Engine/Transmission (1998.5 - 2002) Transmission Heater?/ Cooler

[slomodiesel]

Gents; I am doing a makeover on my 98. 5 24v and with the transmission out and the exhaust off I noticed the transmission heater/cooler on the side of the block. After research- I think that in warm conditions a person while towing might benefit from bypassing the unit. In my service manual it says that overdrive will not work til 50 degrees and that is def not a problem in the summer within a min of startup. I think the heat calories added to the transmission line at the heater/ cooler should be bypassed during the heavy load time in summer. Anyone agree? Anyway- I am over-engineering a two guage system with before and aft temperature guages- and will test to see how much the cooler near the radiator lowers the coolant temp while towing 12,000 lbs and then how much the block side heater adds heat to the same fluid. Anyone else interested or has anyone tried anything like that?

 

[Spunkys Ram]

I'm curious to know what your results will be. It is a heater of sorts but also a cooler. Acts similar to a radiator, but for trans fulid. Please keep us updated.

 

[slomodiesel]

Yes- By looking at the unit it functions to probably stabilise the system as it would use raiator water to heat the trans up when cool or at start up and then to hopefully if the transmission temps go up it would help cool the trans fluid if the transmission is warmer than the radiator water. My first thought was that if I am a little more patient on initial start up and drive-off the transmission will be up to normal temp range soon- without the unit acting as a heater if the water temp is warmer than the trans temp. 2nd thought is if we are towing or maybe even running down the highway or interstate light that any heat we can eliminate from the transmission (through the block side unit) would be beneficial - also if the transmission was warmer than the water (probably in most cases while operating) if we bypass the unit we would not heat up the radiator water as much. I have a new transmission cooler in front of the radiator so all these temps are going to be interesting. Thanks for your reply Spunky -anyone else have any thoughts?

 

[Batphreak]

When I bought my truck previous owner had decided the coolant exchanger for the transmission was un-necessary. Dead wrong, even in winter (Missouri) the transmission was overheating and burning itself up. I believe that heat exchanger takes the initial heat off the transmission fluid so that the air cooler up front is more efficient. This is all with a stck truck and transmission, by the way.

 

[THoltz]

Gents; I am doing a makeover on my 98. 5 24v and with the transmission out and the exhaust off I noticed the transmission heater/cooler on the side of the block. After research- I think that in warm conditions a person while towing might benefit from bypassing the unit. In my service manual it says that overdrive will not work til 50 degrees and that is def not a problem in the summer within a min of startup. I think the heat calories added to the transmission line at the heater/ cooler should be bypassed during the heavy load time in summer. Anyone agree? Anyway- I am over-engineering a two guage system with before and aft temperature guages- and will test to see how much the cooler near the radiator lowers the coolant temp while towing 12,000 lbs and then how much the block side heater adds heat to the same fluid. Anyone else interested or has anyone tried anything like that?

Just curious what you found out using your two temp gauge setup?

 

[JohnBoy5]

i can totally see how this could cause the trans to overheat. i have measured temps coming right out of the trans well in the 250 degrees f range. so lets say you have 225 degree f trans fluid and 180 degree f coolant the exchange is going to cool the trans fluid down to 180 degrees f or some where close to that. thats a 45 degree f difference. just the nature of a heat exchanger is VERY efficient at what they do "exchange heat". that little exchanger is not going to be able to over heat the coolant. look how larger the cooling systems is compared to the volume of the exchanger.

 

[Dieseldemon]

It is not a heater it is a heat exchanger takes the brunt of the heat from the trans fluid before it goes to the air cooler in the front