tns1

This has all been documented before, but there may be one or two things here worth reading.

The parts I purchased:
Two new bearings
Two outer seals
Three inner seals (one destroyed)
Two axle orings
Two retainer rings
One Abs rotor

Aside from the normal tools I used:
A good circlip tool.
A dremel with various cutoff wheels "just in case".
Some homebrew tools to take the place of the press and SST.

My bearing driver is, I believe, a piece of 1.5" galvanized steel water pipe 26" long. It fits perfect. Mine was used so I had to take a grinder to the inside to a depth of about 4" to remove some scale. I used this to drive on the bearing, abs rotor & both retainers. It works as well as a press if you are careful. You want the driving end to be as true as you can make it. If you buy a length at Home Depot, they can square the end for you. For my used pipe, I used a hacksaw and a file to true it up.

My anvil is a round slug of steel I had laying around. I am not sure where you would find such a thing but it is a good diameter for setting the axle on end when you drive on the new parts.

I destroyed one seal trying to use a generic seal driver (round plate with 6" central handle). You have no control with that short of a handle, and you will end up with a crooked seal. My seal driver is 2" ABS plastic pipe 2ft long with a 2" FIPS fitting (the one with knobs on the OD). This is still a bit smaller than ideal, but far better than that generic driver. The long pipe gives you better control to keep the seal flat. The only thing better would be a sleeve turned to closely fit the ID of the axle tube, but you would need a lathe and a 2" steel pipe coupling to make this.

Update 2/27/2013 1000mi - no leaks, sensor (and new brakes) are dry
Update 2/26/2014 11500mi - no leaks, sensors (and brakes) are dry
Update 9/28/2014 18000mi - no leaks, sensors (and brakes) are dry
Update 6/12/2016 30000mi - no leaks, sensors (and brakes) are dry
Update 9/25/2018 50000mi - no leaks, sensors (and brakes) are dry - no need for further updates, it clearly works
Update 5/5/2021 75000mi - Spoke Too Soon. Both ABS rotors wet with oil (but shoes still dry). Replaced SKF seals with OEM.

tns1

Once I pulled the axle assy out, I set it upright on its lugs and used a steel rule marked in 0.1" increments to measure the distance from the edge of the bearing outer race to the furthest face of ABS rotor. The rotor has three or four small but distinct steps on its face. I am talking about nearest the teeth. The magic number here is 1.4" exactly. I tried to match that during re-assembly.

I looked into the axle tube to inspect the seal, and used the steel rule to measure the depth of the seal face from the end of the tube. The number here was very close to 1.5". Essentially this means that near the OD of the ABS rotor, there will be about 0.1" clearance from the seal face. This is not real important, it just shows there is some margin for error in getting the final positions.

The things that control where the seal lip rides on the inner retainer, are the type of seal you buy, how far you drive it in, and the position of the inner retainer on the axle.

As the bearing wears it may develop axial play up to 0.050" or more, so you really want the seal lip to ride as close to the center of the retainer sealing surface when you put it all together. You cannot control exact placement of these parts without better tools, but as long as you go slow and measure as you go it will be close enough.

The seals I purchased were SKF. These are a tad narrower than the National, and could possibly be driven further into the axel tube resulting in a slightly different fit.

Getting the axles apart and driving in the new seals are the most difficult tasks. To separate the axles I used the method, "slam the axel end against either concrete or a steel plate". This will destroy all but the toughest concrete, so spare your garage floor. Make sure to move the retainer clip out of the groove BEFORE you try this!

I used my large round anvil as a target, and it took 15-20 good smacks to separate the first axle. If you are lucky, the brake assy/bearing housing may slide over the bearing as you do this, and act as a slide hammer.

As tough as these axles are, all this pounding distorts the axle end a bit. I used the edge of a rectangular file to dress up the very end of the splines. It didn't take long, but is one drawback of this method. You will want to test fit the axle back in before you mount any new hardware, checking for spline damage.

Once apart, I wiped down and oiled the surfaces of axle & bearing and using my bearing driver to hammer the bearing home. As the bearing approaches the bearing housing, I inverted the axle, bearing driver and anvil, balancing it all on another hard surface, and pounded directly on the anvil face. This lets the brake assy/bearing housing slide partly down over the bearing and prevents it from getting crooked.

Once the bearing was in place, I squeezed the retainer clip a bit to shrink it down and placed it in the groove. I then hammered on the ABS rotor very slowly to achieve the same 1.4" dimension as the original.

At this point I took a series of measurements with micrometers to convince myself that I should mount the inner retainer backwards (bevel end facing ABS rotor) to optimize the seal/retainer placement. I pounded on the inner retainer very slowly, intentionally leaving a gap (~0.05") from the ABS rotor.

I removed the old seal, and destroyed one new seal using a generic seal driver. Once I build my new seal driver from ABS pipe, I carefully (and successfully) drove in a 2nd new seal. The National seals can probably be driven in as far as they will go. With the SKF, I tried to get the seal face to the depth of the bevel in the axle tube bore, but ended up slightly deeper. With 0.1" clearance, the exact depth matters less than keeping it straight.

I took a black marker and made several lines across the retainer sealing surface, and test fit the axle. Pushing it all the way in and spinning it around left a distinct wipe mark on the black markings (much better than using grease). It was easy to tell from the wipe mark that I should drive the retainer all the way until it touched the ABS rotor (carefully!).

