to about 1/8" thickness, then the cold chisel was able to fracture it so that it would slide off. Surprisingly, I still had to use a hydraulic press (HF 20-ton) to get the bearing off, and it did take a lot of force to get it off. I used a bearing separator between the seal and the bearing. bearing separator resting on arbor plates. axle flange below arbor plates. press set up for "tall" mode, presses on differential (splined) end of the axle. when the axle bearing assy breaks free, the whole axle drops. suddenly. so you want to have something prepared for that. I noticed the removed bearings were Timken's, made in Australia, FWIW.
I used a strip of 600 grit sandpaper to clean off the slight surface rust from the oil seal wearing area, and to remove the slight burrs incurred during the bearing removal.
before reassembly, since the seals are unique to the left and the right, I checked that I had the correct seal for that side of the car, and the part number on the removed seal did match the part number on the new seal.
I straightened & reinstalled the retainer plate, installed the seal with grease, and then pressed the bearing and retainer on with the hydraulic press, now reconfigured for "short" mode. that was a really tight fit, a lot of hydraulic force (again!) to get the bearing to bottom out. I did check the assembly at least 3X to make sure I had the bearings on right since that sucker wasn't coming off once it was installed. The Timken retainer didn't have a chamfer like the factory retainer, it doesn't seem to make a difference. maybe I shoulda used moly lube (instead of synth grease) to help the bearing get press-fit onto the axle better, sometimes that helps.
after I reinstalled the axle assy (before tightening the 4 retainer plate bolts), I gave it a couple whacks with the hammer to seat everything fully (since it came off with a slide hammer).
still yet, the retainer plate was very slightly arched when the 4 bolts were snugged down, I'd say maybe 1/32 inch. however, I couldn't remember if before I removed the assembly, if that was a pre-existing condition. maybe next weekend I'll look at the other side. for this drill, I was only doing the RH side since it was seeping lube slightly.
sofar, I've driven it and it seems to be fine. no rattling, no weird noises, accelerating straight & around corners seems fine.
I also used this opportunity to install the TA diff cover (#1802), it's a very nice piece. I had to spot face the bearing caps as alluded to in the instructions for the load bolts. the xerox picture in the instructions wasn't very clear. The diff bearing caps have a non-trivial casting protrusion which has to be removed to provide a flat area for the load bolts to set. The bearing cap bolts are 3/8-16 thread. The studs that came with my kit were 7/16". probably a packing error. oh well, so I had to reuse the bolts.
For the bearings and seals, go to Autozone and order two #Set9($14.99ea)(bearings) and a #710179($10.99)(passenger side seal)... for the driver's side seal, go to Napa and order a #16491($17.49).
I have used standard metric axle oil seals. Seal dimensions are 42x65x8(mm) and DIN standard 3760 type AS (I think that the better-known type of seal in US is TC). Material: NBR. They work well on both sides.
The steel retainer comes with a new bearing so no need to save them. The best way to get the retainer ring off is with an air grinder. Once you grind down far enough it'll just crack and slide off.
For the bearings and seals, go to Autozone and order two #Set9($14.99ea)(bearings) and a #710179($10.99)(passenger side seal)... for the driver's side seal, go to Napa and order a #16491($17.49).
The reason for ordering the driver's side seal from Napa is because the Autozone/Timken seal is wrong(at least in my case it was) It was all metal on the outside, with the green paint. They should both have rubber outsides. The problem was that the seal stuck out and bent the retainer plate before we realized it, and it seemed to fit very sloppily, but the Napa seal fit and worked good.
Autozone is cheaper for the other stuff by a few dollars. Would hate to see someone else go through the same trouble as we did, lol.
So this one from Autozone (driverside) is incorrect?
That seal sort of works, but it isn't "correct". I used one in my car, but you have to space the retainer plate a bit since that seal sits much too proud of the end of the axle end
I haven't looked in a while, but I don't think you can get the correct seals anymore
Looks like Yukon sells correct seals, pricey though
RH YMSG1002
LH YMSG1001
That seal sort of works, but it isn't "correct". I used one in my car, but you have to space the retainer plate a bit since that seal sits much too proud of the end of the axle end
I haven't looked in a while, but I don't think you can get the correct seals anymore
Looks like Yukon sells correct seals, pricey though
RH YMSG1002
LH YMSG1001
This is super crazy man. I cant believe that parts for our m78 are rare and expensive.
This is super crazy man. I cant believe that parts for our m78 are rare and expensive.
It was a 3 year(?) run for the cars here, it's not surprising parts are not readily available. Our cars are also, at minimum, 28 years old. There isn't as much a market for any of the parts. Count your lucky stars
Im also using that AZ seal and it does protrude slightly past the axle, maybe 1/16th tops. Are the ID and/or OD sizes different? I believe the width is, correct?
