Proud owner of a '78 FJ40 but discovered an oil leak on the transfer case... how to fix? (1 Viewer)

[Ollie88]

Hi guys,

I'm the proud owner of a '78 FJ40 since last Friday, immediately made a 200km trip with some offroad which all went fine this weekend but at the first refueling stop I found out that the transfer case was leaking. After a minute immediately a few drops, so I guess leaking much more while driving with hot gearbox oil.

I made some pictures of the transfer case which clearly shows it's dripping oil from what it looks like a hole that was filled up with silicon kit? Does anyone know what belongs here? Looks like there might have been a plug in there but maybe someone lost it and filled it up with silicon kit?

Also, too avoid too little gearbox oil which may screw up the entire gearbox, how/where do I fill it up and with what type of oil (+how do I check how much is still in there?)
Would appreciate the help and looking forward being part of this forum!

Cheers
Ollie

 

[brian]

lol there will be more

 

[Ollie88]

Do you know what used to be at the point which they filled up with silicon kit? And does anyone have photos of where the drain plugs are for both the transmission as well as the transfer case and both fill points/plugs?

 

[GA Architect]

Do you know what used to be at the point which they filled up with silicon kit? And does anyone have photos of where the drain plugs are for both the transmission as well as the transfer case and both fill points/plugs?

TOYOTA LAND CRUISER 40 55FJ40LV-KCJK - POWERTRAIN-CHASSIS - TRANSFER CASE EXTENSION HOUSING | Japan Parts EU

TOYOTA LAND CRUISER 40 55FJ40LV-KCJK , TRANSFER CASE EXTENSION HOUSING

www.japan-parts.eu

 

[Ollie88]

Hmm is it the 36111C plug? It doesn't look entirely the same as mine to be honest... could it be that the fill plug is missing and they filled that with silicon?

 

[GA Architect]

The fill plug is the lower left item in the pic above.

 

[Ollie88]

Thanks GA Architect, so it's the one in the middle (right from the fill plug) that's leaking. I just checked and seems the bolt is still there, what's the purpose of this bolt/plug? I wonder how it can be leaking if standing still while it's actually placed higher than the fill plug? Obviously when driving with hot oil it's different story.
Has anyone had the same issue I have, if so what was the fix?

 

[brian]

To keep the idler shaft from walking out of the case.

 

[pb4ugo]

It looks like the idler shaft is leaking. The tcase probably needs a rebuild. In the meantime be sure to keep it filled with oil. When you checked the tranny level was is overfilled?

 

[sogncab]

I wonder how it can be leaking if standing still while it's actually placed higher than the fill plug?

Lubricant gets thrown everywhere in the case by the rotating assemblies. That's how the bearings and gears are lubricated and cooled. Almost every thing is above the oil level, and not submerged.

 

[SteveH]

80w-90 gear oil (or 75w-90) is what both the transmission and transfer case require, as far as lubricant.

 

[bhsdriller]

drop the whole thing and do a re-build/seal i'm sure it needs it

 

[pjohnson]

There's an o-ring behind all that silicone junk. The only way to replace it is to pull the t-case. That is why is was goobered with silicone in an attempt to stop the leak.

As mentioned, your t-case very likely needs to be reconditioned and resealed.

 

[sogncab]

i'm sure it needs it

I'd do the axles too, just for peace of mind. I'm sure they need some love as well.

 

[Ollie88]

Thanks guys, yes it turns out it's leaking from the top of transfer case as well. I took the old silicone off and put some Loctite flexible sealant on it which seemed to have worked but now the top is leaking as you can see here.

Does anyone know how I can check whether it's not overfilled? Is that the bolt on the left on the picture?

 

[65swb45]

Unfortunately, the particular point at which you are seeing oil is a known weakness in the case itself. IOW, You could have a crack.