Im looking for for a tranny cooler, what do you guys recommend?
Has anyone used these:

LPD coolers

They are supposedly self regulating to let cold ATF bypass the cooler.

Also, I would prefer a cooler with 1/2" hose fittings, to match the OEM hoses. It seems most coolers are smaller diameter.

 

b&m uses the same cooler get the one thats 11x11x1 1/2 " thick ...good coolers
I have a chevy 6.5 turbo diesel that would see very high trans temps 275 deg +when towing
and this last year on the way to mexico we topped he same grade on I8 and it never hit 200

 

Since the ATF is circulated through the heat exchanger (the big tank on the passenger side of the engine), I don't think the bypass for cold fluid is that important in this application.

I used a Flex-A-Lite fan mounted cooler under the bed, basically duplicating the optional "super duty" cooler that was available for the 1st Gen trucks. IIRC, the tube size is 5/8", and it has an adjustable thermostat to kick the fan on when it's needed. I'll have to dig up the receipt for the part number if you want specifics. There are some pics here:

Under bed trans cooler

 

Dan, i'd like to go with a setup like that with another filter. Only thing is when I was looking around they all had 3/8 inlets and our lines our 1/2. I didn't want to imped flow so I haven't made a choice yet.

What were the part numbers for that and what was the inlet/outlet size? I guess I could always weld up something to the inlet/outlet to keep the ID size up instead of screwing something into the fitting too.

I'm getting tired of the creeping trans temp sitting at lights and want this trans to last as long as possible.


Den

 

The one I installed last year is from Summit Racing, Perma-cool PRM-12318. It measures 10-1/2" X 21" long X 4" deep. With a 1250CFM fan. Let me tell you, it took a big hammer to fit it in under the bed. I installed it between the tranny outlet and the engine heat exchanger. When the tranny temps are around 240F, I can put my hand on the outlet from the cooler to the engine heat exchanger - that's how effective it is. Unfortunately while it solves the problem of the heating up during idling, it only slows down the temperature rise of the transmission when towing. Our TCs seem to be able to generate more heat than we can get rid of in standard form. The new cooler doesn't totally stop the rise. I think when we put a heavy load on the engine and transmission, regardless of how cool you make the fluid, the engine heat exchanger reheats the fluid back up to high temperatures again, and undoes some of the good that the cooler does.

This year I'm going to disconnect the engine heat exchanger to see what happens.

John

 

Den - The part number is 45951 (Flex-A-Lite). I'm pretty sure the tubes are 5/8" ID, but can't find the specs on their site anymore. The inlet/outlet are 1/2" NPT.

Flex-A-Lite 45951

 

John,
Nice cooler. That was one of the many I probably looked at, but the 3/8 inlet/outlet worried me. I wonder if that is slowing down the flow. I would put it after the heat exchanger though. Might help improve it's cooling.

Dan,
I bookmarked that one. Looks good. I guess you can here that turning on
Is there a remote control for the temp or is it set on the unit?

Den

 

Actually, it's hard to hear the fan while I'm driving. About the only time I hear it is when I'm stopped at a light with the window down.

The thermostat is part of the cooler, and has a **** on the side to adjust the "on" temp.

 

Doesn't the cooler go in the return line to the transmission so the temperature of the fluid is at it's lowest when it enters the ad-on cooler??

 

the b&m plate coolers come in 1/2 np also can be had in 3/8

 

The 3/8" you're talking of isn't 3/8" ID, I think it's 3/8" pipe thread. The cooler pipes look the same inside diameter as the cooler lines. No restriction. But you should check them out yourself to make sure.

John

 

Why wouldn't you just unhook the engine heat exchanger when you put an aftermarket cooler on? It seems like if anything the engine coolant would just preheat the tranny fluid and cause it to overheat faster.

 

In cold weather, the tranny can run too cold. Not sure what effect that has.

John