Thread: Trannyman or someone...need advice

My engine modifications are listed here:

Engine

My problem: Starting the car my trans temp will be 74. After 20 minutes of normal driving my trans temp will easily get over 200+.

My question is: Why do you think my trans temp get so high?


TIA

Originally Posted by Trannyman95

This needs to be moved to the 4T65E section.

High transmission temps can stem to a lot of different things. For starters you have a pretty loose torque converter which is going to create more heat than a stock converter. BEFORE jumping to ANY conclusions....... Are you going off of an aftermarket trans temp gauge that is installed in the pressure port hold on top of the trans case? If so then those numbers are meaningless as the case heat soaks from the exhaust crossover pipe and these numbers are false. I see a lot of cars that read anywhere from 20 to 50 deg F too hot by installing the temp sender here. The best way to read the trans fluid is either with a scan tool OR by installing the sender for your gauge in the lower pan or in a cooler line. I dont know anything about the size and gvw rating on the Desert Fox coolers, are you using it alone or in conjunction with the engine radiator? Poor cooler flow will greatly effect the cooling efficiency of a transmission. This can either be from a valve body problem, partially restricted radiator or external cooler, and even sloppy bushings inside the transmission. What does it do going down the highway? It should run cooler on a long drive down the highway as lockup will be turned on and eliminates torque converter slippage which will lower the trans temp UNLESS the converter is slipping a lot and that will certainly create a lot of extra heat. Im pretty sure their converters use Kevlar lockup clutch material which is not designed to slip so the pcm must have the lockup min duty% table numbers increased to help out with this. Also if you are not using lockup in 3rd at all as the factory settings are set up you will be creating more heat as you have the extra slippage from the higher stall and no lockup as most in town driving will be with those conditions.

Going down the highway still produces high temps. I had this problem ever since I did the conversion at ZZP. Within 2,000 miles the first year I had to have the clutches and gears replaced and they switched the TC from 3500 to currently whats on the car 3250. Installed the trans cooler with no significant results.
I'm using the reading off the Aeroforce gauge...though I also have an aftermarket as well and like you say reads higher b/c of the exhaust heat. It's got to be something with programing in the PCM.......I hope.