I haul a Lance camper and generally see transmission temps in the 160 degree range. I’ve seen it as high as about 180 – 190 degrees or so. I do have a modified transmission, but the temps were about the same as before. I bought the trans cooler return line for a 95 that has a provision for a sender in it from Mopar4Less.com. There are a number of threads already submitted that go into various details on this subject. Try a search. BTW, I wouldn’t wait for the transmission light to tell me the transmission is too hot. By that time, it has already been to hot for a while. The temperature differences between the temp sensors mounted in the cooler line and the factory temp sensor located in the transmission can be as high as 150 degrees. The transmission is getting too hot when the temp hits 280 degrees or so measured at the cooler line. Personally, I'd back off way before then. Hope this helps.