Hot Plate

[scoutpappa]

I live in houston and it's getting to be real summer here (high 90's and 100% humidity). I took a drive today of about 30 miles one way and when I touched the transmission cover plate (auto 727 recent fluid and filter change and band adjustment) it was hot. Like electric motor casing hot (hold hand on it for five seconds). I was running 65 for most of the trip and there is no insulation or heat shield between the transmission and the plate. So the question is, does that seem like it's too hot or is it normal for these temps? I am going to insulate and try to provide a heat barrier of some type because it is affecting the ability of the new vintage air a/c to cool off the cab. That thing is like having the stove on in a pop up camper. Anyway if anyone has dealt with this because it is normal, please let me know what you did to mitigate the heat.

 

[Robert Kenney]

As a rule of thumb 140*f is a 5 second hold your hand on threshhold temp. So not to bad.

Check the fluid color. If it still looks ok I'd drive it so long as it still shifts ok.

Craig (ihon member) made a great post regarding your problem and his solution..

http://www.forums.IHPartsAmerica.com/basic-tech-questions/1245-dynamat-sound-heat-insulation.html

 

[scoutpappa]

I haven't put an ir temp gauge on it but the swepco fluid is bright red and smells fine (not burnt). The transmission shifts fine (I set second for a slightly longer hold to keep up with houston traffic, this thing is a dd). Thanks for the links, as I was just wondering if anyone else had noticed this (and it seems they have). All my other scouts are standards and I never really noticed that kind of heat radiating from the cover plate. Seems like I have some more work to do

 

[Michael Mayben]

Typical oem 727 transmission operation means that the internal fluid runs at 180>200*f. Roughly the same temperature as engine oil once everything is warmed up to normal temp.

A properly installed auxiliary tranny cooler simply means the tranny oil temp is maintained at the normal temp when heavily-increased loads are applied over time. We do not want tranny oil temp to be below a nominal 175*f in operation.

The standard radiator-mounted transmission heat exchanger works just fine in normal street operation if the entire engine cooling system is properly serviced. Adding an external heat exchanger to the transmission is done for when these vehicles are used for extended periods of use in trailer pulling, off-road operation, and extreme service such as pushing snow, etc.