*(This is with the understanding that the vent is clear and the bearings are still good)

Theory: the retainer is not making contact with the seal correctly and allows oil to leak past.

Observation: my seal when seated in the housing all the way in,would ride right on the bevel edge of the shoulder of the retainer. Any wobble would let oil get by the seal. The retainer had a polished ring near the edge. You can see the ring next to the bevel in the top photo (reference post #23)

Solution: I just re-did the seals for the forth time in 3 months. I found that no matter how I installed the seal it didn't sit on the retainer far enough. I even tried the Timken seal 1960 but the rubber was too stiff and it failed in two days. Its a crappy seal, stick with oem. My solution was to install new retainers backwards so there is more of the shoulder for the seal to ride on. I also moved it inboard by 1mm plus the 3mm i gained from not having the bevel there anymore equals an extra 4mm of shift in placement. If you go more than about 3mm inboard with the retainer, it will rub the housing. So 1mm is all i wanted to move it. By doing this, it will allow you to seat the seal all the way into the housing squarely. Here's a couple of pics.

Old config



New config


5/04/2012 158,000 miles -installed
5/27/2012 still dry
6/28/2012 still dry
7/19/2012 still dry not a drop of oil leaking. Its been 2000+ miles and this time I ran a ribbon of cheese cloth around the ABS ring and it came up dry.
9/15/2012 still dry
10/15/2012 still dry
02/13/2013 Continued success. 166,500 miles on the odometer, 6,000+ from time of the repair
6/15/2013 still dry @ 169,500 miles.
3/1/2014 still dry @ 177,500 miles.
7/10/2015 still dry @ 194,000 miles.
6/10/2018 still dry @ 226,000 miles.

Note: At this time I believe I have proven this to be a viable solution to our leaking axle seals. I won't post any more updates unless it leaks. Otherwise, consider it sealed. Its up to you now to decide how much $ you can afford to spend and how many times you desire to do this job.

...So far so good. When I say still dry, I physically remove the wheels and remove the ABS sensor and check in the cavity for oil. I am not waiting for it to spill onto the brake shoes. (See post #51)

When you install the axle, MP grease the seal and put some gear oil on the retainer and be careful inserting it into the seal. Dont force it. Once it lines up it will slip into the seal nicely. The retainer's edge does have a mild radius to it so it won't damage the seal. You will know that you are in the sweet spot if you feel the resistance of the rubber seal 3/16" before the bearing carrier plate mates up to the axle housing. That will put you dead center on the retainer.


* don't assume the original inner retainer is in the correct position. If your axle vent is clear, it probably wouldn't have leaked if it was positioned correctly. I would suggest before disassembling the axle, install a new seal in the housing and test the position on the retainer with grease to make sure it will be correct. I used the new retainer to check how deeply it could be set into the seal. It turns out that the retainer bottoms out on the housing before it will flush up with outside of the seal.

I have read discussions of only partially seating the seal so it sits on the retainer better. I tried it and I personally couldn't get the seal to square up properly.

I think this may well be the solution to this problem.

Feel free to share your thoughts.

Attached Images

   

This is an image taken from the TSB regarding the seal redesigned in 2003. If you notice the old seal had a long flat contact patch which would sit upon the shoulder of the retainer extending all the way to the outer edge of the seal. In the newly redesigned seal, they changed it to an angled contact point, but that contact point is too far inboard (now near the inside edge of the seal) and rests not upon the shoulder but on the retainer's bevel.

This could explain why even new seals are failing simply because they aren't seating on the retainer's shoulder. The TSB link is below the picture.



Axle seal TSB

Attached Images

 

Side by side comparison of seals. OEM, National and Timken

Glad you seemed to have fixed the problem you were having, and I applaud the enthusiasm. I didn't realize this was really a problem. I know the axle seals eventually leak, and I replaced mine when I did my 180k suspension overhaul. It was a simple process, and I'm at 199k now I've not had a leak since then.

I would caution others that try this method that the bevel is most likely there to help you not tear the seal during insertion of the axle.

I'm glad it worked as it was supposed to for you. We should all be that lucky. I'm always curious though when someone says they don't have a leak after fixing their seals. Is that because the oil isn't draining down the wheel (yet)? Or did they actually pull the ABS sensor out and physically check for the presence of gear lube. The oil can pool in the space between the inner and outer seals for a good long time before it will be forced out into the brakes, usually due to the vent being blocked. If the vent isn't blocked, the oil may not exit onto the brakes for thousands of miles.

