can anyone tell me bout early buick three speeds with overdrive would like to find one for my 1940 buick coupe if any were available, the rear end is a 411 n trans is low ratio also top out at 55 at 3300rpm help!!!!!!
I never say never, but in my 60 years of messing with cars, I never saw a Buick 3 speed with overdrive! Dave
Your best bet is going to be changing the rear axle ratio, I think. Like Dirty old man, I've never heard of or seen one with O/D, but stranger things have happened
I don't remember ever seeing an overdrive in any GM car with an enclosed drive line. The information I have lists the axle ratio as 4.41 to 1, and few mechanical options were available on any car built in 1940. If you plan to cruise the Interstate at 70, more modern drive line bits may be in your future.
Check out the Buick Club of America web site. It may be possible to put a later ring and pinion with better highway gears in your original rear end. Good luck!
You can use the third member from anything through '55 models and I belive the lowest numerical available is 3.36. It seems to me there was a thread here on the HAMB on this very subject in recent weeks with pictures and details. Ray
i dont know much about early buicks. but its still a gm car, maybe you can find a kit to adapt a borg t5 to it...it has a built in OD in 5th gear.
here is a guy that adapted a t5 tranny w/ an overdrive to a straight 8 buick engine...kinda vague info, but still useful. http://www.teambuick.com/forums/showthread.php?17032-T5-Install-on-the-50-263
The issue here is the torque tube driveline and coil spring rear suspension that makes swapping a transmission a much bigger deal than vehicles with an open driveline in the first place. Yes, a T5 or other suitable trans can be adapted to the straight 8, I am doing one now (an Aisin AX15 5 speed).......but that requires lots more work and fabrication. The OP apparently is looking for lower RPMs at highway cruise with minimal re-engineering of his car, hence the recommendations for a ring/pinion ratio change since no overdrive transmission exists that will merely bolt in. Ray
1940 thru 1955 ring and pinion gear from a dynaflow car has the gears we need to calm the rpm's down. Here is a link that I am going to follow this winter to make my 50 a better cruiser.. http://www.jalopyjournal.com/forum/showthread.php?t=319814 Also, http://www.jalopyjournal.com/forum/showthread.php?t=620854 Good luck, Chuck
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