does anyone have a 3speed with overdrive?

[davidh]

Okay, I know it was an option and was supposed to be for light duty but does anyone have or still use a 3speed with the overdrive? was it just a cable pull or what? Just interested. I've looked inside many a 67-72's.undefined

[chief bobber]

I had one for a while, but it wasn't hooked in correctly. all it had was a electric switch on the shifter. I liked it until I blew it.............

[greenvilledave]

ttt i am looking for one too thanks dave

[Pilgrim]

Also looking for one. Thanks.

[northerngmc]

My uncle has a late 60's 1/2 ton that he purchased new and still has it in it.

From what I understand when they came from the factory they had a kickdown on the gas pedal and a govenor on the engine and an electric solenoid on the transmission that changed it into OD. No pull cable, just shift up through the gears and if you let off the gas it would shift into OD.

If you find one now, chances are it will not come with the govenor or the kickdown. Some guys hook them up with an electric toggle switch in the cab and shift in manually. You have to be cafeful and not lug it in OD.

Good reading on the subject can be found at

http://www.classictruckshop.com/club...over/drive.htm

Good luck finding one.

[pritch]

I was up at my friend's the other day and when he saw the 3 speed in my Panel he said he had 3 speed OD that would fit right in. Somewhere. We looked all around his place and couldn't find it, but he said he would look some more. He was real sure it hadn't gone to the dumps. He said he would give it to me if he found it. He thought it came out of a car-like a 64 something, he wasn't sure.

[pjmoreland]

I had a manual 3 speed with an overdrive on my 67 swb. It had a silver t-handle knob marked "OVERDRIVE" attached to the bottom of the dash. The t-handle was connected to a cable that actuated an arm on the overdrive unit. When the t-handle was pushed in, it would put the transmission into a freewheeling mode, kind of like a bicycle, where the engine could idle while coasting down the road at highway speed. There was also an electric switch that operated a solenoid in the overdrive unit. In order to shift into overdrive, you had to first push in the t-handle cable, and then rev the engine up, let off the gas, and as the engine rpm started to fall, actuate the solenoid. Once the engine rpm fell down to the correct level, the solenoid would engage the overdrive gear with a little clunk. If you turned the solenoid on too early, the fuse would blow before overdrive engaged. If you turned the solenoid on too late, then the correct rpm would be missed, and the fuse would burn out. If you forgot to shift out of overdrive, and came to a stop, all the gears would be geared up, and it would be difficult to get started in first gear. It was kind of a pain, but I could get 21 MPG on the highway.

[HOTFUN]

pjmoreland, it sounds like the one you had a problem. You can start out in or out of overdrive. I have 5 of these tranny's around here and my friend still has one in his 67 long box he has had since 1971 that got me started on these years ago. There are two types of overdrive tranny's used by GM in the 55's through 1969. The first style used in 55 to 64 cars and trucks was a non snychro first gear and was a Muncie and has a 4 bolt side cover. In 1965 they changed to a HD fully synchroed 7 bolt side cover saginaw and still with the Borg Warner OD. Overdrive was being replaced by the automatic and pretty much a dying breed by then and they built so very few of them till about 1969.
I have changed my 56 Bel Air with 265 over to a Saginaw style OD from a 68 Chevelle. It is an awesome unit being so very quiet and easy to shift. When you get to 3rd with the OD "T" handle pulled you just let off the gas pedal momentarily and it shifts to overdrive at about .79 ratio for a 20% reduction in engine speed if I remember right. It is nearly the same comparason to using a two speed unit on big trucks. you could in fact go through 6 speeds with this 3 speed overdrive but they don't recomend racing with the OD kicked in. As my 56 Chevy car is in paint stage now I have not driven this one for a while but my friend's 67 with this tranny on his 283 he regularly gets 18 mpg on the highway and about 13 when the overdrive was not hooked up. If anyone is seriously interested in either style I should have two complete setups of each type. PM me and I will try and answer any questions about them from my 10 years experience with them.
Mark

[HOTFUN]

PM's sent.

[Scrubby]

Like Mark, I am swapping my '56 wagon over to a 3 speed overdrive full synchro from a '67 el camino. They are almost impossible to find. I think I just got lucky. My wagon originally had the 3 speed overdrive without the synchronized first gear, and that drove me nuts. But the overdrive was way cool.

[Pilgrim]

Mark, sent pms.