[Chester Stone]

Richard mentioned checking for water in the transmission. Assuming there is no water found in the oil, transmission temperature should not be a problem. While I have a different engine and most likely a different model transmission, my experience may be informative. It seems to me that the only reason for keeping the engine RPMs high going down a steep grade is to maximize the effect of the jake brake. Since a diesel has no vacuum, down shifting going down hill has no braking effect, but the higher RPMs helps the jake do its job. The transmission will normally heat up going up a grade, and will heat up some more going down grade because of the jake. This last month while traveling from California on I-80 to Wisconsin, I went up and down several mountains that were up to 40 miles up and down. I use synthetic oil in my unit and the transmission temperature, while normally 200 degrees, went up to as high as 254 degrees on two of these long mountain stretches. As far as I can tell, there has been no damage to my transmission and it has operated normally during the remainder of my trip. Sorry for such a long post, but it seems to me that whatever caused the transmission to fail, heat or RPMs should not have caused it to crater. Allison has told me to not worry about heat as long as it has synthetic oil. Other may have a different experience.