Transmission running hot 230° when loaded

[aldo_45030]

Notice trans running hot last time i towed the fiver. ran apprx 230° after 3 hours of towing in 30° weather outside. I am wondering how to test and were to find the trans cooler bypass valve. I am wondering if it is sticking, the trans did not belch out any fluid. I plan on flushing and upgrading the cooler if there are any suggestions i am listening. The trans did not seem to be slipping and is already on its 2nd rebuild @ 86K showing.

 

[BJS]

pull the output line off of the transmission cooler and measure the flow delivered spec is minimum of 1/2 quart in 30 seconds

Tru-cool 4590 is a rather popular option that does well as does the 6.0L cooler from the later model super duty trucks.

 

[Tail_Gunner]

7.3's came from the factory with an undersized tranny cooler. This cooler for some reason, was even smaller than that on the V-8 or V-10 that had the same tranny. Prior to the advent of the 6.0, a popular upgrade was to remove the smaller 7.3 tranny cooler and install a larger gas engine one. When the 6.0 came out, the tranny cooler was enlarged even more. Then 7.3 folks began installing 6.0 tranny coolers for improved tranny cooling.

I installed a larger tranny cooler prior to the 6.0 coming out. I installed a gas engine tranny cooler and installed an auxillary cooler at the same time. The combination of the two has kept tranny temps in check quite well.