Re: 3 speed overdrive!!, now about getting it in.......
 

Thanks, I will look again at mine tonight.

Re: 3 speed overdrive!!, now about getting it in.......
 

Here is the gear housing from my regular three speed. It will go in to the overdrive but it doesn't look like there is any room for a gear. The pic is the housing without a gear. It seems like it's a little to long.

http://img.photobucket.com/albums/v3...psrhrnmelh.jpg

http://img.photobucket.com/albums/v3...psjao0klen.jpg

Re: 3 speed overdrive!!, now about getting it in.......
 

Witch one do you need? the long or short I have both.pm me

Re: 3 speed overdrive!!, now about getting it in.......
 

I finally got my wiring done exactly like the above pictures minus the colors. When I activate the switch I get power to the governor (86). I am not getting power to the solenoid (87). Where am I suppose to get power to? I have all three gears when the lever is forward and when it;s pushed back I don't get anything. Need a little help please!

Re: 3 speed overdrive!!, now about getting it in.......
 

This is how mine is wired
grounding the soliniod thru the governor will turn on the soliniod at approx. 25 mph and off when governor kicks back off at approx. 25 mph
the manual toogle switch is in the line coming from the governor so you can bring it out of o/d manually.
I took 12 volts from the ign side of the fuse blk. power on only when the key is on.
This works pretty good.

Re: 3 speed overdrive!!, now about getting it in.......
 

Mine is close. I have the battery going to 30 and the ignition is going to 85. Something is wrong when I put the lever in the OD position. The wheels barely turn. It's like it's not fully engaged all the way. When I have the lever in the three speed mode works great. Power is going to 86 to the governor when the switch is activated and I guess it grounds out when to gets up to correct speed. Then it will send power to the solenoid?

Re: 3 speed overdrive!!, now about getting it in.......
 

well ,What do ya mean when you say you have power to the governor.
the only thing the governor does is ground the sol. which is huge, cause that's what completes the curcit at the sol. if you disconnect all power to sol. you should have gears with the lever in or out. simple test is to run a wire straight from the batt. to the sol. when ya touch sol. post you should hear it kick in and out. I ran my trk with a wire like that with a h/d switch in the wire for a couple years and just clicked it in manually. worked ok. just remember ya can,t use reverse when the sol. is engaged. anyway if the sol is clickin in when the lever is in o/d and the rpms come up and the trk barely moves then the trouble is probably inside. maybe the roller clutch is wore out. which is pretty common. every unit I ever tore apart, only 3 or 4. the clutch was the one part that always looked pretty wore out.

Re: 3 speed overdrive!!, now about getting it in.......
 

When I flip the switch the power from the relay goes to 86 not 87. So I have power to the governor not the solenoid 87. I might also have a bad relay. I have it wired exactly the way as everybody else. I think I have something wrong inside. I only have 3 gears when the lever is forward.

Re: 3 speed overdrive!!, now about getting it in.......
 

Oh snap! there is a different wiring setup for HEI? - someone please elaborate. I bought a SM319 a few months back along with harness and an extra nos gov. was looking to put this in for my winter project. I was planning on using the extra dimmer switch config. From what I read here that won't work with HEI.

Re: 3 speed overdrive!!, now about getting it in.......
 

Sorry, I haven't given this any further attention since I wrote that post. The 319 I bought via Craigslist turned out to be crap. The countershaft drive gear is missing an entire tooth and the cost of replacement gears is rather high. I set it aside for a while to help me forget how much I paid for a parts core.

Good luck.

Re: 3 speed overdrive!!, now about getting it in.......
 

I finally got around to installing one of the OD transmissions I bought 2 years ago. One of the units had been behind a big block and several gears had been damaged from burnout abuse, but the owner said the OD worked well. The other unit looked in very good condition but he knew nothing about its history. I unfortunately gambled on the unknown tranny! I wired everything up according to the info here in the above posts and went for a test ride. I didn't have a cable for the lockout so i left the trans in OD. The first thing I noticed was the freewheeling which made a huge difference in the truck not lurching back and forth creeping down my driveway. Out on the highway the unit shifted nicely and the OD dropped in as it should. What a difference at highway speed! Everything seemed to work great until my 3rd trip out when I heard a whineing crunching noise (you know the one you never want to hear). I pushed the clutch in and noticed my OD was gone as well as the freewheeling. When I got home I noticed the lock out lever had no spring resistance at all, it still moved into the lock out position but the amount of throw doesn't compare to the other trans I have. So the question is could that lockout shaft have moved forward (for some reason) and not be returning with the movement of the lever? Anyhow I have replaced the front half of the other trans and will swap it with this one and try again!

Re: 3 speed overdrive!!, now about getting it in.......
 

Wow, pretty old thread but very interesting.

I've been trying to decide on a way to make my truck get better mileage and be able to run at 70 mph on the interstate without blowing up the engine. Everything from changing the rear end gears to installing a 5 speed on the floor. I think I'm going to go this route. It may cost a little more but I won't need to get rid of the column shifter and the truck will still look original. Now to start the search for parts.

