So I know one of the biggest things that destroys a tranny is heat. But what are some other factors that contribute to dreaded transmission death?

 

Almost anything that is not normal driving

 

You want the #1 reason? Lack of maintenance.

 

Contaminated fluid.

Valve body relies on close tolerances, clutch pack seals are critical and dirt will destroy them. Oil is cheap! I change my fluid and filter every 25,000 K.

 

Running 35's with 3.55 gears towing your 30 foot travel trailer.

 

stupid check valve

 

towing in overdrive. od unit doesn't cool properly and overheats.

 

Not adjusting your bands

 

Having the chrysler emblem stamped into the housing.

 

Driving around town in overdrive with a transmission not designed with enough oil flow to lubricate properly. One of the first things you do after ripping your screwed 518 tranny to pieces is drill another oil hole in the main shaft to ensure proper oiling. Thank-you Transgo Jr shift kit for this important modification information.