Sorry for taking so long to reply. The supercharger didn't add any heat issues at first, but as my rig aged and my campers got larger it started to become a problem. the Magnusson has a heat exchanger that keeps intake temps down but the biggest problem I found was the stock radiator on this model was too small. I had a constant issue and was chasing the problem until I upgraded the radiator. I did dual electric fans, bigger trans pan, larger trans cooler but the large dualrow http://becool.com/product-search/pro...-Natural-62102 radiator fixed the problem.

The trans lines run through the radiator unless you have already rerouted them, so with hot coolant temps comes hot trans temps. My trans runs cooler now and my coolant doesn't ever go above 200 no matter what I'm doing. We do go camping in the mountains in the summer which can get over 100 so it does good now.

 

Thanks, that will be something I look into next. It seems like they have a few sizes to choose from. I'll have to look into it some more.

 

I had a tranny problem this past weekend trip on my '03 H2 in the scorching heat of Las Vegas. We got there Friday night on a smooth drive. The very next day around 4:00 pm on a 110 degree afternoon, me and the family were driving on the uphill on ramp and noticed that the H2 was having a problem taking the on ramp and felt like it was on neutral. I kept on stepping on the gas but still wont't budge. Luckily, I was able to pull to the shoulder. I turned the engine off for a few minutes then started it back on, put it back in Drive and would move only a few feet and won't move again. I tried several times and the same outcome. I got it towed to a local GM/Cadillac dealer and the service advisor tried the same thing but came up with the same outcome. He said, he didn't feel any slippage but will let his tranny guy check it on Monday which was yesterday. The dealer called me back here in Cali and told me the bad news. They found metal debris on the tranny and caused the clogging on the filter. The tranny had to be replaced and also told me that they are also suggesting to replace the radiator. Total cost for both: $4500. 3 years 100k warranty to any GM/Cadillac dealer anywhere in the U.S. I know the saying: whatever happens in Vegas, stays in Vegas but this is B.S.!

Btw, I have 131k on my truck but only had it for 3 years and only racked in less than 1k miles which includes this Vegas trip

 

So did they find any coolant fluid in the tranny or are they just saying replace the radiator as a precaution?

 

I think as a precaution. The service advisor didn't mention anything about any coolant but his tranny guy just recommended to replace the radiator.

 

I don't think I'd waste my time/money on it. But rather do the truCool larger tranny cooler and bypass the radiator. It's a common mod. It's what I did and the tranny has never been over 180 towing up hill in 110 degree heat.

 

Will the dealership install it if I tell them about the tranny cooler? How much do they usually cost?

 

Have them do it or tow it to a local transmission shop seems like your only options. I would change the radiator and even though you are paying top dollar for the trans at least you will have a good GM warranty to back it up.

Sounds like the dealer is competent.

 

Yes. I had the GM dealer do it. I'm driving back there to Vegas on Friday night to pick up the hummer on Saturday. You are right calif phil, although I'll be paying top dollar for both radiator and tranny at least I'll have peace of mind for 3 years or 100k miles!

 

Well guys, after forking out $4500, I finally got the H2 back from the dealership yesterday. It shifted smooth and since they also replaced the radiator, the temp gauge didn't even hit the mid mark in almost an hour of traffic under the 110 degree heat with the a/c on the whole time back to LA. Great job by GM! I don't have to worry for 3 years/100k miles