I got me a 3 speed overdrive!

[62 Barnfind]

I went to pick up a donor cab today for the 58 i'm working on and found a transmission. It's a GM 3 speed with overdrive and I got it for $100. I want to put it on my 62 so I can drive a little easier on the highway with my 235. My question is will it work and what is the extra lever for toward the rear of the trans? Here is the pics and the serial number. Any help would be great! We also picked up a nice 55 GMC factory V8 with Auto, two 50s fords and a 41 Chevy truck. It was a great day!

[Marv D]

The lever is a 'lock out' to lock it in direct / 1:1 under drive. You have to move the lever to the rear (as I remember) to allow the sunshell OD unit to engauge. The big canister on the side is a 'kickdown' solenoid so to speak. Apply 12v and it will shift out of OD and back in to 1:1. But the thing didn't have enough power to pull it out of OD under load,, you have to es out of the throttle to allow it to kick-out. There is a governor on the toher side that is a finicky ordeal. Make sure the flyweights are not rusted up or it won't allow it to go into OD.
These things are getting as rare as hens teeth. If it's in good shape they bring a small fortune. GREAT find for $100 (potential to make 5x or more your investiment)

But be aware, the OD unit is pretty fragile. It also doesn't take kindly to 5000RPM launches even on hard tires (LOL I bet I tore up 100 of those things in my first vehicle)

[c20 diesel]

The lever toward the rear is to lock out the overdrive,It hooks to a push pull
cable under the dash. Cable in for overdrive , cable out works like a three speed. with out over drive will, not free wheel

with the cable pushed in for over drive.
Must use REVERSE when parked. the forward gears will free wheel
the truck will roll.

[slorio]

C20:
Here is a link with the original manuals where you can read all about it. I have the later model with synchro first gear and seven bolt side cover. See Drive Line Related links. I think they are a great upgrade for our trucks.
Regards,
Steve
New Orleans

http://devestechnet.com/Home/HowTo

[62 Barnfind]

Thanks for helping me out. I have been looking for one of these things on line for a little while and wouldn't you know it I almost tripped on one. From what I read I will also need to shorten the drive shaft little, add a relay and white it up. I saw one in a truck before and the guy just had a toggle switch to turn it off and on. Can I get away with that or do I need to wire it the right way? Also I need to find original pull cable for the lock out. Any Ideas?

[slorio]

62:
For the cable, a PTO cable works fine. That is what I have on mine.

On the wiring. I used a push/pull switch on the dash to turn it on and off, but the switch controls a relay. Wiring only through the switch is too much amperage for it. I also used the governor to trigger the relay. The governor kicks in at about 30 MPH which closes the relay. When you hear it click, you ease off the gas and it shifts to overdrive. Mine shifts to overdrive in second gear. I never turn it off. Around town it saves me a shift to 3rd unless I am over 45 MPH. The originals had a micro switch on the carburetor that kicked out if you floored the gas. I didn't see a need for that one since the push/pull switch on my dash does the same thing if I want to switch the overdrive off.

Hope that helps.
Regards,
Steve
New Orleans

[Gianyveedub]

Check out this page...

http://67-72chevytrucks.com/vboard/s...d.php?t=313886

[62 Barnfind]

Thanks everybody for the info. I didn't get where and what really to buy? I think I understand everything else. I'm planning on running the push pull cable where my manual choke is because I now have electric chokes on my carbs. I will also run a toggle switch as in the attached tread that Gianyveedub provided. I still need to check out the trans and see if its good. I went to pick up a 40 pickup and left the trans in the garage.

[cv65]

something to read http://chevy.oldcarmanualproject.com...55csm0715.html

GO ARMY! former f troop 17th cav 196th light inf americal div 1968-72