Overdrive

[McDar]

Did GM ever offer the Borgwarner three speed overdrive transmission behind the flathead Cadillac/LaSalle engine? Thank you; Evan

[jim43]

Never did that as far as I know. Never even heard of it. Because the X frame is such a close fit it is impractical to attach an overdrive. Some serious frame modifying would need to be done, I am not saying it couldn't be done.

A friend did mount and overdrive back behind the X. That required two short driveshafts of course, and some careful mounting of the overdrive at an angle so none of the U joints were put to extremes.

He also put one in a Buick, same thing in the middle, but dealing with a torque tube on that one.

I have a 1936 Ford phaeton with a Borg-Warner mounted in the middle of the torque tube. Works great and really quiets the engine down at driving speeds. No more straining engine, but a bit more shifting.

This is going on a bit about Cadillac not having an overdrive, but there it is. Jim43

[Guest grumpydad]

Hi

I an in England

what i did was fit a 5 speed box

that was floor change

and made a 2 pice propshaft

the car is on 16 inch wheels

and at 65 mph is doing 2000 RPM

so a nice and easy crusing speed

it will also get 15 miles per gallon

[McDar]

Thanks Guys, never gave the X-frame a thought but of course it is a factor. I have one in my 37 Buick (custom built) and I agree that cruising 61mph at 2000rpm is a big improvement over the factory gearing. Will get the LaSalle ( 1940 52 series sedan) on the lift and mull over the possibilities. I'm a bit leary of the T5 offered in the S10/Mustang/Camaro as to it's durability in a heavy car.

[Guest grumpydad]

Hi

I used a LT 77 gearbox

this is a English gearbox

it is used in landrovers

and vans