Landcruiser G/Box-T/Case Oil Leak Fix

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Landcruiser G/Box-T/Case Oil Leak Fix

Post by Homer » 17 Nov 2017, 10:28 am

G'Day Fella's,

I recently found an oil leak, in my BJ73 series Mid Wheel Base L/Cruiser (1990).
I did a bit of online research and found that when the internal oil seal, between the gear box and transfer case starts to leak, the oil tends to pass from the T/case to the G/box.
The first indication of this is that gear oil starts to overflow out of the gear lever extension, on the top of the gearbox.
Here is an image from another source, that's an example of this;
https://forum.ih8mud.com/threads/leakin ... lp.164584/

There are two options to repair this fault.
1) Pull the T/case off the G/box and replace the faulty oil seal.
or
2) Make and install an external oil transfer hose to allow the gear oil to drain back from the G/box back to the T/case.

Obviously, the former job (#1) is a major task but the latter (#2) achieves the same goal, and is a lot cheaper.

Here are some Before and After images that I hope explain the job itself.

My finger is pointing at the T/case Filler plug and the G/box Filler plug, is higher up on the left and side of the gear box.
DSCN2031.JPG
Left side of G/Box & T/Case, including leaking oil
DSCN2031.JPG (558.69 KiB) Viewed 8022 times


Here is the external braided hose and various fitting (another option, is to use Banjo Fittings on each end).
DSCN2030.JPG
DSCN2030.JPG (537.08 KiB) Viewed 8022 times


So I purchased two new filler plugs and washers, and then drilled and tapped them for 1/4" NPT (Note the Cork Plug, for temporary plugging, of the filler plug hole/s).
DSCN2034.JPG
DSCN2034.JPG (946.99 KiB) Viewed 8022 times


I then removed the original Filler plugs and replaced them with the new modified plugs.

Once both new modified plugs were in place, I then attached the braided hose to the top (G/box) plug and measured it for the correct length.
I then removed the hose and cut it (with an Angle Grinder with a 1mm thick cutting disc), to the correct length
I then cleaned out any abrasives and other ground up crap, from inside the newly cut braided hose (ask me How, if you want to know), and attached the end fittings to the hose.
I then attached the hose and fittings, to the new filler plugs.
Here is a couple of images of the hose and new filler plugs in place. Please note that I have already degreased all the leaked oil, off the G/box etc.
DSCN2035.JPG
DSCN2035.JPG (578.71 KiB) Viewed 8022 times

DSCN2037.JPG
DSCN2037.JPG (559.42 KiB) Viewed 8022 times


Please note that and luckily, the G/box Filler plug is physically higher on the vehicle, than the T/case Filler plug.
Also, what we are doing here, is installing a Drain and Transfer Hose.
This only works because gravity allows the oil to flow down hill, from the G/box Filler plug hole, back to the T/Case Filler plug hole.
So remember, the hose always has to have a down hill angle/fall to it!

I then took the Battle Cruiser for a run and got back under it and checked for any oil leaks.
All looks to be OK so Homer is a happy lad.

Hope that helps

Doh!
Homer
Last edited by Homer on 17 Nov 2017, 6:27 pm, edited 3 times in total.
Homer
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Re: Landcruiser G/Box-T/Case Oil Leak Fix

Post by bladeracer » 17 Nov 2017, 12:26 pm

Very nice fix :-)
I wouldn't have thought there'd be any pressure to require steel hose though?
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Re: Landcruiser G/Box-T/Case Oil Leak Fix

Post by Daddybang » 17 Nov 2017, 12:48 pm

Nice job :thumbsup:
No danger of the hose getting torn out by branches etc?. :drinks:
This hard living ain't as easy as it used to be!!!
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Re: Landcruiser G/Box-T/Case Oil Leak Fix

Post by Homer » 17 Nov 2017, 2:31 pm

G'Day Fella's,

Thanks for you kind comments.

Bladeracer, the inner PTFE tube is the heat resistant type (Black) and the S/S braid, is for extra strength and assurance ("Do it once, do it properly").

Daddybang, there is a transmission etc bash plate, from just behind the T/case forward 700mm (you can see part of it in the first image).
So it should be OK.......?

Doh!
Homer
Last edited by Homer on 18 Nov 2017, 5:58 am, edited 1 time in total.
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Re: Landcruiser G/Box-T/Case Oil Leak Fix

Post by Daddybang » 17 Nov 2017, 4:32 pm

:thumbsup: :thumbsup: :drinks:
This hard living ain't as easy as it used to be!!!
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