rear diff housing bent?
 

i have a 2002 tacoma. my right rear axel has been leaking so i got the seal fixed. a day later it was leaking worse. the shop waranteed the replacement seal of course. the seal keeps leaking so we replaced the axel thinking it was bent but that didnt solve the problem and now both sides are leaking and the break pads wore out very quickly. they now believe it must be the diff housing thats bent so they want to send the housing out to get straightened. truck drives great with no wobble or any signs of things being wrong other than the leak. any other thoughts at what this might be?

You made sure your vent was not plugged ??

How much is this getting the axle straight going to cost ??

Just how did you bend your axle ??

ya, i took the vent hose off and its clear. the shop quoted me at $1200 to dissassemble the rear diff. send it to the shop to straighten it, and put it all back together. i bought the truck with a little damage to the front right bumper so its possible the previous owner hit something hard in that side

If the Tacoma axle seals are the same as the 3rd gen axle seals, then it could simply be a bad seal installation. I've owned my 4Runner since new and have replaced one or the other rear axle seal 6 or 7 times over the years. Absolutely maddening when you take great care to ensure the seal lip will ride in the middle of the spacer ring - and then it starts leaking again months or a year later. It is truly a piss poor design, that, coupled with drum brakes, makes for the most frustrating aspect of a truck that I obviously love (399,000+ miles....).

I have used Mobil1 75w/90 synthetic gear oil in the rear diff, front diff and transfer case since new (change every 50k miles). About 30,000 miles ago I was faced with yet another dripping backing plate. Frustrated, I drained the Mobil1 and refilled with run of the mill Valvoline 85/w/90 non-syn oil. I just had the drums off last week to clean & check the brakes - the seals showed no signs of leaking. I dumped the oil and gave the diff a fresh fill of Valvoline 85w/90 non-syn and expect things to stay dry from here on out.

While the transfer case & front diff have never leaked with Mobil1, I am firmly convinced that a synthetic gear oil in these rear axles is incompatible with the Mickey Mouse seal design used.




Andreas

klank, if your rear axle housing is bent it will show up on an alignment. Don't fork over your hard earned dough without them proving to you that it's bent! The same goes for the axle, you should be able to spin the axle and see if the wheel mounting flange wobbles if it's bent. It really sounds like they did a piss poor job of replacing your seals and now want to do a better job of emptying your wallet.

yes, the whole thing sounds a little fishy to me as well. they haven't found anything wrong with the alignment so they are suggesting that it is only a slight bend that they can't visually see but suggesting that the shop doing the diff housing straightening would be able to tell and they have replaced the axle seal 4 times now within the last year. once it lasted a day. once it lasted about a week, and once it lasted a few months. the first few times it was literally drooling out of my rim. but now it's only a very slight leak but is now on both sides as well as the main diff seal.. so perhaps i need to find out what kind of oil they are using and suggest a non synthetic? or perhaps say screw their warranty and bring it somewhere else but that means starting from scratch at a different shop unless there's something that i'm still missing that could be wrong or bent...

When a complete used axle housing could be had far cheaper .

It makes no sense to try and get something back to straight that is so slight you can`t see it .

Every Housing I ever saw cracked before it bent !!

Swap a used housing in and tell you your original was sent out and fixed ??

Who knows

What type of seals are being used, I would use OEM here and use silicon around the outer surface, maybe you need new bearings, but I assume the used axle they tried had a better bearing than the last axle, check the surface of the seal ring that it rides on, like mentioned you can put the seal in a few different locations you don't have to drive it all the way in but it must be driven in perfectly squarely, the seal ring on the axle is replaceable, I have also seen examples of when the Dealer removed the ABS and seal ring and cut into the axle requiring JB weld to seal between the ring and axle shaft, the ring could also be in the wrong location if replaced, also you said the vent tube was clear, so you have an extended breather hose, I would double check it is clear at the diff and breather aswell by blowing into it. Doubtful the axle housing tube is bent. If they do swap diffs make sure you got the right ratio, it is stamped on the outer edge of the ring gear.

Here you can see the angle grinder marks from my local Toyota Dealer, I asked them to press out the old bearing and press in the new bearing as I would do the rest and had no press that could handle the long axle, little did I know until I got home they grinded off the ABS and seal ring, I bitched and they blew me off, so I added JB weld to the surface before installing the ring, no leaks afterwards, but I was still unimpressed.
https://cimg6.ibsrv.net/gimg/www.yot...e03135ff54.jpg

The axle vent has already been mentioned, it would be my prime suspect. If it can't breathe, it's going to push oil out of the seals.

If it's anything like the 3rd gen 4Runner axles (with ABS) then there's a very un-intuitive air gap in the things that need to be pressed onto the axle when the bearing is replaced. Pretty much every other press fitting I've ever seen has all the components pushed together. If there needs to be a gap, they have a spacer. But on the 3rd gen, there needs to be an air gap between the replaceable sealing 'ring' and the ABS sensor and bearing.

If the seal ring is pressed in all the way, as it would be common to do when looking at the parts, it won't reach the seal in the axle housing.

You can check this easily by smearing grease on the seal ring, and then installing the axle shaft into the axle housing, all the way in. Then pull it back out and the grease will show where the seal is riding.

We had this issue with my wife's '96 when a machine shop right across the street from the Toyota dealership, that said they do lots of wheel bearings for the dealership, pressed the seal sleeve all the way on. It leaked. Replaced the seal. Still leaked. I finally measured things and realized the seal was sitting some slight distance away from what it was supposed to be sealing. We took out the other (untouched) axle shaft and saw the gaps between the installed parts there.

Warranty or not, if they can't get it right in 4 tries and just decide they need to throw more parts at it or assume you have a bent axle housing you are probably going to the wrong shop. The right shop will figure out what is going on and provide proof if you need major components, mysterious drivability issues sometimes come down to good guesswork, but not leaky seals. Did you buy the truck and a service warranty from crazy pete's used cars or something? Or do these guys supposedly know Toyotas?

You might be having issues with the ring not mating with the axle seal. Toyota redesigned the axle seal which moves the sealing point a few mm away from the original location. Here are a couple of videos that should help. One is focused on ABS and one on non-ABS axles. The maker of the video, Tim, is the leading expert on the Toyota axle seal issue.

Be nice to know how this played out??

I'm sure we all know what was the issue was, doesn't take an expert to stop oil leaks from an axle seal but it does take a keen eye and a good quality seal.

turns out we think it was the seal not being installed correctly for my truck. the shop i had taken it to just sent out the seal to be pressed by another company so im guessing they didnt know what vehicle they were installing it for. took it to a specific rear end shop and they helped solve all the problems. i appreciate all the input i recieved on here! helped tons :)

I'm glad you didn't throw away $1200 to have your housing straightened

holy crap, right??!!! great success

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