Re: how do you engage the overdrive?

Posted by HH56 On 2021/4/18 14:18:22

You should have the R11 overdrive in your 51. Packard used the semi electric R6 overdrive in 39, the fully electric R9 from 40 to mid 48 and the much simpler in both mechanical and electrical operation R11 from mid 48 until the end.

Externally the easiest way to tell the difference between an R9 and R11 without climbing under the car is to look at the relay in the engine compartment. R9 relays are square black boxes almost the size of the voltage regulator and have 6 terminals while the R11 relay is a smaller usually a silver or natural metal colored rectangle with 4 terminals and a fuse on the side.

Under the car the R9 solenoid and lockout cable is on the right side while the R11 has them on the left side.

The aftermarket kickdown switch could be made to work for both units but wiring is different. The R9 would only use the two terminals nearest the plunger while the R11 needs all 4.