What can be said about the 4-speed New Process NV833 overdrive manual transmission?

[hatzie]

Originally Posted by Gregski

Thank you, but what do you mean "don't use gear oil in it" than what should I use and why?

The aluminum case A833 from the 80's used Dexron III... Gear oil is too heavy. The rumor is they changed something and you'll burn out the countershaft needles. Best case the heavy oil makes it shift strangely and use more fuel.
You can't use Dexron VI in them according to GM.
The GM 88861800 fluid is cheaper than the Mobil ATF "Dexron III compatible" fluid that lists compatibility with GM 88861800 on the back label.

Bulletin 04-07-30-037E: Release of DEXRON-VI Automatic Transmission Fluid
"Any vehicle that previously required DEXRON®-III for a manual transmission or transfer case should now use P/N 88861800. This fluid is labeled Manual Transmission and Transfer Case Fluid."

You can't use Dexron VI in most power steering applications where you could get away with Dexron III either... OTOH There's a TSB for my Impala and several other mid size GM cars from the aughts that says to replace the power steering fluid with Dexron VI... Roll with the changes and try to keep up.