With my 1989 Bonneville nearing 200,000 miles i was wondering if the transmission would benefit from a tranny cooler. I know it'* a little late mileage wise but anything i can do to save this tranny would help me out as i think i'm probably much harder on the transmission than the previous owner. Alway I was wondering does the TH 440 Transmission benefit from a shift kit. I'm not hard on the car but i would like to get as much longevity out of the car as i can before replacing things. Also living in Wyoming the mountains here are another factor when dealing with this transmission. Any thoughts would be much appreciated.

A tranny cooler is a good idea for any tranny, no matter what the mileage. It will help to extend the life of the tranny by keeping the fluid running a little cooler. Heat is one of your transmissions worst enemies. It'* what helps to cause it to breakdown before it'* time.

The price of a cooler is a small price to pay for a few extra years out of the tranny. I think you will find that most people here will agree. :P

I already had a stock cooler on my '93, but followed the same advice on the forum, and ADDED one right in front of it. I also changed my thermostat from a 195° to a 180°. Made a good 20° difference in average operating temp. Good, cheap fix for a little extra life!