Several years ago i had a neighbor(who does this for a living) rebuild a transfer case for me in an F-250.He stated that at work,they always use 40 synthetic oil instead of ATF after a rebuild.We used this in mine and i drove it for 3 years with no problems.I am considering doing this in my Ranger.Anyone else ever heard of or tried this?

 

Wirelessly posted

Use ATF

 

Use what ever is in the transmission. The weep hole in the extension housing allows fluid to seep into it and sit on the front inputs shaft. So when you go up hill it, fluid flows in. Then down hill it flows out. If the seal on the input shaft is not 100% you will mix the to fluids. Over time it may become an issue for on or the other.

 

On Rangers, I have heard of people running 30wt in the five speed manuals to make them more liveable; I have never heard of anyone swapping the ATF for 40wt in a transfer case.