i am going to do this mod..on my 2003 H2
with a Flex-a-lite 4120 Translife Transmission Oil Cooler Kit

after doing a search on the various forums on hummer... there is no information on the below stuffs...

was wondering... do i need
- to top up the transmission fluid after i mounted the new cooler... if i do not know what was brand/type of transmission fluid is it ok to use a general type or better off to drain and retop the fluid??
- to bring the H2 back to the dealer to reset the computer as i understand from some threads the mod will affect how the computer pumps the fluid thru..

thanks for your help

 

I just did mod myself with tru cool tranny cooler, yes I had to top of transmission fluid because I used the recommended cooler and its pretty large so fluid was down a bit, I added 1 quart and its still a little low, owners manual will tell you what type to use, I think it was dexIII , I haven't heard of reseting computer for this mod and I have had 0 problems, I used tru cool 47391

 

YOYMON is right on.

 

thanks guys...

any reason for using the tru cooler?.. i am not thinking of towing anything greater than 4000lbs

 

actually tru cool that I used is overkill, I just went with what I found reading through these forums, well its overkill here in pa anyhow I can see how it would work awesome in hotter climate and towing often, my guage now barely comes off of 100 degrees when its 85 outside, I saw pictures of the fit and I liked what I saw so I ordered and used it

 

i am in upstate NY... so high temps i am not so worried.. i am more worried of the low temps we get here...

 

I know ive been worried a little about the same thing and opinions vary for the most part everyone thinks tranny fluid will be warm enough after just a little driving regardless of temp outside, im still researching to see what I can find, also thinking of changing tranny fluid to synthetic just because it wont get as thick no matter how cold it is outside, all I really wanted to do was avoid the radiator failure I keep reading about where fluids mix and take tranny out, one mechanic told me if im sitting in truck letting it warm up before I drive it (which of course I do) put it in drive and sit there and it will warm tranny fluid faster than just idleing in park, if there is problems in winter ill have to put thermall bypass valve inline that tru-cool sells

 

I did this install a couple of weeks ago and the cooler makes a huge difference. Before the tru cool cooler temps were 175-185 on a 100 degree day not pulling a trailer. After mod pulling a 5k lb trailer in 100 degree heat temp never got hotter than 150 in drive, on freeway doing 70mph. I put in the dex VI when i added fluid.

 

good info... greg260... thanks... planning to do it next month...

 

i have my 06 in the shop getting some stuff done and told the shop to install an external tranny cooler. They called me today to say that my h2 already has an external tranny cooler installed. There saying it looks oem. Does anyone know if this was an option or something from the factory?