trans flush or not to trans flush thats the question
 

Just picked up a 2003 h2 33k miles 1 owner hummer. I don't know what the trans has had done to it for the 33k miles so i am looking for some opinions. Trans works fine, i will be installing a aftermarket trans cooler this weekend and bypassing the rad cooler to eliminate the potential pepto problem. I will be using this h2 as my trip and tow vehicle. I have heard of horror stories about flushing and would like to know everyone's opinion. Should i just do a pan drop and filter, or pan drop filter and torque converter drain or the whole flushing of the system. What fluid do you recommend?
Thanks
Greg

I took mine to grease monkey and they did a great job! In addition to the tranny I had ALL the fluids done (minus differentials and engine oil which I did). I take all my vehicles there to have the same done.

I would drop the pan and replace the filter with a quality AC Delco filter and refill with some Synthetic ATF. I like Amsoil ATF but there are lots of good brands. I also like to add a bottle of Lube Gard transmission fluid supplement. It's really good and endorsed by most car manufactures.

Hey Greg - searching the forum for trans flush recommendations. Did you ever come to any definitive conclusions on this? Ive heard/read very firm thoughts both ways .... just filter and drain .... and complete flush and new filter.

Took to local shop ... guy said tranny fluid dirty and he’d recommend flush at “dealer” since the H2 evidently requires a special adapter. Local GM dealer says they can’t do it ....

Anyway ... wondering ....

Thx

I have a 2010 H3 Alpha. I alternate every 30K between drop and drain and a flush.

When I bought mine a long time ago it had 32k on the odo. One of the first few things I did was replace all the fluids, diffs, tranny, transfer case, oil, brake fluid, etc. Basically everything because I had no idea what had been done or not done and I wanted a fresh start. I did not drop the tranny pan to replace the filter though, just did an oil swap.

I would drop the pan and replace the filter. That way you can get a look at the bottom of the pan and the magnet to check for excessive metal or clutch material. I replaced the stock cooler with two good coolers and bypassed the radiator. Now it's rare that it even gets to operating temp. The radiator cooler is more of a heat exchanger that also helps bring the trans fluid to operating temps. This is good if you live in cold climates. I live in SoCal so there's not so much need to warm the fluid.