My 6 speed has an all cast iron case. It is very stout and has a 1 1/4" diameter pilot shaft. What brand is it and what oil should I be using in it. Also what oil should be used in the transfer case.

 

It's a New Venture NV-5600. Takes a synchromesh fluid (5w-30). Popular brands are Pennzoil Synchromesh Fluid, Redline MTL and Amsoil MTF.

Transfer case takes ATF+4.

 

Thanks MikeyB. I read ATF+4 in the Owner's Manual for the transfer case, but only a Dodge part number for the gearbox.

 

I like the Redline Oil Manual Transmission Fluids because they are GL-4 rated. GL-5 is usually too slick for synchros. Check their website for weight recommendations, lean to the heavy side, since heavy use burns those 6 speeds up

 

Thanks for the tips. Although oil is certainly important on syncro life, driving habits and gear shifting skill is FAR more important. If there is no speed difference between shaft speeds, the syncros are not asked to do work.