Defender 110 Transfer Case Leak

Hi,

new user here with a potentially stupid question.

I've recently brought over my 110 to Europe from Australia where I lived for a while; I had a transfer case leak supposedly fixed before I left. The shop replaced all the seals and reassembled it.

On a recent long drive when moving from Germany to Spain, I again noticed a leak; I had a Land Rover garage in Barcelona again take care of it - unfortunately my Spanish isn't good enough to understand which of the seals they replaced (front, rear, bottom plate). I subsequently took it on another long trip, and guess what...leaking again.



Due to the move, I've been bouncing between apartments until I sort out a permanent home, and don't have any repair facilities, nor my tools with me yet. Once I have a "home", I'll scrub the sump and see where the leak is, then get to work on it. In the meantime, is this common to see after long highway trips? I've read that RP 85w140 seems to at least temporarily solve the issue for some people.

Any tips/advice highly appreciated!

In the meantime, meet Tinkerbell:

Looks a bit like it may be coming out between the oil pan and the main casting. In which case a new gasket may help - FRC7104. I smear mine with sealant on both sides just to make sure of an oil tight join.

It is easy to damage the input shaft seal when re-fitting the transfer box on account of it being a big heavy lump. Just because the oil collects around the bottom of the box doesn't mean it's leaking at the bottom. Also check that the oil isn't red ATF, which would mean it's from the main box.

Thanks both - I'm currently having a new centerpiece welded for the roo bars (the last owner decided it'd be a good idea to bolt a really nice Warn winch onto the front of the bumpers because there isn't enough space behind it) but as soon as it's done, I'll give it a thorough underbody wash and have a look where it's actually coming from.

Is this something I need to worry about when doing long distances? I somehow get the impression that so far it's only happened when I've driven ~100 in very warm weather. Do the seals have a tendency to somehow shift when they heat up?

I think that the hotter the oil gets the thinner it gets and the faster it leaks. In the short term just keep an eye on the levels and you won't go far wrong.

I was thinking it looked more like transfer box than main box as you can usually detect a reddish tinge in the ATF from the main box. The seals should be OK up to about 190 C, but in the course of a long drive the transmission and oil heat up and get thinner so it's better able to ooze out of the crevices.

Too slow!

Brown said:

I was thinking it looked more like transfer box than main box as you can usually detect a reddish tinge in the ATF from the main box. The seals should be OK up to about 190 C, but in the course of a long drive the transmission and oil heat up and get thinner so it's better able to ooze out of the crevices.

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I kinda suspected something of the sort - thanks for that. The leak now hasn't been bad (it got a bit worrisome after the first long, hot drive but still not really awful) but I'm keeping an eye on it. Do you think the tip with thicker oil is worth pursuing?

If the oil is coming out just above the top left bolt in the pic then it is likely the O ring on the transfer box intermediate shaft is leaking.
The transfer box has to be removed to renew this ring as the shaft has to come out in the forward direction.
However I have done it by sliding the transfer box back a couple of inches [Two extra long temporary bolts help ] and then pushing the shaft [ It is sticks out of the back of the box but can not be removed that way] forward just enough to change the O ring.

Use only the required gear oil.
In the mean time top up often.

It helps if you stick to the recommended oil for the transfer case. After all, it is just splash lubricated - the oil has to get around by being thrown about by the gears so you don't want it too thick!

Another possible place it could be leaking is between the transfer case itself and the forward facing nose cone that contains the central diff and diff lock mechanism. This generally doesn't have a gasket and is fixed on with sealant, so it can leak occasionally. The only way you'll know is by cleaning it up and looking to see where it comes out of next. With the effect of the wind blowing by, and warm metal surfaces it can spread a long way.

Is that a drop of oil I can see on the bottom of the handbrake backplate? Might be worth popping the prop and drum off to see if anything is coming out of the rear output shaft oil seal.

johnsalomon said:

I kinda suspected something of the sort - thanks for that. The leak now hasn't been bad (it got a bit worrisome after the first long, hot drive but still not really awful) but I'm keeping an eye on it. Do you think the tip with thicker oil is worth pursuing?

Click to expand...

it will just create more heat on long runs