Howdy all: Can anyone point me in the right direction for information on the design of the 3 speed W/Overdrive available in some Chevy cars and trucks. I was given a complete 64 Chev 1/2 ton with 3 on tree, and the Overdrive pullout shift on it. I'm trying to figure out how well that O/D gear was made in that year "when good metal was still cheap". In other words would it take a power shift at high R's and lots of torque W/3000 pounds of weight against it ?? Could be a dumb question, but I love to experiment . Thanks all Wil
That is a Saginaw transmission. GM used them early on before the stronger Muncie & Borg Warner T10 came along. GM last used the Saginaw 4 speeds behind low HP econoboxes like the Vega and Monza in the mid to late 70's. IMCA dirt track racers like to modify the 3 speeds into 2 speeds. You can even take a Saginaw 4 speed and modify it slightly to use the overdrive unit. Hot Rod magazine did an article showing how back in the mid-70's. It might last awhile as long as you stayed away from drag slicks and sticky drag radials. If you have 500HP and some traction you would be better off using a different transmission.
Borg Warner built the overdrive units, they were used on several different 3 speed trannys. If yours is a 64 you need to see if it is a Saginaw or the early muncie 3 speed. The Muncie does not have a syncro first gear and is pretty weak. The Saginaw would be a great setup behind a 350 engine. I tried to run those Saginaw overdrives in my 455 Skylark in high school. I broke several trannys, but I NEVER broke a single piece in the overdrive unit. The overdrive unit is pretty strong, much stronger than the trans section. I built a hybrid 4 speed with the overdrive and I also ran the 3 speed setups. The 3 speed actually works better, you set it up to split the gears with the overdrive and you have a good 6 speed. Thanks Brent
Thanks for the input, I'm thinkin after hearing all this, I'm gonna let that 64 sit complete, fire it up once in awhile and put her on the auction block, after pulling up internal diagram on that thing, it would be next to impossible to have any kind of a quick shift that would work as well as many other trannys. Thanks alot Wil
