MN6 transmission lubricant change

[Dave]

I am considering changing the transmission fluid in my 2001 six speed. Does anyone know where I can find what the proper lubricant is (is Mobil One OK??).
Also, what is the proceedure?

Thank You,
Dave

[Tombone]

I use Redline

[mqqn]

Hi Dave -

There have been those who voice concern over using some of the synthetics in the MN6, the concern being that some lubricants can cause premature wear of the organic synchronizer friction materials.

I have read that Royal Purple is ok to use, and I would not be afraid to use redline either, just make sure it is for manual transmissions.

Myself, I will stick to the Dexron - III factory fill lube. It's cheap and I can change it as often as I fell necessary. 4.1 quarts are specificed as the fill quantity in the GM service manual.

To drain/refill:

There is a drain plug (with the word DRAIN cast in relief on the "passenger" side of the trans) just forward of the halfshaft, near the bottom. Remove it and allow the fluid to drain.

Replace the drain plug.

On the other side of the trans is a plug with the word FILL cast in relief on the trans case just above it - remove that plug.

Pump 4.1 quarts of Dexron - III into the trans (I use a small fluid pump I bought at AutoZone just for this purpose for about $10).

Replace the fill plug.

Put two ice cubes in a small glass, fill with 1.5 oz of Jack Daniels.

Toast to your success.

best regards -

mqqn

[Dave]

Thanks mqqn for the info! It seems to be something even I can do!

Dave

[The Drakester]

- I use Royal Purple - Diff also!

[sigshooter]

how often should this be done?

thanks,

tom

[Vettefog]

I just changed my mn6 fluid out a few days ago with Redline D4 ATF which is synthetic but Dexron III compatible. My new to me '98 only had 20K miles with a pamperd life and the original factory fill trans fluid. I really didn't think it needed changing but I did it anyway because of the age. While draining it, I was surprised that the old fluid was a bit darkend coming out like it was slightly oxidized. These transmissions must be harder on the fluid than I realized. But what really surprised me is how much better the transmission feels with the Redline D4. Shifting gears is smoother and takes less effort than before. I'm curious if just changing to new Dexron III would have also improved the shift feel or is it from the Redline? I can only imagine it is a viscosity thing that make the difference in shift feel but perhaps there is more science to it than I realize.

Oh BTW, draining hot transmission fluid can be a messy ordeal. It is thin like water and can splash out of the drain bucket so beware.

-Ed