LT77 Gearbox question

[Defender200Tdi]

After some months of progress on my previously rather incontinent Defender, I have just one (yes, just one)oil leak remaining (yay) style_emoticons/<#EMO_DIR#>/biggrin.gif . It's origin has been difficult to pin down other than to say it's from the gearbox somewhere. The only reason I'm sure it's the gearbox is that when I originally bought the vehicle that particular leak was clearly ATF, so that ruled out the transfer box although it is from the bottom of the transfer box that most of the oil drips. I don't use ATF in the gearbox anymore but the synthetic gear oil I do use doesn't smell like the ordinary 80w90 I use in the transfer box, so I'm still sure it's the gearbox that is the source of the leak.

I think I've narrowed it down to two possible points. Either from the join between the gearbox and the transfer box (there's a seal in there somewhere isn't there?), or from higher up and running down so that it looks like it's from that join (or maybe from both places) :roll: . Upon closer inspection (taking the tunnel off) there's a fair bit of oil around where the selector remote housing bolts to the top of the box, so I'd like to renew the gasket there first if it can be don in situ (and hope that it's the only source of the leak(s)).

Now for the question...can I remove the four bolts that hold the remote housing on and remove it to replace the gasket, without first removing the gearbox selector housing and the transfer box selector housing? In other words, take the whole lot off together. Or do I need to disassemble both selector housings before I can remove the remote housing from the top of the 5th gear extension?

Also can anyone help with part numbers for the 4 top gaskets on the selector housings?

This is the last in a long list of outward leaks and if I can finally get that one plugged I can turn my attention to the various inward leaks.


Paul style_emoticons/<#EMO_DIR#>/biggrin.gif

P.S. I've also posted this question on the LRE forum without much of an answer so far, so my apologies if you've read it before. style_emoticons/<#EMO_DIR#>/biggrin.gif

[4bd1]

Paul.

I hope is is the selector housing.


If not
There are two seals between the gearbox and Tcase.
One on the output of the gearbox and one on the input of the Tcase.

Mine drips from there.
Bad news is the gearbox and Tcase have to come out to replace either.
Landrover now allegedly have new improved seals, which I tried, without joy.

It's a bastard of a job and I figure two attempts is enough for me unless someone can come up with a failsafe solution.

[Defender200Tdi]

Hi 4bd1

Unfortunately I have the feeling that the seal on the gearbox output shaft might be the main culprit. Is it not possible to change either or both of those seals just by taking the transfer box out and leaving the gearbox in place?

Also, is there a gasket between the transfer box and gearbox as well, or just the 2 seals?


Paul style_emoticons/<#EMO_DIR#>/biggrin.gif

[defute]

Hey Paul,

you are correct in thinking that either the gearbox output shaft seal and/or transfer case input shaft seal can be replaced by only removing the t/case from the rear of the gearbox. The gearbox does not need to be removed from the vehicle.

AND, no, there is no gasket or additional sealing device (other than the above mentioned seals) fitted between the gearbox and t/case.

It is quite common that the replacement t/case input shaft seal is damaged when refitting the t/case onto the gearbox. This occurs when the new seal is 'cut' as it is slid over the gearbox output shaft when relocating the t/case on it's locating dowels!!

Be careful!!

[Defender200Tdi]

The answer to my question is yes, you can remove the Remote Selector Housing from the gearbox, without first removing the gearbox selector housing or the transfer box selector housing. It's a bit of a juggle, especially with everthing covered in a liberal coating of silastic, but it can be done. :wink:

I've also removed the transfer box, thinking that the small amount of oil around the selector housing couldn't be the only leak with the amount that was dripping onto the drive. Bad news is, both the gearbox output seal and the transfer box input seal weren't leaking :roll: , so I could've left that lot alone. :x The good news is, the idiots that did the gearbox rebuild before I bought the vehicle (and committed a number of sins for which I'm payng), did actually replace the mainshaft, so the splines are perfect. style_emoticons/<#EMO_DIR#>/biggrin.gif They didn't install a cross drilled input gear in the transfer box though :x , so mine's off to have four 10mm holes EDM machined into it. They also buggered up the seal collar :x and although it doesn't leak at the moment, I'm going to Speedi-sleeve it just to be sure.

So, fingers crossed, this time next weekend I might have an oil-tight Defender. :mrgreen: I hope I'm not counting chooks before they hatch. :oops:


Paul style_emoticons/<#EMO_DIR#>/biggrin.gif

[Pedro_The_Swift]

My cynical predisposition is worried they might have wanted a second bite at your cherry,, not to do the input gear is 8O .


Good Luck defender200TDI style_emoticons/<#EMO_DIR#>/biggrin.gif