Hello all!
I'm new to this forum so I've still got a lot to learn here but by the look of things, this is a great place to be!
I've been a Toyota fan/owner for many years and although I'm not a mechanic, I have don a bit of work on Toyota's. I've run into a mysterious problem and I'm looking for some opinions that may carry a bit more experience than what I have.

I have a 1998 4Runner V6 Automatic Limited with 290,000km's. During the past 2 years, I've had to change the rear axle seals 4 times - both sides! This is not only costly but mysterious. The last mechanic to do the work was/is a 25yr Toyota mechanic but even he is stumped with this one! For experimentation purposes, he decided to repair one side only for the time being. He replaced both the inner and outer seals as well as the bearing on one side. I picked up the 4Runner when he was done and did not drive more than 15miles when I discovered that IT IS STILL LEAKING!!! The oil is running down the inside of the wheel coming out between the axle housing and the backing plate. My question is: what could be causing these continued leaks? Remember - BOTH SIDES are leaking although one side generally leaks before the other. The breather vent was checked during the last replacement job so that issue has been ruled out. Given the fact that BOTH SIDES leak at least in my mind rules out the possibility of a rogue faulty seal. All four replacement jobs have been done by reputable shops - the last one being a "Toyota man!" What in the world are we all missing here????? Every shop has told me that they have never encountered something like this before. Any thoughts?
- Could it be that the axles themselves are shot? Yet how could the diameter of an axle "wear" out if it is turning inside of a bearing?(The bearings show no signs of wear)
- Could it be that the axle housing itself is the culprit - resulting in seals and bearing not fitting tightly enough into the housing?

Oil can only be leaking through two places (as far as I understand) - either somehow down the axle column, or through the seams between the outsides of the seals and the axle housing itself.

Any thoughts would be greatly appreciated!
This is getting VERY expensive!!!!!!$$$$$$$$$$
Thanks!
Rod.

Check the axle shaft for excessive runout and or grooving at the seal location...

Here's a post on Tundra Solutions that pretty well sums up the situation.
http://www.tundrasolutions.com/forum...xle-fixed-3-a/

I just went through this about 4 months ago with a 2000 Tacoma. The mechanic I took it to (a guy at an independent shop that I know personally, and not a dealer), has seen this several times before on 3rd Gen 4Runners and Taco's of the same years, and says he has never had one come back. He agrees that the key is to use the re-designed seals, Toyota part 90310-50006. I would think that your "Toyota man" would know about that, but you never know. If you have part numbers on the receipts, check them.

Thanks guys for the info! THis gives me a place to start looking. I agree - this get's expen$ive!!!!!

Are you running OEM rims and tire size? I could see having those problems it different offset and huge knobby tires. I've seen several rice burners with the rims that stick out the wheel wells - sitting with only 3 tires along side I95 --- assume undue stress caused bearing to fail and disintegrate.