Hey y'all, I know that this subject has been beat like a dead horse, but I am having transmission overheating issues that I haven't seen covered yet. Please bear with me, this might get a little long. about 3 months ago, I was coming up a grade towards home, when the trans temp gauge on the dash started screaming at me. I couldn't get it to cool down, so I had it towed home. After reading Mark Kovalsky's take on the subject, I determined that the bypass was stuck open. I replaced the internals in the bypass with the Sonnax kit, and my problem was solved, or so I thought. Last month, same thing. This time though, I found a huge amount of metal in the oil, and the cooler in the radiator was plugged. The trans had 160k, so I figured that I had gotten all of the life out of it. So, I figured while I was installing a reman trans, I would do all of the upgrades that I have been putting off for years. I replaced the radiator, installed a 6.0l cooler, a Derale inline filter, new Ford bypass and added an Autometer trans temp gauge. Upon driving, the temp went to around 220 degrees. I checked the flow, and I am getting about 11/2 quarts in 15 seconds, but no matter what I eliminate the trans still bypasses, unless I eliminate everything. I even tried the Sonnax kit in the Ford bypass, to no avail. Also, the dash gauge doesn't go to a warning stage. I'm lost. Any ideas would be appreciated.

 

Something is restricting the flow in the cooler circuit. You could have a damaged line, a delaminated rubber section, a bad cooler, or an inline filter that has too much restriction.

 

Thanks Mark for the reply. This thing is starting to drive me nuts. all of the rubber hose is new, along with the radiator and trans cooler. the only original parts left are the steel lines, which I thoroughly flushed. I rerouted the hoses to each cooler individually, and it would bypass with either one connected. The only way that I could get it to not bypass was to connect the outlet to the inlet. I have double and triple checked for kinks. Mark, can you tell me on the '02 factory gauge, what temp range will it read in normal ranges?

 

It will read normal from 50°F to 230°F.