T-Bone......I am in no stretch of the imagination a master mechanic, but, I am well versed in thermodynamics. I imagine from your comments that your original equipment cooler is built into the motor's water radiator and is designed to keep the oil as cool as themotor water. To me, there is no excuse for injecting heat into a cool transmission just because the motor is running hot. I would suggest either installing a separate oil cooler completely disengaged from the original cooler or to mount it after the original equipment to pull more heat out.
I would also suggest a "plate type", similar to a minature motor water radiator, instead of a "fin cooler" which is just a long pipe with fins on it. The fin cooler is sometimes bent in a double back loop to reduce it's length (making it easier to install or to keep the inlet and outlet ports on the same side of the cooler.) The plate type serves you better if you seriously want to reduce the tranny oil temps. You never mentined why you are installing additional cooling, pulling heavy loads?, high speeds?, older truck?, what are your oil temps running - under load and normally?....do you even need additional cooling?.....Just food for thought.
Ok more info. Its a '01 Suburban 1/2 ton with the 5.3 liter engine. Nothing heavy duty, just a family wagon 4x4. I want it/need it to last a long long time. The only stock cooler is the radiator which cools both the engine coolant and the tranny fluid. I've never seen the thermostat move higher than 180 degrees.
We want to get a camp trailer 3-4k pounds and the manual and everyone else suggests getting a cooler.
Dealership wants $350.00, independant shop wants $140.00, NAPA parts want 70.00 for the kit and guarantees even an idiot like me can do it. NAPA says either before or after the radiator works OK. That seems hokey. I thought someone here may know a better answer.
My Ford is a Ranger. Not exactly a big rig manly truck, but its a good hunting vehicle.
Hey T-Bone.....NAPA's right....it will work both places.....but as mentioned above, after the radiator will cool better. Place an after market temp gauge in the line and you will be able to monitor the tranny oil temperature as well.....For the cost difference I would go with the shop installation....just be sure to go with the "plate" style.....Good Luck!
Try to flare the ends of your transmission lines ,helps keep the rubber hoses for your cooler from slipping off.
You won't be able to flare it as good as copper as the tubing is hard but you will get a little amount.
If you put it to the cooler first this sends cooler fluid to the radiator cooler which helps engine run a little cooler, but you can go either way.
Quail Hunter......the comment about sending cooler fluid to the radiator cooler to help the engine run cooler only works if you remove the thermostat from the cooling loop. I don't think you want to do that on a '01 Suburban.
What I meant was if your pulling a good grade, maybe pulling a trailer, or if the tranny is working hard, the temps from the tranny will be very hot, if sent to the radiator it can actually raise your engine temp,
If the thermostat is already open on the climb then the temp can climb above the thermostat rating, so by cooling it with the aftermarket cooler before it hits the radiator should shutdown this scenario.