Torqueflite A604

Important Instructions

The A604 is the first transmission to control the release of one gear and the apply of another without the use of bands or sprags. It programs its shifting operation by sampling the vehicle's operation pattern while it is being driven. The sophisticated electronics present some unique installation problems that must be addressed if the transmission is to work properly and last.

To prevent 2-3 and 4-3 bindup and/or damage it is VERY IMPORTANT to 'fast re-schedule' the controller before road testing the vehicle. Because the controller will retain the program from the old transmission that had worn or burnt clutches it will increase the clutch apply rate. Most controllers won't re-set fast enough to prevent damage to the new clutches. To prevent damage the controller needs a 'fast re-schedule' before the road test.

With the wheels off the ground and the selector in OD position 1) Apply the throttle slowly until a speed of 45 to 50 mph is indicated. 2) Lift the throttle gently and allow the indicated speed to slow to 20 mph. 3) Gently apply the brakes to bring the wheels to a stop.

Repeat this at least 75 times while noticing the feel of the 2-3 shift. When a light throttle 2-3 shift no longer binds up or bogs the engine the transmission is ready to road test.

Take the vehicle on the road. At 38 mph lift the throttle and apply a very small amount of brake. If the 4-3 coast downshift is rough at 20 to 26 mph take the vehicle back up to 38 mph and lift the throttle again. At 32 to 35 mph add just enough throttle to barely make a 3-2 kick down shift. Do this 40 times and re-check for a rough 4-3 coast downshift. If the shift is still rough repeat the 3-2 kick down 40 to 80 times.

This procedure will program the transmission for proper shifts and should be performed whenever the transmission is repaired or replaced and whenever the battery is disconnected. Failure to follow these procedures may result in costly damage to internal components.

TRANSMISSION EXCHANGE CO is located at 1803 NE MLKing Blvd., Portland, OR 97212. Ph. 503-284-0768, 800-776-1191 Fax 503-280-1655 E-mail