Oil in manual trans/t case

[nate379]

I was just wondering on the oil in the trans and T Case. The book says 80w90 GL4 or higher.

Now is GL5 ok? The reason I ask is on other transmissions I've worked on GL5 is a no no because it eats the brass/bronze syncros.

Should I use gear oil or are you guys using other stuff? Castrol synchomesh/syntorq... Amsoil MTG, etc?

 

[JusMX141]

The transfer case is nothing but two gears and a few tapered roller bearings. GL5 is fine for the transfer case- I like it's oil to be as thick as possible to lessen the chance it would leak out the tail shaft seal.

The transmission is a different story. Some guys say all Synchromesh is fine; some guys say it doesn't lubricate enough. Some guys say 80W90 GL4 is the way to go, but it doesn't seem to work as well with quick-shifting as Synchromesh.

If you're willing to change your trans oil as often as your motor oil, straight Synchromesh is what I'd use. If you don't like to do maintenance, try mixing Synchromesh 50/50 with GL4 80W90. NO GL5 IN THE TRANS.

 

[mikelv]

Use Redline MT90 and call it a day.

 

[Spln_Hrd]

Use Redline MT90 and call it a day.

^^^^ +1

 

[nate379]

Hmm, don't think anyone around here sells Redline.

 

[Defiant]

Many threads on this topic are already on this site. Look in the FAQ.