Weeping from transfer box

[Jpdv]

Hmmm. Not from either the fill or drain plug (they're both bone dry) but one of the lowest bolts of the set that go around the transfer box appears to have a very slow weep. It's not even dripping noticeably, but I've seen a 'dewdrop' of fluid welling on it the past couple of days... The logical first thought is a gasket leak at that point - does that make sense to people? Worst case is some sort of crack in the casting is flexing I guess, but there's nothing obvious...

Grateful for all helpful comments. I'd prefer to 'stop the rot' before a catastrophic failure if that's a likelihood.

[Eric SDV6SE]

Hmmm. Not from either the fill or drain plug (they're both bone dry) but one of the lowest bolts of the set that go around the transfer box appears to have a very slow weep. It's not even dripping noticeably, but I've seen a 'dewdrop' of fluid welling on it the past couple of days... The logical first thought is a gasket leak at that point - does that make sense to people? Worst case is some sort of crack in the casting is flexing I guess, but there's nothing obvious...

Grateful for all helpful comments. I'd prefer to 'stop the rot' before a catastrophic failure if that's a likelihood.

A cracked transfer casing would let all the fluid out in a rush. IMHO you have a gasket that is failing due to thermal cycling. With a small ratchet and suitable socket (torx?) Go around the casing and see if any are loose. 9/10 you can nip them up and seal the leak. Worst case, the transfer case has to come our and you will need to split and replace the gasket. Positive side is you will able to re-grease the drive shaft splines whilst you're there.

[scarry]

What Eric said^^^^^^^.

Then clean off and monitor.

[Jpdv]

To close the loop for anyone interested. The manual quotes 35NM torque setting for the bolts... I couldn't find one done up tight enough. I've nipped up all I can reach without removing the box, and will monitor the results.

[Jpdv]

And to confirm, that was the issue - now bone dry all round. A little disappointing that none of the bolts were at the recommended torque, but at least it was an easy fix...

[DiscoJeffster]

And to confirm, that was the issue - now bone dry all round. A little disappointing that none of the bolts were at the recommended torque, but at least it was an easy fix...

Well I might do mine then. Similar issue. I’d suggest they’d worked loose over time. Maybe stretch [emoji2369] wasn’t leaking from the start of its life presumably?

[Jpdv]

Presumably not, or I'd have been an unhappy camper buying a new one. I only noticed because I'd just done the fluid change and was checking that the fill/drain seals weren't leaking... Spotted the welling fluid on a bolt at the bottom. very slow, but definite, and definitely gone after tightening.

[Eric SDV6SE]

Well I might do mine then. Similar issue. I’d suggest they’d worked loose over time. Maybe stretch [emoji2369] wasn’t leaking from the start of its life presumably?

Probably would be worthwhile to undo and remove each bolt and add a dab of loctite to each bolt DJ.

[LGM]

Not exactly sure where your oil weep / leak is situated. I had a similar problem in that there was an oil weep that bugged me as I thought it to be an indication of a bigger problem in the making. From beneath the vehicle is impossible to understand where it was coming from. For other reasons I had the body off and there was the problem looking us in the face so to speak.
See the attached picture.
The thin black tube running along the top of the auto trans and into transfer case is fitted with an 'O' ring which had failed. This was the cause of the problem and had been 'weeping' for quite some time. A new 'O' ring was the cure, with some added silastic to be sure, to be sure!

[PerthDisco]

I take it that’s a breather?

[LGM]

I take it that’s a breather?
Certainly is!

[Scott_Lee]

Not exactly sure where your oil weep / leak is situated. I had a similar problem in that there was an oil weep that bugged me as I thought it to be an indication of a bigger problem in the making. From beneath the vehicle is impossible to understand where it was coming from. For other reasons I had the body off and there was the problem looking us in the face so to speak.
See the attached picture.
The thin black tube running along the top of the auto trans and into transfer case is fitted with an 'O' ring which had failed. This was the cause of the problem and had been 'weeping' for quite some time. A new 'O' ring was the cure, with some added silastic to be sure, to be sure!

