1974 odd sound from transfer case (1 Viewer)

[inzel]

I am hearing a helicopter type sound from what I believe is my transfer case. It only seems to happen in 4th gear. 4wd works very well but possible there is some gear rubbing or something? I can hear it in 2wd only as I havent gone past 2 gear in 4wd. I heard I should only drive slowly in 4wd. My truck mostly sat over the last couple years so maybe it just needs to be driven more to see if it quiets down?

Any thoughts are greatly appreciated. Im fairly mechanically inclined but very new to FJs.

2F motor with a 4 spd trans

 

[3_puppies]

how are the oil levels in the trans and transfer?

 

[inzel]

how are the oil levels in the trans and transfer?

My mechanic says they are good but I will double check

 

[inzel]

Is there a guide I can reference to make sure I do this correctly? I assume its a standard manual tranny check?

 

[inzel]

I had to use a 17mm on the transmission and it seems normal. 19mm on the transfer case and it seems low. I will get some fluid and see if the issue persists. Thanks for the idea.

 

[inzel]

Will GL5 80w-90 gear oil work or does it need to be GL4?

 

[inzel]

That appears to have been the issue. Much quieter now

 

[3_puppies]

That appears to have been the issue. Much quieter now

is the transmision overfull?
when the seal fails between the transfer and transmission, the transfer case can lose it's oil into the transmission

 

[inzel]

is the transmision overfull?
when the seal fails between the transfer and transmission, the transfer case can lose it's oil into the transmission

I checked earlier today and it didnt seem too full. Looked to be right on the money actually. Oddly enough, I dont see any leaks so I will keep an eye on it for sure

 

[bikerider1001]

is the transmision overfull?
when the seal fails between the transfer and transmission, the transfer case can lose it's oil into the transmission

Is there a way to tell if the seal has failed, aside from the transmission oil pouring out when you remove the filler?

 

[hobbes]

Not as far as I know. It’s an internal leak, and one that is often missed.