Can I ask you, did you look for oil in the axle housing or just haven't seen it on the wheel yet? Its a 5 minute check and you don't need to lift the truck or pull a wheel off to do it. Just roll underneath, pop the sensor and dip something into the bottom.

*I made the video to show that the chances of tearing the seal are nil. Honestly, when you buy the parts, try it on the bench and see how easy it will fit into the seal. I realize this is unorthodox and I am not telling anyone to do it. This is what I did and why? Maybe someone else can learn and benefit from my experience.

While I applaud your effort to document this, the method seems very strange coming from someone who supports OEM engineering with such fervor. Toyota didn't screw this up, did they?

Sorry to rehash the past, but come on!

The OEM seal and the bevel on the retainer look mated for each other to me. I can't imagine not putting it in bevel-side first, given the obvious relationship the two parts have.

But, all the same, let us know how it goes.

Well that's a good point to bring up. Keep in mind the seal was redesigned, not the retainer. So you have the old retainer with a large bevel designed for a flat seal being used with the new seal. The new seal's contact point is deeper within the housing just outside the bevel. If your seal mates up properly, that's great. With all the failed seals, somebody should rethink the design. I'm just working with what is available to me.

The new OEM seal design allows for a lot of flex. Even with the retainer big side in, it goes in easily. This wouldn't work as well with any other seal like Timken or National brands.

This is actually a really good idea to try. And well done with the video. Hopefully this setup works great and we end up with a good fix that's as simple as reversing the direction of the retainer ring.

Do you happen to have the OEM part number for new retainers?

The retainers are unchanged from what I understand. 42423-20010. I saved some money by removing the old retainer with a dremmel using a cut off disc, chisel and hammer. It only took a couple of minutes each. The shop just had to press on the new ones. Measure carefully before you make changes and verify where your "new" installed seals will sit before you cut them off. Now you can seat the seal all the way home.

Compare the non-ABS axle to the ABS axle housings and you will quickly notice that the seal of the non ABS protrudes from the axle housing and is pressed right up against the bearing. That means that if your seal is not pressed right up against the ABS exciter ring, the seal is not sitting on the retainer. But you cannot just push the retainer deeper into the axle housing because it will rub the housing.




* Pay special attention to the seal above in the non-ABS axle housing. It protrudes from the housing and seats against the bearing when bolted together.



Clearly you can see when you view through the ABS sensor hole, the seal is nowhere near the ABS ring.

Simple math:
The seal is 9mm thick
The retainer is 13mm thick but the shoulder is set back 3mm so the shoulder is 9-10mm across. For the seal to contact the shoulder, the retainer must be flush with the outer edge of the seal (not possible) just to make the proper contact with the mating surface. In the original configuration, the red line would therefore neccessarily need to be overlapping the yellow line for a proper seal to be affected.

For reference, the sensor holddown bolt hole should be 6mm across.

The picture below should make this more clear.

For the people who may want to tackle this DIY and are not sure what the grease test is, here is a picture another forum member provided to me (since I forgot to take this picture when doing mine). Mark tells me he left 3mm of the polished axle inboard of the retainer and once installed, using grease on the retainer and spinning it a few times, it will leave a foot print of where the seal lip is positioned. Note, the bevel is outboard and the retainer shows the seal riding in the center of the retainer, right where it needs to be.



*When you take your parts to a machine shop, consider printing this picture and bring it with you.

To take this one step further. If you were to only push the retainer inboard as shown but keep the bevel oriented inboard this picture shows where the seal will seat represented by the black line, at best. Not ideal by any account.



And if you place the retainer where the FSM tell you to, the black line would be on the bevel and the seal will leak.

Your Logic seems sound, I will keep this in mind if/ when i have to change my seals, Thanks for your efforts in this write up

10/15/2012
* not a drop of oil leaking. Its been 4000+ miles and this time I ran a ribbon of cheese cloth around the ABS ring and it came up dry.

I have a question. I recently pulled axles to install locker.

Should your axle shaft have any play up/down/left/right while attached to hub assembly? (I could move the axle shaft in all those directions while it was out of the truck and connected to the hub). Didn't seem right to me, but I have never had them out before.