[A/S] Re: Transmission

["nickcrowhurst" <NickandSandra@xxxxxxxxxxx>]

Terry, http://www.turbodieselregister.com/ is an awesome source of 
information for us Cummins users. You will need to register, and then 
go to "search forums", select "24 valve engine and transmission 
1998.5 to 2002", and search on "synthetic automatic transmission". 
You should get 42 threads to read. (The answer to the universe, and 
everything...) I don't use synthetic, but the key point is the 
temperature of the fluid in your transmission when hauling the 
trailer. If you don't already have one, I suggest a transmission 
temperature gauge with the sender in the line from the tranny to the 
cooler, not in the pan. ATF oxidises rapidly with temperature 
increase, and the usual rule of thumb is to keep the temperature 
below 200 degres, and preferably about 175. You will see the highest 
temps when backing the trailer into a campsite, climbing a grade in 
second (when the torque converter will not lock), or stop-go in city 
traffic. If you find you have a problem keeping down to these 
temperatures, a double-deep aluminium tranny pan will give extra 
capacity on some models, and synthetic fluid is claimed to reduce 
temperature. I would stick with the recommendation in your owner's 
handbook, and I expect the towing recommendation is for changing the 
fluid more frequently when towing. I prefer to change a cheaper fluid 
every 10k miles, cleaning out the oxidation etc, than use a very 
expensive fluid I'm reluctant to throw away. Just my personal 
preference. It's heat that kills trannies. I'm no expert, just 
passing on what I've learned from reading. Good luck. Nick