Im also using that AZ seal and it does protrude slightly past the axle, maybe 1/16th tops. Are the ID and/or OD sizes different? I believe the width is, correct?
Im also using that AZ seal and it does protrude slightly past the axle, maybe 1/16th tops. Are the ID and/or OD sizes different? I believe the width is, correct?
First seal is definitely wrong. Second seal might work, but need to see the top of it to be sure. I actually have the SKF seals that are correct, that MIGHT be the right one. Third seal is definitely correct, just expensive
First seal is definitely wrong. Second seal might work, but need to see the top of it to be sure. I actually have the SKF seals that are correct, that MIGHT be the right one. Third seal is definitely correct, just expensive
Second seal also looks alot like the AZ piece.The side shown also looks the same, maybe the top side does too.
This is such a great thread. I currently had seals put in, the flange was cranked down and is now bent. I originally took it in because the driver’s side was leaking (likely because it was overtightened with the wrong seal in it). I’m working through gremlins on this car, it has an Eaton 3:45 and I wasn’t comfortable doing it myself. Now I’m just annoyed it wasn’t done correctly not once but twice so I’m just going to do this myself and learn. I wasn’t sure if the lash needs to be reset after axle removal? Anything I’ve read or watched points to ‘no’
I’ll check out those Yukon part#’s. I’m new here and grateful for this information.
The steel retainer comes with a new bearing so no need to save them. The best way to get the retainer ring off is with an air grinder. Once you grind down far enough it'll just crack and slide off.
For the bearings and seals, go to Autozone and order two #Set9($14.99ea)(bearings) and a #710179($10.99)(passenger side seal)... for the driver's side seal, go to Napa and order a #16491($17.49).
The reason for ordering the driver's side seal from Napa is because the Autozone/Timken seal is wrong(at least in my case it was) It was all metal on the outside, with the green paint. They should both have rubber outsides. The problem was that the seal stuck out and bent the retainer plate before we realized it, and it seemed to fit very sloppily, but the Napa seal fit and worked good.
Autozone is cheaper for the other stuff by a few dollars. Would hate to see someone else go through the same trouble as we did, lol.
For the 9 bolt rear axle:
My 9 bolt 3.27 gears was originally from an 87 GTA with rear disk brakes (non pbr).
The bearing set at autozone is now called set 9AZ, works great. Oriley's part number is Set A9 and they sell master pro and precision brands.
The left seal at autzone is part number 30267 and comes in a bag labeled yukon ymsg1001
The right seal at Autozone is part number 710179 and comes in a bag labeled yukon ymsg1002, napa part number is still 16491.
the 20 ton press and Autozone rental tool bearing puller part number 57381 8065 and will take off both the bearing and collar without damage if you get it behind the inner bearing section properly. I had to build a 6" x 6" 3/16" thick steel plate box to give the axle face room to move down while the bearing puller stayed stationary on the box.
The new collars are a little taller but dont interfere with anything. Everything went back together like a glove.
Last edited by polygaryd; May 1, 2026 at 08:43 PM.
the 20 ton press and Autozone rental tool bearing puller part number 57381 8065 and will take off both the bearing and collar without damage if you get it behind the inner bearing section properly. I had to build a 6" x 6" 3/16" thick steel plate box to give the axle face room to move down while the bearing puller stayed stationary on the box.
The new collars are a little taller but dont interfere with anything. Everything went back together like a glove.
Do you have pics of this steel “box” that you made?
Do you have pics of this steel “box” that you made?
The welds suck, using a 110v flux core welder outside in the wind and I'm a very novice welder just fyi. I made mine 6.5" ID but 6" is all that is needed to clear the axle face Ideally it should be 3.5" or 4" tall but i got this from home depot as a 3ft piece of flat steel. It was the widest piece they had. The steel was to replace this wood that wasnt strong enough to do the job.
Last edited by polygaryd; May 1, 2026 at 11:05 PM.
If youre about to do this, push the seal as far away from the bearing towarse the axle face as possible, you can barely get the bearing puller in between the seal and the bearing. Then make sure you tighten the bearing puller pretty tight, and align the axle flange as a diamond shape to the bearing puller. Then use the big v cut outs on the black press steel plates to form a diamond shape so that you don't bend the axle flange when pressing off the bearing. It took two people to get the axle in there and aligned and supported.
I ruined the first bearing because I had the bearing puller under the cage and not the inner lip of the bearing. You can barely see the inner lip of the bearing vs the hard shoulder of the axle. The second one came off as one unit that could probably be used again. Sorry I dont have more pics. If you want to/ need to send pics, I can mark them up as to how to align or where to place stuff.