3 speed overdrive with an HEI distributor

[cwcarpenter98]

Originally Posted by NewBayColony

Do you have any pictures of where and how you mounted the lockdown switch? Thanks

I mounted the kickdown switch to the carb utilizing holes that were already there. I'm running a Quadrajet and I didn't have an original bracket, so I made my own bracket

[NewBayColony]

Originally Posted by cwcarpenter98

I mounted the kickdown switch to the carb utilizing holes that were already there. I'm running a Quadrajet and I didn't have an original bracket, so I made my own bracket

Nice! Thanks for the pictures. i have a 292 and a MonoJet but your setup gives me some ideas. Nice engine compartment.

[cwcarpenter98]

Originally Posted by NewBayColony

Nice! Thanks for the pictures. i have a 292 and a MonoJet but your setup gives me some ideas. Nice engine compartment.

Thanks, it's just a simple driver
I would love to have a 292, but I would do a full build on one before putting it in

[dschmit]

I am wanting to run a MSD ready to run distributer with a Blaster II separate coil. (I want to keep the look of the small cap.) Is there any harm in hooking the wire to the Neg side of MSD coil as it is was done originally?

[cwcarpenter98]

Originally Posted by dschmit

I am wanting to run a MSD ready to run distributer with a Blaster II separate coil. (I want to keep the look of the small cap.) Is there any harm in hooking the wire to the Neg side of MSD coil as it is was done originally?

I'm not sure as I have not had any experience with MSD products or how the original system worked with a factory coil. I got my overdrive trans after I put the HEI in. Maybe call MSD and ask them about it?

[dschmit]

Thanks, I was just a little curious.
I do have a email into MSD I'll see what they say.

[cwcarpenter98]

Originally Posted by dschmit

Thanks, I was just a little curious.
I do have a email into MSD I'll see what they say.

I just talked to my mechanic friend and he doesn't think it would cause any issues as the MSD coil basically acts the same as an original coil. My guess is that you would be fine, but hopefully MSD will have a more definitive answer

[spspspspoon]

cwcarpenter98

what's your engine u have quadrajet on?
any info on how u have it tuned?
still vac choke?

[cwcarpenter98]

Originally Posted by spspspspoon

cwcarpenter98

what's your engine u have quadrajet on?
any info on how u have it tuned?
still vac choke?

It's on a 283. I bought a rebuilt unit from Summit Racing that has an electric choke on it. I wanted the electric choke because I didn't want to use a hot air choke with the 68 manifold that I am using. I basically just slapped the carb on the truck, messed with the idle and mixture screws a little bit, and haven't touched them in almost 2 years. Haven't really had a need to do any tuning on it since I put it on and tuned it up the first time

[D'Monsta]

Thanks for all this great info from all of you fellas.. My '66 GMC with 250 has an HEI distributor now. The original SM 318 is popping out of 3rd and vibrating to the point that the windows and heater diverter are rattling so loud I can't hear the radio!.. I have 2 of the SM-319 transmissions with OD so my plan is to clean one up real good, inside and out, and install it.. If it passes the 'gears good' test, I'll activate the OD functions.. Will post updates here..

[cwcarpenter98]

Originally Posted by D'Monsta

Thanks for all this great info from all of you fellas.. My '66 GMC with 250 has an HEI distributor now. The original SM 318 is popping out of 3rd and vibrating to the point that the windows and heater diverter are rattling so loud I can't hear the radio!.. I have 2 of the SM-319 transmissions with OD so my plan is to clean one up real good, inside and out, and install it.. If it passes the 'gears good' test, I'll activate the OD functions.. Will post updates here..

Sounds like a good plan to me!





Update from Frankentruck:
Since I last posted on this thread, I was able to pick up a second overdrive transmission. That ended up being a good choice because not long after, the solenoid on the one in the truck started to fail. Swapped them out and haven't had any issues since.


No issues with the current wiring setup either.


There is one wiring thing that is not an issue for the overdrive, but I'm not fond of it when I'm not using overdrive. I prefer to drive around the small town of Milledgeville with the trans locked out of overdrive to take advantage of engine braking. Because of that, I added a toggle switch in the power wire that completely turns the power off to the system. The switch is on the power side, after the fuse, but before the main relay. That switch has worked great.
What I have noticed, and don't like, is that at all times, whenever the kickdown switch is hit, the ignition cuts. I can press the kickdown switch with my finger while the truck is idling and kill the engine. That also means that in lockout, if I want to go full throttle, I can't because I hit the kickdown switch and cut ignition.

