Hello,

I have a 2500hd 6.0 4x4 with heads, cam, long tubes, intake, etc that I daily drive. I've noticed my trans temps running maybe 20-30 degrees below my coolant temps when I'm just running around town empty. Which makes sense I suppose given that the tranny fluid is routed through the radiator. For reference I'm using the stock trans temp gauge. I know this helps the trans warm up and (maybe?) dissipate heat through the coolant/radiator, but I don't know.

Haven't towed anything with my setup yet, but I will soon. Maybe with these HD trucks it's nothing to worry about, but I want to keep my trans as cool/happy as it can be.

I'm wondering if it makes sense to bypass the radiator and use an auxiliary trans cooler. I had a 2010 Nissan Titan where I did just that, but that was also because I installed a larger aftermarket radiator, mainly because those vehicles were notorious for radiator failures that would take the trans with them due to coolant in the trans fluid. I also installed a deeper aluminum trans pan with fins. The setup seemed to keep the trans pretty happy.

Wondering if anyone has any trouble cooling their trans on the HD gas trucks.

 

You could add an external cooler, with a thermostat to bypass it when it's not needed, downstream of the one in the radiator. Probably a better idea than eliminating the stock one altogether.

 

Get yourself a tru cool 40k and bypass the radiator.
My trans temp sits at 150° all day in 96° weather.

 

This decision is based on climate location imo, if you live somewhere where the high temp of the day can stay below freezing and not much city driving, leave it going thru the radiator. Someone who lives way south that might never see below 32 for more than a day or two doesnt need it thru both.
this is just based off of me watching my trans temps thru the years with a decent cooler and still routed thru the radiator. Driving the same truck in 95* weather and 18* weather requires some give and take for a happy medium imo.
regular heavy towing should seek the coolest temps possible tho no matter where you are..

 

at the very least upgrade to the 40k trans cooler and as stated above if you live in a warm climate you can bypass the radiator.

 

I run both rad cooler and aux cooler and I camp around 150-160 on a 4L60e. I live in the southwest, it was 99 today. I've towed thru the Mojave with this set up, and up and thru flagstaff with it too; and I've breached 200 a few times but only loaded

Come to think of it, this is probably only 40-50 degrees below coolant temperature, so not much delta to what you're seeing. I'm pretty happy with my combo for now. It's done me well, imo

 

Keep it running through the rad. Running through the rad helps the trans come up to operating temperature quickly. If the trans gets hot, heat can be absorbed into the coolant, otherwise the coolant keeps the trans at operating temperature. I added a 16k BTU trans cooler after the rad and even with the higher stall convertor the trans has been fine.

 

thats about the same as mine, and with you in the sw id say that is a pretty good setup.