Rebuilding The 904 Torqueflite Transmission - Mopar Muscle Magazine

Rebuilding The 904 Torqueflite Transmission - Three Speeds Forward
0404 MOPP 01 Z TRAN

When we took delivery of project Stealth Bomber, the '89 Diplomat police car, we set a goal that would require a fairly stout drivetrain. The first item on the agenda is the transmission. Even though the mileage was remarkably low, the 58,000 miles showing on the odometer were hard miles. The shift quality wasn't great, resulting in early and soft shifts. This, as well as lots of overlap, and a propensity for freewheeling in reverse until the car was good and ready to move, told us it was definitely time for a rebuild. Normally, we would lean towards the more bulletproof 727, especially in a drag application where repeated hard launches take their toll, but in this situation the A999 derivative of the venerable 904 was deemed more than adequate. Remember, our stated goal is a 150-mph capability, so we will maintain the ultra-high 2.94 rear gear, and upon launch the car will not be subjected to much shock. The '89 A999 our police car was equipped with is a wide-ratio transmission featuring a 2.54:1 first gear ratio, a 1.54:1 second gear, and a 1:1 high gear. An autopsy revealed burned high-gear/reverse clutches from overheating, burned bands, and a slightly-mangled, lower/reverse drum thrust-washer. We were fortunate that our 'Flite didn't require any "hard parts," as everything internal was serviceable.