what a mess!! i drained just one qt, not 1.5 and no sign of leakege. book says 1.5 qt.
i finally ran a tubing from the fill hole across the cross member and held the tubing on a nipple on a qt bottle. i used almost 2 qt with all the messy leakage till it overflowed and pluggedi up.

can anyone verify the fill hole is about even with the cross member. i thought it was higher??

 

What year?

 

My 2006 requires removal of the speed sensor and add .25L thru that.(you can see the sticker instructions that they added). I haven't changed the fluid since I've owned it, but I'm planning to do it this week. Seems like there's lots of mixed feelings about what fluid to use.

EDIT= What fluid do you recommend?

 

Use whatever the Owner's Manual in your glove box says to use.

 

Figured you'd say as much. Manual calls for Dex3. Isn't in production anymore.

Some stealerships and autozone's database calls for Dex VI.

If you take a stroll through the other hummer forums, you'll find even more mixed opinions:

"Manual Transmission fluid p/n #888861800 is currently available through GMSPO. Current and past model vehicles listed above (Models 2007 Hummer H3 and prior) with either a Manual Transmission or Transfer Case that required Dexron III should use the Manual Transmission and Transfer case fluid #88861800. This fluid is a direct replacement for Dexron III used in manual transmissions and transfer cases. DO NOT use Dexron VI in place of the #88861800 fluid in any manual transmission or transfer cases as a failure may result"

I didn't ask what the manual calls for, I asked what he recommended. Royal purple, redline, manual trans fluid, dex6, etc.

 

oops,,,its a 2010 with 56000.
the fill hole just looked low, like midway down.

oh, my book says dex 6, its red. the old stuff was black,used.

 

Im using Royal Purple Synchromax manual transmission fluid #01512. It is a direct replacement for the GM #88861800 according to Royal Purples lubricant cross reference chart. http://www.royalpurpleconsumer.com/a..._Reference.pdf

Running beautifully after 9k miles.

 

Forgot to add - 2007 base model. GM part number taken directly from owners manual.