ISO upgraded LML trans cooler

ChaseTimmick

New member
Jul 26, 2026
1
0
1
Arizona
2012 LML I had the trans rebuilt by copperhead diesel performance. However with the rebuild it has more line pressure causing more heat. I have 37s not towing and after a 15 min drive my trans temp is 190, I live in Arizona ambient temp is 115 pretty much all the time. It’s causing hard shifts into converter lock when it’s hot. Is there a good upgraded trans cooler available? I still have the stock cooler and I was told that it’s not in the “danger zone” so don’t worry about it but no one else I know has this issue I’ve seen the PPE bar and plate cooler does it work well? Should I add a switched 800 cfm cooling fan? Any advice would be appreciated!
 

Woody35

Member
Jan 4, 2013
93
43
18
I have a Mishimoto Trans Cooler. Highest Temp I've seen was 170F city driving with 100F ambient. I have a DPC Converter which supposedly runs a bit hotter compared to others.
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
3,936
836
113
Central OH
No your temps aren't high, but to me that's high for such a short drive. I'd suspect they didn't flush the cooler properly during overhaul