I have a 1966 3 speed with overdrive in my chevelle wagon, after droping a small block in it, I can't get the overdrive to work. All wires are hooked up. The wire that was connected to the (-)side of coil is now connected to an acc. term. at fuse box. The switch that was mounted to the carb. is no longer mounted. I tried plugging it in (but not mounted to linkige) but still not working. The trans. free wheels when you let off the throttle and the overdrive lever is pushed in. I need somebody with some knowlege on these old trannys. Thanks in advance
kid
Kelly,
Was this ORIGINALLY a 3spOD car? If so, is the harness all there and intact? If the answer to that is yes, do you have a good connection at the relay and is the relay in good condition (the relay for an OD tranny looks kind of similar to a horn relay).
The OD normally does not engage until a speed of about 30mph is reached. But, actually, its not the vehicle speed which determines when OD is engaged, it's the speed of the tranny tailshaft. For example, MOST 3spOD cars came with a 4.11 rear. So, if your car had a 4.11, and you changed the rear gears to a 3.31, then it may be 40mph before the OD kicked in. The 3spOD trannys have both a govenor and an elec solenoid on the tail housing. At a certain shaft speed, the governor sends current to the relay, and then the relay sends 12volts to the solenoid to actuate a pawl that engages or disengages the sun gear (the sun and planetary gears is what makes the OD). So, after all this, it very possibly is NOT the tranny itself, but an electrical circuit problem. Make sure all electrics are connected, in good condition and check the solenoid (apply 12volts to the solenoid terminal) to be sure it is working (the kickdown switch on the throttle linkage serves to kick the tranny out of OD upon hard, full throttle acceleration).
As I'm sure you have noticed, there is also a mechanical shift lever on the side of the tail housing. This lever is engaged/disengaged by a cable with the handle mounted under the dash. Be sure this is going full travel. To test this, when the OD is engaged (handle pushed in), and you are driving down the road, let off of the throttle, the car should "free wheel". Shift it out of OD (stop the car to do this) and when driving down the road and letting off the gas, the car should be slowed down by engine compression just like a regular manual tranny would do (that's what you have when OD is disengaged).
Before I got my first Muncie, I drove a 3spOD and loved it (if you knew how to make one work, you could get 6spds from one)! But, unfortunately, the 3spOD was not up to the task of staying together behind a performance V-8. After a couple of rebuilds, I got my first Muncie. That was back in the 60s (but I still remember how they worked, kind of like riding a bike).
Was this ORIGINALLY a 3spOD car? If so, is the harness all there and intact? If the answer to that is yes, do you have a good connection at the relay and is the relay in good condition (the relay for an OD tranny looks kind of similar to a horn relay).
The OD normally does not engage until a speed of about 30mph is reached. But, actually, its not the vehicle speed which determines when OD is engaged, it's the speed of the tranny tailshaft. For example, MOST 3spOD cars came with a 4.11 rear. So, if your car had a 4.11, and you changed the rear gears to a 3.31, then it may be 40mph before the OD kicked in. The 3spOD trannys have both a govenor and an elec solenoid on the tail housing. At a certain shaft speed, the governor sends current to the relay, and then the relay sends 12volts to the solenoid to actuate a pawl that engages or disengages the sun gear (the sun and planetary gears is what makes the OD). So, after all this, it very possibly is NOT the tranny itself, but an electrical circuit problem. Make sure all electrics are connected, in good condition and check the solenoid (apply 12volts to the solenoid terminal) to be sure it is working (the kickdown switch on the throttle linkage serves to kick the tranny out of OD upon hard, full throttle acceleration).
As I'm sure you have noticed, there is also a mechanical shift lever on the side of the tail housing. This lever is engaged/disengaged by a cable with the handle mounted under the dash. Be sure this is going full travel. To test this, when the OD is engaged (handle pushed in), and you are driving down the road, let off of the throttle, the car should "free wheel". Shift it out of OD (stop the car to do this) and when driving down the road and letting off the gas, the car should be slowed down by engine compression just like a regular manual tranny would do (that's what you have when OD is disengaged).
Before I got my first Muncie, I drove a 3spOD and loved it (if you knew how to make one work, you could get 6spds from one)! But, unfortunately, the 3spOD was not up to the task of staying together behind a performance V-8. After a couple of rebuilds, I got my first Muncie. That was back in the 60s (but I still remember how they worked, kind of like riding a bike).
DZAUTO, Thanks for the informitive reply. I did not notice a relay, so I need to investagate more. The car came with the OD. I only changed the motor from a six to an 8 cyl. (but had the complete front end off during rebuild) The harness appears to be all there and intact. where would the relay be located? When reinstalling the harness, I don't recall attaching any wire to a relay. The tranny works like you stated (freewheeling) I contacted the previous owner, and he stated that the OD worked before. I must be overlooking something. Armed with your helpfull info. I will dig into it again after work tomorrow. Thanks again. P.S. I see your from Ok., will you be going to the Chevelle carshow/drags at MID America (Ark City)next month?
Kid,
Trace the wire harness for the OD up to the engine compartment. You should eventually come to a connector (I think it had 3 terminals) which plugs into the relay. As I said, the OD relay looks quite similar to a horn relay. In fact, some cars had the horn and OD relays close together.
I had not been aware of the Ark City event. I'd love to go, BUUUUUUUUUUUUUUUUUUUUUUUUUUUUUT, we just got hammered with our taxes ($3400) and I will need to put back every penny for CB03 after I pay taxes, so that will probably leave Ark City out. What are the dates?
Trace the wire harness for the OD up to the engine compartment. You should eventually come to a connector (I think it had 3 terminals) which plugs into the relay. As I said, the OD relay looks quite similar to a horn relay. In fact, some cars had the horn and OD relays close together.
I had not been aware of the Ark City event. I'd love to go, BUUUUUUUUUUUUUUUUUUUUUUUUUUUUUT, we just got hammered with our taxes ($3400) and I will need to put back every penny for CB03 after I pay taxes, so that will probably leave Ark City out. What are the dates?
DZAUTO, the date for the chevelle drags is April 26. I found the relay, but did not have any juice to it. From looking at the existing wireing, there was a jumper wire from the horn relay (about 3" away)but had been melted. I wired the two together, then proceeded to melt the black wire going to the solenoid, when I put it in high gear. Now I think the solenoid has a short in it(tried to apply 12 volts to it and shorts out). My next step is to find another soleniod. Your knowlege has been very helpfull. Hope you can make it to the drags. I will be there with my son and in our red 66 chevelle wagon (lowered with Keystones)
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