47-59 B/W R10 Overdrive Operation Question

[SanJosesSteve]

I want to add an overdrive to my 270 motor with 3 speed transmission. I have the Official Guide B/W R10 overdrive book by Randy Rundle. It states that when the overdrive electrical components are functioning properly, it never free wheels below 28mph.

My question is, will pulling the handle under the dash immediately disable the system and restore direct engine braking, if so, can the handle be pulled at any time, under any operating condition? It’s not explicitly spelled out in the book.

While free wheeling under 28mph seems reasonable, I know of several twisty steep mountain roads here where 28mph would seem really fast and potentially boil your brake fluid before getting off the grade. -Steve

[mr48chev]

All I am going to say is that on my 51 Mercury coupe with BW overdrive in the 1960's it fully freewheeled when slowing down in overdrive.

The reason being is that I had what others said were the loudest pipes in town but when I didn't want cops to hear that rapppppp when slowing down in town I would leave it in overdrive and the engine would go to an idle and I would have to use the brake rather than the engine to slow down to a stop. That trick saved me many a ticket.

The overdrive gave the best of both worlds though. Fair acceleration with the lower geared rear end even with the flathead and decent gas mileage at 1963 highway speeds for a kid who could barely afford to put a couple of bucks worth of gas in at a time.