The one on the side of the block. Is it really needed? When I pulled my tranny recently I couldn't get the lines un done from it so I cut them. I plan on just bypassing it with an aftermarket cooler, will this be a problem?

 

The nice thing about the heat exchanger is that the engine can help the trans come up to temp quicker and visa versa.

 

I know there a pain in the butt, but, i would by the new line and hook-R-back up. your tranny will thank u.
A tranny cooler on top or with that would be good if you tow a lot or heavy!

 

Uh...someone here, a few months back, bypassed theirs and noticed significantly higher transmission temps. To the point of not really working at all I think. So, yes, the heat exchanger IS needed. You would need a really large radiator to make up for it. Water (coolant) is capable of removing way more heat than just air.

 

I believe that might have been me. I had previously installed a third auxiliary cooler under the bed (sized super large with fan) which didn't work as well as I'd hoped, so I thought I'd cut out the engine heat exchanger hoping to make the transmission run cooler. Wrong. You'd be surprised by how much heat the engine heat exchanger takes out of the transmission. I assume because it is liquid to liquid. The transmission ran so hot without even towing anything, I put it right back in. Won't do that again!

John

 

Actually, I bipassed mine a couple years ago at the recommendation of my transmission builder. I did put a huge cooler, no fan supliment, up front. I don't tow, but have hauled heavy loads on the flat bed without any issues. I also plow about a mile and a half of private road with lots of lake effect snow. Burned up a new Jasper the first time. No issues since rebuilt (locally), bi-passed and better cooler.

 

How well it works may have a lot to do with which transmission you have in. Mine is the original, high slip transmission with no lockup. Plenty of heat.

John

 

its funny, I posted the same question over on Cumminsforum.com and got pretty much the exact opposite response, everyone there said its best to remove it and use an large aftermarket unit... go figure...

 

You'll have to replace the lines correct?


Take it out... bypass it. There is NO damage from taking it out. If you run into heat problems... you will know what it was.

Buy the new lines... hook it back up. You aren't out anything (you have to buy the new lines anyhow right?)


FWIW I have a DTT with an 89% converter and mine doesn't get hot. Truck sets on 35s with 354 gears.

 

actually I was just going to run rubber lines, I was going to bother with buying replacement hardlines...