Repeating the measurement shows it was almost perfectly centered, so I finished that side.



The second axle was not cooperative. 30 or more hard whacks only moved the bearing and outer retainer. I was afraid of damaging the splines too much, so I finally wrapped the axle in duct tape and used my dremel with a few cutoff wheels to grind a deep slot across the retainer. I used a cold chisel to crack the thin material that was left. I still could not get the ABS rotor to budge, so I cut that off too ($55 at Toyota).

I spent a good deal of time restoring the splines before the axle would fit again. Would have been nice to have the SST for this.

The rest of the assembly went as expected.

I'll replace my oil soaked brake shoes after a week or two of no leaks.

DRCOFFEE

The last time i did my seals i bought National, Timken and OEM and the OEMs had more room for axle play. I think you may find the brand you used will overheat and fail pretty quickly. Pull the ABS sensor and check on them.

tns1

The SKF seal has only the single lip, so I don't see any issues with reversed retainer installations. After destroying a seal, I did buy one of the National seals before also buying another SKF, but didn't think to compare them side-by-side like you did. Like the OEM you show, the SKF should tolerate a fairly large misalignment during assembly without risk of damage. When you think about it, the retainer is 0.512" thick, which is more than the maximum engagement with the seal. The lugs are much longer than this, and will be engaged long before the seal comes close to the retainer. So the maximum misalignment all comes down to the amount of slop between the lugs and the clearance holes in the flange (worth measuring but probably less than 0.050").

This amount of slop may be enough to cause problems with the Timken seal/reversed retainer situation (folding/tearing of the dust lip). If the National seal is as stiff as you say, it may have a smaller opening in the encapsulated metal shell, and so it may be possible to deform that metal shell during axle install, but that seems unlikely. Pictures of a damaged seal would of course be ultimate proof.

I did note that my old OEM seals had lost all of that flexibility and barely contacted a retainer I slipped in by hand. Its not hard to see how oil could leak by with any amount of bearing slop. I did remove & check my breather fitting.

I would not rule out the possibility of installing the retainer in normal orientation but with a gap to the ABS rotor. With the worst case (deepest) seal install it is still possible to push the retainer all the way to the seal face without striking the axle tube inner lip (I checked). There may be less leeway to work with here, so I would still opt of one of the single lip seals and a reversed retainer.

I hope you are wrong about the longevity of the SKF. The seals get drenched with gear oil, so I'd think the only things that could shorten the life would be axle wobble and riding off the polished surfaces of the retainer.

The synthetic oil question is worth answering (for the OEM seals).

tns1

Disappointment!
On a recent check of my rear brakes, I found the shoes dry, but the ABS rotors are wet with oil on both sides. The SKF axle seals I used lasted only about 70k before leaking. Hopefully the reason for this failure is the rather snug fit these seals had when new. Too tight a fit may have caused damaging heat and wear as speculated above. I'll be pulling it apart to install the looser fitting OEM seals this time, but checking carefully for other reasons for failure.

Even with the seal driver I made for the previous repair, there was still a risk the seal was not perfectly placed during the initial taps of the hammer, which could damage the seal. I hope I can improve the tool to eliminate this risk. By chance, does anyone have an accurate measurement of axle tube ID just in front of the seal?

aowRS

^ 70k on your install before leaks is highly commendable. I've done this job numerous times on my '01 (currently at 478,000 miles). I gave up on synthetic gear oil for the rear axle a few years ago after dealing with repeated seal replacements. This, despite being super careful with measurements & install techniques.
It's now been a few years on the last installs & cheap-o Valvoline 80-90 oil. No leaks.

This thing gets used.






Andreas

Jomoka

Another thing to check is that the axle breather is not stuck or clogged. If it can't breathe through that, then it will breathe through the seals, and carry some oil with it.

tns1

Here I was thinking those seals would last until the new axle bearings wore out again, or at least over 100k. The fact that both sides started leaking at about the same mileage tells me its probably seal wear rather than anything I did wrong during install. One thing that changed during the 70k miles is I did drain and replace the gear oil, but I stayed with a non-synthetic. The breather tube was fine during the 1st seal replacement. I'll check again.

tns1

New OEM seals installed.

One thing I noticed when I removed the breather was a little puff of air. The breather has an internal check valve and spring, so if you blow thru it you must overcome the spring force. It isn't much but it guarantees there is always some positive pressure inside the diff, and weeping seals if they can't hold this small pressure.

There was nothing wonky about the old seals except the small puddle of gear oil that had excaped. The wipe mark on the retainer was dead center. I measured the axial play in the bearing with a dial indicator by pulling the brake drum in and out. Both sides were less than 0.020".

I made an improved seal driver on my wood lathe from a piece of 4x4. The top step is 0.350" tall and 1.900" dia, and holds the seal in place. The next step should be 0.300" tall and 2.750" dia, and is the driving surface. The remainder is 2.950" dia and then sanded to fit closely to the axle bore to keep the seal centered. This part needs to be at least 3" long. I used some wood sealer so the tool wouldn't absorb gear oil and swell up. This tool is much better than my prior one. No worries about the seal getting cocked in the bore. A few whacks with a rubber mallet and move on.

If these seal leaks are slow, one future idea is to drill a drain hole (with plug) for the rotor cavity on each side. You might be able to drain this area periodically and never replace those inner seals or worry about soaked shoes.