quote:

Originally posted by gumybob:
I understand the "Heat Exchanger" theory, helps warm up the tranny fluid. In colder States, I would have kept my stock inline with the external, but in Phoenix, I was overheating for no reason going up hills and just sitting at lights. After I placed the external and bypassed the radiator, I haven't got above normal this summer.

Think about it, if you have the OEM cooling circuit after the external cooler, it's not like the transmission is going to get fluid that's too hot. The external cooler will take it down as far as it can, either below the coolant temp or not. If it's below the coolant temp, well, it can only get as warm as the coolant as it goes through the radiator, and unless your engine is running hot, it's not going to be something the tranny isn't expecting anyway. If the external cooler can't get the fluid down to coolant temp on its own, well, the pass through the radiator will only bring the temp down more.

In other words, there's no harm in doubling up, and it can help.

quote:

Originally posted by OffroadX:

quote:

Originally posted by gumybob:
I understand the "Heat Exchanger" theory, helps warm up the tranny fluid. In colder States, I would have kept my stock inline with the external, but in Phoenix, I was overheating for no reason going up hills and just sitting at lights. After I placed the external and bypassed the radiator, I haven't got above normal this summer.

Think about it, if you have the OEM cooling circuit after the external cooler, it's not like the transmission is going to get fluid that's too hot. The external cooler will take it down as far as it can, either below the coolant temp or not. If it's below the coolant temp, well, it can only get as warm as the coolant as it goes through the radiator, and unless your engine is running hot, it's not going to be something the tranny isn't expecting anyway. If the external cooler can't get the fluid down to coolant temp on its own, well, the pass through the radiator will only bring the temp down more.

In other words, there's no harm in doubling up, and it can help.

Look at it this way, prior to putting on an external, I would say my tranny fluid was around 250 degrees, going through the radiator it cooled it down to 230 but that's still overheating the radiator and causing the truck to run extremely hot. Now if I put on the external and still run it through the radiator, the external might cool it to 230, and then the radiator might take it down to 210, still causing the truck to run hot. Bypassing the radiator keeps the radiator running normal around 190 or so, not hot at all.

I wasn't worried about the tranny getting fluid too hot, I was worrying about overheating my radiator because it's not capable of cooling the engine and tranny going up hill in 112 degree weather. My question is whether the external cooler by itself is enough, someone suggested a small fan and that was a good idea.

But I do get your point. In a colder climate, I would definitely double up, I just don't want to overheat again trying to go up to the Rim this summer.

I wouldn't think that your stock heat exchanger would affect your coolant temp that much?

quote:

Originally posted by JS:
I thought I'd post this in the general since it may apply to other vehicles. I have a 2003 pathy and was pulling about a 3000lb boat. It was 100 degrees out and half way through my trip my transmission felt like it did not know what gear to go into and then like it started slipping. I pulled over and could smell something burning... I assumed this could be the transmission fluid. The motor didn't get hot at all!

I pulled the dipstick and the fluid was not red but maybe a little brownish tint. Did I make the correct assumption that my tranny over-heated (I have a transmission light, but it never came on)? Do you think this caused any damage? Would the best action be to get it flushed and add the largest cooler I can find?

Has anyone every had this problem? Thanks for the help.

I GOT TWO COOLERS one for the power steering
and the trans. i got them real cheep at the parts yard ! they came off two Chevy vans
CAUTION you have to put them on the low side
I found out that you can kill a cooler on the
Power steering