2004R Trans Temps

[Ribbedroof]

I find that chart interesting from the standpoint that nearly all OE setups run the fluid through the radiator, which commonly run 195* thermostats, yet the chart indicates a 35-40% reduction in lifespan at 200*

 

[Pettrix]

The 195F engine temp is basically for emissions and winter time driving. It serves no real purpose to have the trans see temps of 200F+. Heat kills transmissions.

The factory never cared or took into consideration if the trans will last 100k miles.

 

[olds307 and 403]

The 195F engine temp is basically for emissions and winter time driving. It serves no real purpose to have the trans see temps of 200F+. Heat kills transmissions.

The factory never cared or took into consideration if the trans will last 100k miles.

It may be why transmissions started dying earlier. I have seen quite a few from the mid 70's and up GM cars with toasted transmissions, not with super high miles. All were 195 thermostat, no external cooler, no towing and just died to early. It has made me dislike the TH200, TH350 and even TH2004R. Maybe the heat and no fluid changes? I got 400,000+ Km out of a TH250C, needed only a day of 403 torque to finish it off. It had multiple services which no doubt helped throughout its life. I also heard removal of whale oil from trans fluid affected it around that time in a very negative way. Hard to disagree, heat kills. Amazing since most new motors run around 215 stats now and can still do extended oil changes. Probably helps that everything takes 6 to 10 liters.

 

[bracketchev1221]

The water on the cooler side of the radiator has already passed through the radiator fins. It is not 195 degrees anymore. Most times, the water is cool enough that the trans cooler is RE-HEATING the water before it enters the engine.

 

[Doug213xrj]

X2 Run a big auxiliary cooler .

Doug

 

[454GrandPrix]

Or just run a big auxiliary cooler and bypass the radiator one. I am doing exactly that.

Same here.

 

[565bbchevy]

My Monte has a big auxiliary cooler with a fan but the thing I added that made the biggest difference for cool trans temps was the now unavailable B & M Fluid Consistency System and with a 4,000+ stall in a street driven car it runs at 180* even stuck in Dream Cruise traffic.

https://www.amazon.com/dp/B000PKDTI0/?tag=gbody-20

 

[Pronto-]

Depends on the mods. High stall needs a big auxillary cooler. I'ld run the lines to the radiator then to an aux cooler and be done either way unless you drive the car in cold weather. In that case add a bypass that doesn't use the aux cooler until the temps are hot enough.