A tough one....

[Racer-X]

Originally Posted by H2 Rocks

Hope your wife gets well soon, Racer.

Why would your truck do this twice? What causes this to happen?

Well I don't know what causes it but there is a wall in the radiator that separates the coolant from the tranny fluid. They are both cooled in the same unit (when stock). That wall can rupture and apparently does more so with the H2.

I've had it happen twice now and I've seen it a couple times here. As Phil says GM has 1800 reported cases.

I talked to the dealer again after they got my truck. They are looking into plugging off the radiator section of the tranny cooler and running a separate one so this can't happen again. They did say it CAN be done.

As a side note - I watch my gauges when I wheel. Nothing ever got overly hot and the rig gave me no warning until it started acting up.

[H2 Ranger]

The internal cooler of the radiator serves a dual purpose. It heats up the transmission oil for cold areas such as Alaska and it also keeps the oil from overheating as well. Often the Engine runs hotter than a desirable transmission temp. So routing the transmission cooler thru the radiator in the current setup makes the trans temp go up more than desirable in a arid enviroment. I believe that you will get more life from a Cooler Transmission say about 175 degrees, and the transmission oil will not break down so fast. While I am not an expert on thermo dynamics, I still think a lot of transmissions are destroyed from improper operating temps. While in your case I would think it was a poorly mfrg radiator, but it has given you the opprotunity to try a remote cooler. If you decide to get it done that way make sure you get enough surface area for the cooling and have an end result of what you are looking for. Also hope you wife condition has improved.