Cause of axle leak?

[RobertoX]

Hi Guys,

I've got a t series axle in my sprinter and am stumped as to why the LH axle has a slow leak. When I installed it I replaced the wheel bearings and seals and the LH side started to leak, just enough to drip down the back of the brake backing plate and put a few drops onto the inside of the wheel every now and then but other than that give no major grief.

So far I have replaced the seal (in case I fux0red the first one) and also checked the pressure relief valve on top of the housing for operation and it works. It still leaks is there any common problem that might cause this? slightly bent axle? stuffed bearing seal?

I hope someone can help, I hate leaks
cheers
Rob

[EVOSTi]

what can happen sometimes when you remove the old seal (usually with a screw driver) you can scratch the recess that the seal sits in. i have done this before on a customer car so just a small amount of oil can seep out from under the seal inbetween the housing and the seal.

[slide86]

perhaps you can put a real light smear of sealant ie threebond around the outer part of the seal, so that it seals in teh axle housing.

this would eliminate the problem that evosti has said about. it may fix it, or it may not. if it doesnt, at least you have eliminated one place it can leak from.

[RobertoX]

hmmm... will pull it out and have a look, I am usually quite careful but it is definately not unlikely (I'm pretty clumsy )

How did you solve it EVOSTi?

cheers guys

[love ke70]

yeah man, jus wack a little bead of high temp red, or blue rtv (any quality sealant) around the edge of the seal that leads in so it fills any imperfections in the housing

[Vios-GT_07]

had that problem with the S series diff in our sprinter.. went through 3 seals before it stopped leaking.. was under the warranty so didn't bother me but what happened was he used aftermarket seals.. the last seal he used was a genuine toyota item.... and i think he drained the diff and made everything dry, used a bit of silicone (i think it was), then put the seal in, waited for everything to sit in nicely before filling the diff again. Took 2 hours, but hasn't leaked since.. was LHS as well..

[EVOSTi]

yeah like mentioned the way i fixed it was to put some sealant around the outer surface of the seal. i just used some black silastic but most sealants would be ok. thats is if your problem is like the one i ecountered.
if not another thing that COULD but most likely wouldnt be the problem is sometimes the surface the lip of the seal touches wears away making a recess in whatever sits inside the seal be it a crank, drive shaft, cam etc or in your case an axle. when this happens you can either sit the seal out just a fraction or in further a fraction so it has something to seal on.

[Razor]

if your diff has a breather then that might be causing your axles seal leak, the axle breather might be plugged causing the pressure to vent somwhere else which is normally the axle seal

[RobertoX]

if not another thing that COULD but most likely wouldnt be the problem is sometimes the surface the lip of the seal touches wears away making a recess in whatever sits inside the seal be it a crank, drive shaft, cam etc or in your case an axle.

pretty sure its not this as the seal seals against the outside of the bearing and that is new

the axle breather might be plugged causing the pressure to vent somwhere else which is normally the axle seal

yeah that is what I thought at first but the breather works fine...


will chuck in a new seal and some sort of goo as soon as I get a chance

[oldcorollas]

doesn't the seal rub against the locking collar??
or does the bearing have an extended base for the seal to rub on?

is the seal pushed in too far? (was the case on a landy diff i looked at recently) measure the distances and see where the seal will contact.

sure it's not brakes?

oh, and when you pull the old seal out, check carefully the wear pattern.. perhaps the seals have not been installed square?

also check the new seal on the axle itself, see if it has enough resistance on the surface it rubs on. (as well as seeing if the sealing surface is in good nick)

[RobertoX]

It might seal against the collar, I honestly can't remember...
I'll check all of those things though, good points.

and its definately not the brakes as I've replaced the cylinders and it smells like diff oil and its coming out of the small hole on the end of the housing that is designed to divert oil leaks away from the brakes.

[nos4ag]

Definately sounds like a little bit of scoring from where the old one has been taken out. My diff did this aswell, as there was one tiny scratch. I dint leak overnight, but it did end up leaking!! Peeved me off puuling it too bit bits and rebuilding it agian.
Yeah, the silicone job sounds like the go to me too.

[RobertoX]

For anyone's future reference, although the toyota seals are about 5 times the price of an equivalent CBC or other distributor's seal they are worth the extra pennies!

Even with cleaning up the seal seat of any scores and using some sealant the cbc ones didn't work (tried about 4 all up) wheras the toyota ones worked without any sealant whatsoever!

Also, a length of 62mm od PVC plumbing pipe is an awesome tool for getting the seal to go in straight, wst style

[bathurst-91]

yeah man, jus wack a little bead of high temp red, or blue rtv (any quality sealant) around the edge of the seal that leads in so it fills any imperfections in the housing

ive used stock seals that were bent previously, and it leaked. I then applied said sealant with old seals and it 100% sorts the problem. it holds up for drift!!! so its all good for anything else.

so yeh, sealant FTW

[BrianRA23]

As well as having some oxygen sensor safe silicon I also use the Loctite 515.

The 515 does not need a cap on when sitting on the shelf as it only sets when squashed, which means it is always ready to go. When the excess gets squeezed out it disolves in the oil so will never block a oil gallery or similar On the outside the engine i does set so can be cleaned off at any time.

My brother is a diesel mechnic and when working on a mine site had a larger digger come in with an oil leak out the side. He apparently squeezed it in the hole with the engine stil running and it fixed the problem. I prefer to fix things right, but it sold me on using the product

If there is a machined finish (with or without a gasket) or I am fitting a seal I will use 515, pressed steel sumps I use silicon (oxy sensor safe).

When reinserting the axle after changing the seal you need to take care so that it doesn't get scored. If you support the shaft while inserting it there should be no problem.