Trans temperature gauge

Mark, I yield to your expertise with no issue. I agree that the trans fluid will be the coolest if it goes through the vehicle radiator first and then through the trans cooler. This is great to control the upper temperature in hot weather. Apparently this is not the best overall solution in cold weather or modern transmissions would not come with bypass circuits to maintain a minimum trans fluid temperature. However, on older non-bypass transmission fluid circuits I would have to conclude that the maximum trans fluid temperatures were more of a concern to the manufacturers than minimum trans fluid temperatures.