3 Speed Overdrive
 

I have a C20 292 3OTT with 4.57s in a HO52. I was thinking about putting in a Saganaw or Muncie 3 speed with Overdrive. Anyone with thoughts about this? Anyone have ether of these transmissions in their vehicle or on the floor of their garage? Thanks

Re: 3 Speed Overdrive
 

I have one out of a '55-'57 Chevy under my work bench. I was always going to put it in one of my Hot Rods but it never happened. Unfortunately I don't know a lot about them because I have never taken the time to read up on them.....

LockDoc

Re: 3 Speed Overdrive
 

Saganaw or Muncie? Does it have the solenoid on it? Thanks

Re: 3 Speed Overdrive
 

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I don't really know who made it. Yes it has the solenoid on it. I know there was only one manufacturer back then. I don't want to sell mine. I edited your post above. You can't post a "Want To Buy" unless you are a "Premium" member. If you see one on one of the classified forums on here you can buy it, you just can't post a WTB. I don't know if there are any differences between the older ones and later ones but I'm betting there is..... I think they are pretty hard to find.

LockDoc

Re: 3 Speed Overdrive
 

Thanks for the advice. I'm gonna join. This is a great source of information.

Re: 3 Speed Overdrive
 

Good deal! Now you can go to the parts forum and post a "Want to Buy" to see what you can find.

Here are a couple of threads about them that might help too.

http://67-72chevytrucks.com/vboard/s...d.php?t=404773

http://67-72chevytrucks.com/vboard/s...d.php?t=350702


The year doesn't really matter I guess.

LockDoc

Re: 3 Speed Overdrive
 

Thanks Leon. I found those threads earlier. That's why I started to look into it. I just signed up for Premium membership and post a WTB. Thanks again, Jeff

Re: 3 Speed Overdrive
 

No problem Jeff. Welcome to the board.

LockDoc

Re: 3 Speed Overdrive
 

I know that Chevrolet put them in their cars. and truck from 1955 thru 1969. I had in a 55 chevy about 50 years ago. I think they are neat, but rare.

Re: 3 Speed Overdrive
 

Three speed overdrive was offered from Chevrolet 1955 through 1969. There are two types both manufactured by Saginaw. 55 through 64 use the lighter duty, non-synchro 1st gear Saginaw, '65 thru '69 use the stronger all synchro three speed that should be similar to the transmission in your truck now. The overdrive unit on the back of the transmission is manufactured by Borg Warner. The overdrive unit is essentially the same for all years. The later style is significantly better and a direct boltin but very uncommon . The early style is fairly easy to find but the shift linkage and placement is completely different and you would have to do some fab. to make it work. I had a good information source about these at home I'll see if I can get that to you later.

Steve weim55 Colorado

Re: 3 Speed Overdrive
 

Found this;

Re: 3 Speed Overdrive
 

I have one that came out of a 69 truck that I ran for over 100k miles till the syncros wore out and bearings got noisy. The truck was my only transportation so I put the original trans back.

I do know that the solenoids are different. The pick coil burned out on the 69.

I found an earlier one that was reported to come out of a 55 car. Former owner broke it apart for rebuild except for the OD tail which was complete. My plan was to use its solenoid. That's when I found out they wouldn't interchange. The shaft on the later models is longer.

I found a site where you could get rebuilt older solenoids and I called the guy but he couldn't come up with a new one - muttering something about gold hen's teeth.

With the help of a master mechanic friend - we opened up the can and unwound the pick coil, measured length, bought replacement varnished wire at a motor rewind shop, rewound it, and soldered up can. The points were in pretty good shape.

Re: 3 Speed Overdrive
 

Thanks everyone. I think it would be very cool to have one of these. There is one available on Ebay rebuilt without the solenoid and governor but it's expensive.

Re: 3 Speed Overdrive
 

For the price and a stronger transmission you should look into a NV833.
Lots of info here.

http://67-72chevytrucks.com/vboard/s...d.php?t=670789

Re: 3 Speed Overdrive
 

Thanks Geezer. More research...