Do you remember what size O-ring that was by any chance?

I have a similar issue and if I can replace the o-ring with the body on I'll change it to rule it out...

[LGM]

Do you remember what size O-ring that was by any chance?

I have a similar issue and if I can replace the o-ring with the body on I'll change it to rule it out...

Sadly I don't know what the O Ring size was. I will ask the mechanic tomorrow...Mon the 14th and see if he can advise.

[LGM]

Sadly I don't know what the O Ring size was. I will ask the mechanic tomorrow...Mon the 14th and see if he can advise.

As promised, I have spoken to my LR service agent who did the work, they cannot remember the size. On checking the LR parts system it does not show the 'O' ring or grommet as a separate item from either the breather tube or the transfer case.

Sorry about that!

[Scott_Lee]

As promised, I have spoken to my LR service agent who did the work, they cannot remember the size. On checking the LR parts system it does not show the 'O' ring or grommet as a separate item from either the breather tube or the transfer case.

Sorry about that!

All good, I plan on changing out the transfer case oil next week and while on the hoist I'll take the breather hose off and see if I can match the O ring. I do have a slow leak from the output Sharf seal, but it doesn't account for the number of drips I'm seeing every week. Hoping it's the breather and running down the back somehow to the transfer case bolts...

[eddy]

Hope it is not this leak Dumbest Oil Leak Ever Fixed on our Land Rover - YouTube (https://www.youtube.com/watch?v=pHYJsJb-tVQ) Check VIN!

[PerthDisco]

Deleted

[Briar]

Hmmm. Not from either the fill or drain plug (they're both bone dry) but one of the lowest bolts of the set that go around the transfer box appears to have a very slow weep. It's not even dripping noticeably, but I've seen a 'dewdrop' of fluid welling on it the past couple of days... The logical first thought is a gasket leak at that point - does that make sense to people? Worst case is some sort of crack in the casting is flexing I guess, but there's nothing obvious...

Grateful for all helpful comments. I'd prefer to 'stop the rot' before a catastrophic failure if that's a likelihood.

LR Time in Germany had this issue recently. It's a problem with the casting in the ZF Auto transmission, leaking into the join between the Auto box and transfer case. They did 2 videos about it. If it is you might want to check your Auto oil levels as you could start getting issues there with less oil in trannie.

First: Authorized LR Workshop Fail - Major Oil Leak - YouTube (https://www.youtube.com/watch?v=T4k9-_PzFN8&t=650s)

Second: Dumbest Oil Leak Ever Fixed on our Land Rover - YouTube (https://www.youtube.com/watch?v=pHYJsJb-tVQ)

Only affects certain vin numbers. Check out to see if this might be your issue. Worth a watch

[DiscoJeffster]

The above is only applicable to ZF 8 speed, so OP, what year and model of vehicle are we talking about?

[Gravy]

LR Time in Germany had this issue recently. It's a problem with the casting in the ZF Auto transmission, leaking into the join between the Auto box and transfer case. They did 2 videos about it. If it is you might want to check your Auto oil levels as you could start getting issues there with less oil in trannie.

First: Authorized LR Workshop Fail - Major Oil Leak - YouTube (https://www.youtube.com/watch?v=T4k9-_PzFN8&t=650s)

Second: Dumbest Oil Leak Ever Fixed on our Land Rover - YouTube (https://www.youtube.com/watch?v=pHYJsJb-tVQ)

Only affects certain vin numbers. Check out to see if this might be your issue. Worth a watch

Studied details contained in the second video, Discovery 4 vehicles possibly affected are 2015-2016, VIN 731301-812783.

My D4 falls within the VIN range at 738234, have not observed leakage to date, however the sump bolts have had to be retensioned after the sump was exchanged doing a fluid change.

Will monitor more closely.

[Jpdv]

Interesting, and thanks to Gravy for the spot. I am 8 speed, and do fall in that VIN range, so I may just have a more detailed look... No further issues to date though, and as I posted, all the transfer case bolts were below recommended torque before I checked and nipped them up. Occam's razor and all that...