Gearbox Oil Drain

[Sailor96]

Hey fellas, last weekend I attempted to replace all of the fluids from top to bottom. Ran into issues with getting the gearbox and transfer case drain plugs out, as after a while it seemed to have seized a bit even with hitting it with penetrant and heating it with a heat gun, which worked for the rear differential. I checked to see if the factory service manual called out any tooling or sizes without luck.

Does anyone know the size of these gear oil drain plugs? I tried using the standard (imperial) wrench sizes form 1/4, 3/8, and 1/2 and none fit quite right. Do you guys use special tooling for this?

 

[astarozna]

There is a specific oil drain wrench....something like this.

 

[Fast Guy]

It's been a while since I last did this but it was a standard size. Can't remember if it was 3/8" or 1/2" though.

 

[Sailor96]

It's been a while since I last did this but it was a standard size. Can't remember if it was 3/8" or 1/2" though.

I found the transfer case drain was 1/2, which I also could not budge and was worried about rounding since most tools aren't square cut. The gearbox was something else for sure however

 

[Fast Guy]

Gearbox might have been 3/8th then.

 

[Cathode]

I found the transfer case drain was 1/2, which I also could not budge and was worried about rounding since most tools aren't square cut. The gearbox was something else for sure however
View attachment 4828View attachment 4829

I’m not saying it is the right thing to do but I’m sure I got mine (gearbox plug underneath) undone using the square stud on the half inch ratchet with no socket. It fits quite well. It’d be the same with a breaker bar.

 

[Sailor96]

She's well and stuck in there, with a 1/2 by 24" breaker bar I couldn't get this thing out. was at serious risk of stripping the drain plug. Might be time to torch it into submission with a blowtorch.
Gonna need a new plug most likely

 

[Cathode]

She's well and stuck in there, with a 1/2 by 24" breaker bar I couldn't get this thing out. was at serious risk of stripping the drain plug. Might be time to torch it into submission with a blowtorch.
Gonna need a new plug most likely

Annoying to say the least

 

[fubar andy]

Might be time to torch it into submission with a blowtorch.

Gas axe it!

 

[Sailor96]

I found some info based on an old thread. Apparently the drain plugs are 8mm and 13mm for the gearbox and transfer case.
https://www.gtiroc.com/threads/is-the-transfer-box-life-sealed.31868/page-2

 

[fubar andy]

I found some info based on an old thread. Apparently the drain plugs are 8mm and 13mm for the gearbox and transfer case.
https://www.gtiroc.com/threads/is-the-transfer-box-life-sealed.31868/page-2

Noted for when I drop mine out in a few months!