Re: 3 Speed Overdrive
 

Everything you will ever need to know about the operation and service of the Overdrive Three Speed:

devestechnet.com From the home page click on Driveline Solutions and scroll down the right side of page. Several overdrive articles..........

Steve weim55 Colorado

Re: 3 Speed Overdrive
 

Thanks. Excellent source!!

Re: 3 Speed Overdrive
 

I'm putting one of these behind my 250 in the GMC. Have a standard 3 in there now, and want to keep the 3ott, but want overdrive so I can cruise down the freeway. Bought a Saginaw with the 7 bolt side cover and an R10 overdrive unit. The big mistake I made was buying one that was missing the governor. Can't find a replacement anywhere. I may end up wiring it with a switch if I can't find the right governor.

Re: 3 Speed Overdrive
 

That is what I've found that the solenoid and governor are very difficult to come by. Did you have to have your drive shaft shortened? Did the shift linkage have to be modified? Thanks, Jeff.

Re: 3 Speed Overdrive
 

Haven’t installed yet, but most likely I’ll need to change yoke, but don’t need to shorten drive shaft. I got different shift linkage because the current tranny is a 4 bolt side cover.

Re: 3 Speed Overdrive
 

So... The 4 bolt side cover is the same length as a 7 bolt? I have a line on a 4 bolt now but I have a 7 bolt straight 3 speed in the truck now. I take it the tail shaft spline for the 4 bolt is different than the 7 bolt. Also, what part of the linkage do you need to change? The listing says the 4 bolt I'm interested in came out of a 67 Belair. So I take it the 7 bolt comes out of a later model.
I found this on Ebay. If you read the description, it says to call this place for solenoids and governors. https://www.ebay.com/itm/SAGINAW-3-S...frcectupt=true
Here is the link to the thread on the 4 bolt http://67-72chevytrucks.com/vboard/s...45#post8386745

Re: 3 Speed Overdrive
 

One of the things people used to do was bypass the governor with a switch. The governor serves to drop overdrive out at a low speed.

Bypassing the governor gives you a hill hold. The transmission will not backup with the overdrive 'active'. Need to backup - turn off the switch.

Re: 3 Speed Overdrive
 

Yes, I measured to make sure. They are identical length. But yoke splines are most likely different. The seven bolt tranny uses the more standard spline of the 4 speeds. The linkage is just plain different between the 4 bolt and 7. Shift arms are different and linkage to column is different.

Re: 3 Speed Overdrive
 

Yes, I may end up doing this if I can't find the proper governor. I have the diagram for it. Lot of debate on that no back up thing. Early versions of this transmission were like that, but the newer versions (mid to late 60s) eliminated that lock pin set up. You COULD back up, you just toasted your OD unit in the process. Very expensive mistake.

Re: 3 Speed Overdrive
 

A couple things to keep in mind on the four bolt three speed: The design of this unit goes back into the 1930s. These units are not as smooth and quiet as the seven bolt currently in your truck. The four bolt shifts a little sloppier and clunkier by comparison. Also remember : first gear is not synchronized! The four bolt is not nearly as strong as the later 7 bolt. That said it will work just fine in a truck used for light hauling and cruising.

Yes, the four bolts uses a coarse spline slip yoke. Should be a common find, I'll bet Danchuk sells them new for tri five Chevys. I'm not sure about the length but I can put a tape measure on both transmissions when I get home in the next couple days.

It's possible to operate The overdrive wired straight to the solenoid with a switch inside the truck and nothing else. All you have to do is make sure the overdrive lock out lever is fixed in the overdrive position full-time. I still recommend running a cable to that lever to lock out the overdrive should you elect to. Another feature all of these transmissions have is free wheeling when in overdrive. When you let off the throttle the engine returns to idle, there is no engine braking when the overdrive is engaged. The thing to keep in mind with this if you accidentally leave the overdrive engaged when you park the truck you can roll backwards left in gear. Just make sure your solenoid is wired to something ignition hot.

Steve weim55 Colorado