Transmission overheating

I know this your dealer has probably tried this, but, are you sure all of the transmission cooler lines have been run and checked. If there is one thing that your transmission does it is create lots of heat and that heat has to go somewhere. That is why your transmission has its own lines into and out of the radiator core.

One of those lines may be crimped up behind a piece of the undercarriage that your technician may not see. If that’s the case, then there’s no coolant circulating in the jacket around the tranny and the result is overheating and failure. It is also possible that the lines may not be caught and crimped but may just be collapsed inside an armored runner. If you look around the surface of your transmission it is more than likely that you will see several armored hoses. The reason for the armor is pretty evident. If you take your pickup to a worksite (supposing you are in the building trades) and your undercarriage hits, but doesn’t hang up on rock, the armoring protects the heating and cooling lines to the transmission’s waterjacket. Without armoring, the rock could just as easily have torn up the cooling line, which is the reason for the armoring.

The armoring is great but it does mean that if a line collapses, as was mentioned, you would never find it or even think to find it. Have your tech run all of the cooling lines into and out of the transmission jacket to make sure there are no collapsed lines inside the armoring.

Now, let’s suppose that your pickup has a secondary transmission cooler installed because you do lots of hauling (I think you mentioned you were trailering when the problem occurred). One of the recommendations that I would have given you when setting up your truck — I used to help people set up and buy trucks for a dealer — is to be sure that you have a separate tranny cooler installed. It’s like a special radiator dedicated to the transmission and helps keeps things cool so your transmission fluid doesn’t overheat and possibly boil away, leaving you high and dry.

Now, assuming you have the transmission cooler installed, has your technician checked all of the hoses going to and from the tranny cooler. Again, all it takes is one crimped or pinched line or a collapsed line to shut things down. If it is in an unnoticed area, then your technician may never notice it. Let me know what happens on this one, please. I want to see you get your pickup back soon.