How do I keep my 4r100 from getting hot?

 

How hot is it getting? You can put a larger transmission cooler from the 6.0 series trucks in it, that will help a bit.

 

How hot? What are you using it for. Installing a 6.0 trans cooler is an upgrade many 7.3 owners do. Are you changing the fluid at the proper intervals?



WH beat me to it!!

 

I have the original stock gage in the truck so I really don't know what temp it's getting to

 

The last time my tranns went out it started getting hot then eventually blew the seals out.
i had it rebuilt & the first time i pulled a trailer it got hot on me. Changed the bypass hose on the side of the trans & it worked for a while.

 

I might have 15,000 miles on the last fluid change

 

Early signs of a tc starting to slip, tc is always the first to go. Check to see if its not sliping. Also the by pass valve? Might be stuck clised and letting the tranny fluid reaching the transcooler

 

The tranny does get hot, I forget how hot but it is a specific number of degrees more than the outside temperature. You will need a trans temp gauge to start with. Or you could use an infra red temp reader and check it when it is hot.

 

Easy method to know if its getting hot is to spray some water on the trans oil pan if it sizzles or evaporate quick you know that thing is over 200° a little unorthodox but works.

 

Get a bluetooth adapter and a droid phone. Torque pro app and you have tranny temp. The gauge on the dash is not accurate until it is too hot.

 

what temp range should a 4r100 usual be running at?

 

I believe it's about 80 - 90 degrees above the ambient air temp. At least that is where mine likes to hang out.

 

Quick questions: Does this truck have a tuner on it?? Is this truck jacked up / lifted with huge tires & stock axle gear ratios??? These things can easily overheat a transmission STUPID fast!!


The next largest amount of heat generated in a transmission is from the shear fluid force that occurs inside of the torque converter. I would dis-connect both transmission cooler lines to inspect the cooling circuit for a blockage in the lines or in the radiator mounted cooler, or in the aux. cooler. , then run rubber hoses to a 5-gallon bucket & start the truck. Do you get good fluid flow from those lines? If so, re-connect the line that fluid was coming out of. Then re-inspect the return cooler line for proper flow. Doing this procedure, shows you what the cooler pressure line should be & what the pressure looks like as it comes back from both outside mounted coolers. Keep the fluid topped off during this testing. Keep in mind that doing this test will be cheaper than replacing the transmission, even just once! If there is not much flow, then there is a restriction in one of the coolers or the steel line itself. If the flow appears to be good, then replace the torque converter asap. I'd replace it, I'd replace that right away, first.

 

Per Mark K. design temperature is ~180*. Anything over 220* for a sustained time is entering no man's land. If you run too cool it will not dissipate moisture in the fluid.