I was thinking about adding an additional relay that keeps the circuit for the kickdown switch from actually doing its thing when I have the toggle switch mentioned above turned off. When I turn the power back on with said toggle switch, the additional relay will then allow the kickdown switch to do its thing when requested. That makes sense to me, so if I didn't explain it well enough, please tell me to explain my idea better

On the other hand, I'm curious as to why the kickdown switch does what it does when I don't have power to the system. Am I picking up power from the relay for the HEI that I haven't realized before? I don't know. I'm kinda lost on that one

[D'Monsta]

Hope all here have a great Christmas and Happy New Year..

I have installed my SM 319 and the gears are good.. I have installed a cable from dash to tail shaft to lock in and lock out the overdrive.. I do not have the wiring hooked up to relay, governor, solenoid, and kickdown but to test the OD, I have run a hot lead from a cigarette lighter plug in directly to the solenoid that I can engage and disengage manually from the dash like a switch.. I have run the truck up to 35 MPH, pushed the cable in and engaged the power to the solenoid by plugging in.. Pushed in clutch (to take load off engine) and then I plug in the power, let off clutch but no engagement of overdrive happens.. Shouldn't this method, in theory, be enough to get the unit activated for testing purposes? Might I have a bad mechanical unit in the tail shaft? I did test the solenoid and it does seem operating.. Do these tail shafts come on and off easily for examination and gasket replacement?..

[NewBayColony]

Originally Posted by D'Monsta

Hope all here have a great Christmas and Happy New Year..

I have installed my SM 319 and the gears are good.. I have installed a cable from dash to tail shaft to lock in and lock out the overdrive.. I do not have the wiring hooked up to relay, governor, solenoid, and kickdown but to test the OD, I have run a hot lead from a cigarette lighter plug in directly to the solenoid that I can engage and disengage manually from the dash like a switch.. I have run the truck up to 35 MPH, pushed the cable in and engaged the power to the solenoid by plugging in.. Pushed in clutch (to take load off engine) and then I plug in the power, let off clutch but no engagement of overdrive happens.. Shouldn't this method, in theory, be enough to get the unit activated for testing purposes? Might I have a bad mechanical unit in the tail shaft? I did test the solenoid and it does seem operating.. Do these tail shafts come on and off easily for examination and gasket replacement?..

Have the power connected before you push the clutch in. I'm not positive that will work but that is how it works when it is wired up in the stock configuration. Also you don't have to go over 30 if you are bypassing the governor.
Merry Christmas and Happy New Year to you, too.

[cwcarpenter98]

Be careful with the test wiring as you don't want to forget overdrive is engaged, try to take off in overdrive and risk damaging the transmission. The electronic system as a whole was designed to keep from damaging the overdrive components.

On your test wiring, which wire did you connect to on the solenoid? If the solenoid bench tested properly, it should work when installed in the transmission

[D'Monsta]

OK.. Overdive is working now with push/pull cable and pull out/light up switch.. I'm functioning as the governor, engager and kickdown switch with just that one pull out switch and it works fine.. I am, however, getting ready to add all the proper wiring..

Has it been determined that connectiing the Kick Down switch to the 'Tach" tab on the HEI works safely or is breaking the feed wire to the HEI the better way to go?

I also like the idea of not energizing the electrical system of the overdrive when not in use.. It seems to me that a double pole, double throw switch could take care of that with the hot and ground out wires run to their own terminals. When flipped one way, it would break both wires and when flipped the other, connect them back to themselves..

[NewBayColony]

Nice set up. You're gonna love it.

[bhap]

Mine is setup with a relay - it opens a normally closed 87A terminal (to HEI +) when the kickdown switch sends the 85 terminal a path to ground. No idea if the tach lead is safe. To be honest, I’m not sure the kickdown switch is any easier than letting your foot off the gas and pulling a switch to turn off power to the solenoid to achieve a “down shift”. My KD switch works, but it requires flooring the gas pedal and waiting for the solenoid to drop out. Much smoother with the switch.
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