T-case leaking out of front plug question

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Forum Lifer
Feb 8, 2004
Cloverdale B.C. Canada
my T-case is leaking out of the front plug. see pic .has anybody ever changed this ? is it a toyota part only . is it as simple as pull out the old and bang in the new. or am i missing something i am hoping to do this with it in the rig .
i am using an AA long adapter (sm465) i think i should be able to knock a new one in without pulling the case. I hope ..

any info would be greatly appreciated .

The plug is not the seal. The shaft seals via an o-ring. If your adapter does not cover it it is possible to drive shaft out to pop out plug and replace o-ring. use a follower and be careful and you might get lucky. the follower keeps the thrust washers on the idler cluster from getting outa shape or place.
John, if it is a pre-80 case, there is only ONE seal, and it is on the rear of the shaft, just inboard of the keyway so in fact the plug is the seal for the front of the case.

Remove the key, tap the shaft forwards just enough to pop the plug out, knock it back enough to clean all the oil from the seat the plug sits in, use a good quality sealant on the lip, set a new plug in and peen it.

Plug is still available from Toyota. IIRC, about two bucks.


Mark A.
thanks for the info guys . my plug has a small crack in it . so i need to replace it . i'll give it a go .
i hope i can just knock it out .and put a new one in .

both ends of the shaft started weeping sometime after a rebuild so I cleaned the area well with brakeclean and smeared a finger full of RTV silicone. Problem gone for almost 10yrs. Only one side shown but you get the idea.

NICE! :grinpimp:

i have done that already ,but it still leaks, i cannot get the silicone to dry fast enough to stop the leak .
the oil always seems to find its way through :doh:

i have the plug on order 3 days from Cali to Canada . i'll see if i can get it in without to much dissasembly of my rig . how much gear oil will seep out of there once i get the plug out. will i need to drain the case again
i am not really wanting to drain it because it has 2 day old gear oil in it .i just finished replacing the rear output seal :doh:

oh well ,i'll get it all sealed up and leak free.

drain the case into a clean container and reuse it. While it's empty clean and seal.

These trucks don't leak...they just mark their spot.
I decided to pull the case this morning .is this what the plug looks like ? (see pic)
i have not picked up the new one yet . i decided to replace all the seals and check everything .

all looks good ,even the idler gear shaft is nice, t-case is clean :doh:

i think it may have been leaking between my AA adapter and my t-case.
(front t-case input seal)
or it may have been leaking out of the back of the tranny through the gasket
and the adapter housing . there are no seals between the adapter and the back of the tranny (sm465)

question . what would cause a seal to wear out when all there was is a spud shaft with a bearing on each end sandwiching the input gear and the pto gear
i don't see the shaft moving around much to damage the seal as it is just floating in the t-case only . it isn't part of the tranny. or do seals just wear out .
the seal may be 10-15 years oldit has been in there for awhile , just curious

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heres a few more pics .one of the spud shaft showing input gear .smooth sealing surface
and the rear of the tranny ,gunk in the adapter housing what keeps the oil in there just the gasket between the adapter and the t-case?

the bearing you can see on the spud shaft also is a sealed bearing ,helps to keep the oil in the tranny or t-case from migrating either way

tranny is also still full of gear oil and nothing leaked out the back ,amazing that that rear bearing isn't floating in some gear oil , i guess it splashes around in there quite well.
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