Normal Trans Temp Gmt800

brandon_guzzo · May 18, 2010

I finally got my trans temperature gauge installed and driving today it was about 73 degrees out and my temp on the trans was reading between 188-192 going at about 55mph. Is this normal and what is a the "max" temp I can hit before worring about problems. I have a trans cooler on order but its not going to be in for three weeks and im going on a 150mile trip out of town with my 1900 pound trailer this long weekend. Thanks for the input

zedbear · May 19, 2010

I finally got my trans temperature gauge installed and driving today it was about 73 degrees out and my temp on the trans was reading between 188-192 going at about 55mph. Is this normal and what is a the "max" temp I can hit before worring about problems. I have a trans cooler on order but its not going to be in for three weeks and im going on a 150mile trip out of town with my 1900 pound trailer this long weekend. Thanks for the input

I bet that is about normal without an aux cooler. Mine runs about 150-175 with the factory aux cooler just driving around town in the 70 degree range. I hear if it starts to go well past 200 for an extended period, it can be a problem.

MD Chevy · May 19, 2010

I have a 2009 Crew Cab. I constantly see around 170 going 70 mph. The highest I have seen is 195 while ground hog hunting.

Nytemare · May 19, 2010

About the same temp as your engine coolant if you do not have the trans cooler...maybe a few (10) degrees lower if you have a stock cooler.

Max temp I would tell you to watch for would be around 210...You may want to slow down or pull over if it gets that hot...put the trans in neutral and keep the engine running to cycle the fluid through the cooler or the rad.

jro909 · May 19, 2010

question thats been rattling around for awhile, does the trans fluid cycle through the cooler in park? or only in gear or neutral?

96chevy7.4L · May 19, 2010

only in gear or neutral. In park the pump is not turning thus you can check the fluid level. Thats my understanding of it atleast.

dlstewart01 · May 19, 2010

only in gear or neutral. In park the pump is not turning thus you can check the fluid level. Thats my understanding of it atleast.

The pump is working in park. Do a line pressure check in park. There will be pressure. If the pump was not circulating fluid while in park all the fluid would be in the pan and you would get an over full reading on the dip-stick.

In this how to flush the trans, the fluid would not pump out idling in park if the pump did not work....

http://www.gmfullsize.com/forum/showthread.php?t=179148

jro909 · May 19, 2010

only in gear or neutral. In park the pump is not turning thus you can check the fluid level. Thats my understanding of it atleast.

The pump is working in park. Do a line pressure check in park. There will be pressure. If the pump was not circulating fluid while in park all the fluid would be in the pan and you would get an over full reading on the dip-stick.

In this how to flush the trans, the fluid would not pump out idling in park if the pump did not work....

http://www.gmfullsize.com/forum/showthread.php?t=179148

kind of what i thought, so park will cool the trans down then?

clemsonblozz · May 19, 2010

when you are "cooling down", you are allowing circulation without anymore load, so in theory it would cool down,,, but if you watch your trans temps while idling,, it seems like it'd take a very very long time.. I have the 11X11 stacked plate cooler,, and I run around 155 F on the interstate @ 70 mph and 85 ish degree's,, but in the 10 miles from the interstate to home,, it'll drop down to 140 F... But that's pushing a ton of air through the front end,, so at idle it might take a half an hour to get a good drop..

But, anything cooler than the temps you get with just the cooler in the radiator is a bonus...

Since my 11X11 install, I haven't passed 168 F pullin the boat,, but it hasn't been hotter than 92 F outside yet..

truckofwinandawesome · May 19, 2010

only in gear or neutral. In park the pump is not turning thus you can check the fluid level. Thats my understanding of it atleast.

The pump is working in park. Do a line pressure check in park. There will be pressure. If the pump was not circulating fluid while in park all the fluid would be in the pan and you would get an over full reading on the dip-stick.

In this how to flush the trans, the fluid would not pump out idling in park if the pump did not work....

http://www.gmfullsize.com/forum/showthread.php?t=179148

actually, if the pump is not working, the Transmission does not work PERIOD! and this is the reason why its not recommended to tow a 2WD Truck on the Drive Wheels, the Pump is driven by the Torque Converter, which is driven by the Engine. if the Engine is not running, neither is the Pump.

Nytemare · May 19, 2010

when you are "cooling down", you are allowing circulation without anymore load, so in theory it would cool down,,, but if you watch your trans temps while idling,, it seems like it'd take a very very long time.. I have the 11X11 stacked plate cooler,, and I run around 155 F on the interstate @ 70 mph and 85 ish degree's,, but in the 10 miles from the interstate to home,, it'll drop down to 140 F... But that's pushing a ton of air through the front end,, so at idle it might take a half an hour to get a good drop..

But, anything cooler than the temps you get with just the cooler in the radiator is a bonus...

Since my 11X11 install, I haven't passed 168 F pullin the boat,, but it hasn't been hotter than 92 F outside yet..

Very true...but if your pulling something and you get over 200*...its better to pull over and wait for the 30 min or an hour, than it is to try and climb that last hill to get on the flat and bring it up to 65 or 70MPH to get air over the cooler. That last hill could be the proverbial straw.

oldscsc · May 19, 2010

when you are "cooling down", you are allowing circulation without anymore load, so in theory it would cool down,,, but if you watch your trans temps while idling,, it seems like it'd take a very very long time.. I have the 11X11 stacked plate cooler,, and I run around 155 F on the interstate @ 70 mph and 85 ish degree's,, but in the 10 miles from the interstate to home,, it'll drop down to 140 F... But that's pushing a ton of air through the front end,, so at idle it might take a half an hour to get a good drop..

But, anything cooler than the temps you get with just the cooler in the radiator is a bonus...

Since my 11X11 install, I haven't passed 168 F pullin the boat,, but it hasn't been hotter than 92 F outside yet..

Very true...but if your pulling something and you get over 200*...its better to pull over and wait for the 30 min or an hour, than it is to try and climb that last hill to get on the flat and bring it up to 65 or 70MPH to get air over the cooler. That last hill could be the proverbial straw.

My trans runs a notch above 150F in mild weather.

zedbear · May 19, 2010

I had a 99 Dakota that did NOT flow fluid through the aux cooler I had installed when in park. It would feel hot right after driving it but after being in park for a minute or two, it would be cool to the touch......putting it in neutral would restore flow and it would get warm again. I know, totally different manufacturer but thought I'd throw that out there.....

brandon_guzzo · May 19, 2010

Thanks for the fast replies

Nytemare · May 19, 2010

I had a 99 Dakota that did NOT flow fluid through the aux cooler I had installed when in park. It would feel hot right after driving it but after being in park for a minute or two, it would be cool to the touch......putting it in neutral would restore flow and it would get warm again. I know, totally different manufacturer but thought I'd throw that out there.....

Good point....and I'm not sure either way...I know the trans shop put my truck in neutral to swap my fluid....but they used the flush machine with its own pump...so this could be apples to oranges.

I know guys have said they have done both park or neutral to use the trans own pump to swap out fluid.