Re: 3 speed overdrive!!, now about getting it in.......
 

You can wire it up not needing engagement cable or foot switch. My installation in 63 C10 went like this:

Used side plate (4-bolt) and shift arms off original three speed. This allowed the use of stock shift linkage arms.

Wired with toggle cut off / cut on switch for solenoid. Now when I want overdrive, flip the switch to on, accelerate to about 30MPH, let off gas and she shifts into OD. Gotta Love It.

Wiring diagram attached:Attachment 1766877

Re: 3 speed overdrive!!, now about getting it in.......
 

I think the parts search is just about done. I just bought this one.

Re: 3 speed overdrive!!, now about getting it in.......
 

The transmission arrived and it is now installed in the truck.
I also ordered and received all of the correct components that go with it. The kickdown, switch, overdrive cable and expensive relay.

Does anyone have any photos of where the relay and the kickdown switch should be mounted??
I know the switch goes under the gas peddle but a measurement from the bottom of the peddle would be nice. I also know I can mount the relay in any convenient spot, but I would like it to look original to the truck.

Re: 3 speed overdrive!!, now about getting it in.......
 

I can't help with pictures. As posted above I didn't use pedal switch and put the relay under the dash to here wires. By the way, noticed you are a neighbor (almost). Hello from Mississippi

Re: 3 speed overdrive!!, now about getting it in.......
 

We put one of these 3-speed overdrives in Dad's 66 last winter. Dad wanted a relatively stock looking installation but we couldn't find any info in the 60-66 truck assembly manual or any photos of a factory original installation. So we did the best we could based off info I was able to find in the 67-72 truck assembly manual and some 60's Chevy car assembly manuals.

The assembly manual shows the 67-69 trucks had the overdrive relay mounted on the inner part of the driver side front fender, near the top, back near the firewall. Obviously, the inner fender design is considerably different in those years so we just chose a similar location near the rear of the driver side inner fender on Dad's 66. I found a heater blower relay for various 60's/70's GM applications that had a similar look (metal case) and used that in place of a hard to find & expensive NOS overdrive relay.

I think Ford (and possibly others) mounted their kickdown switch under the gas pedal. But all the illustrations I found in the GM assembly manuals showed them mounted to a bracket by the carburetor. In keeping with the "somewhat stock" looking theme, I found a reproduction/replacement switch made for Studebaker applications that looked similar to the GM switch (except for the terminals). I made a home-made bracket (that attaches via the left rear carburetor mounting stud) and positions the switch so the throttle lever on the carburetor depresses the switch plunger at wide open throttle.

Re: 3 speed overdrive!!, now about getting it in.......
 

I am fairly certain that my truck had one of these trans from the factory, but the PO removed everything except the lockout cable and the relay (still mad about that because now I need to find one :mad: ). My relay is mounted to the inner fender right under where the proportioning vale is. I have also seen a 65 c10 with this trans from the factory and the relay was mounted on the firewall between the MC and the recessed area for the engine. Kinda right where the PO ran that black wire for the trailer brake controller that was added on in the 90s ish. Sorry I don't have any better pictures, I'm in college and the truck is at home waiting for me to return so that I can finish the engine swap.

Re: 3 speed overdrive!!, now about getting it in.......
 

Totally old post, but that was my wiring schematic on page 3 post 74 and that was to use the governor. To set it up w/o the governor is:

Re: 3 speed overdrive!!, now about getting it in.......
 

Also to put a Saginaw o/d in place of the old 3 spd you need to modify either the shift arms or the shift rods. I had one in my old '64 panel and I modified the shift arms. The last pic is the bracket I made to hold the cable and toggle switch. Ford repos an overdrive cable that has a solid handle and the right thick wire. If your going to an o/d from no o/d you will need to shorten the driveshaft and lengthen the speedo cable (I had an extension made). I finally found another Saginaw o/d to put into my '56 panel.

Re: 3 speed overdrive!!, now about getting it in.......
 

Just got an SM 319 and I'm missing the speedo bullet. I need the long version if you still have one.. Looks like the guy didn't disconnect the speedo cable when he pulled the engine.. the plastic gear is in there but the bullet didn't make it..
I'll PM you as well. Just wanted to revive this thread for others.. :gmc2:

Re: 3 speed overdrive!!, now about getting it in.......
 

I like this idea. I'll have to try this instead of the kick-down switch..

Re: 3 speed overdrive!!, now about getting it in.......
 

I also like this idea. I haven't been happy with the performance of the kickdown switch. I don't like that it tries to kickdown even when I'm locked out of overdrive. Go full throttle and then bog because ignition cuts out...

I'm going to build a bracket to mount the switch under the dash along with the switch I have to cut power to the whole system. That way, it's all in one spot and I don't run the risk of accidentally hitting the floor switch with my foot

Re: 3 speed overdrive!!, now about getting it in.......
 

I'm also leaning towards not using a kickdown switch on my install, but instead put a manual switch in a convenient location.

Over the years, I've had several British sports cars with overdrive plus I'm currently rebuilding a '64 TR4 with overdrive. These cars have a column mounted overdrive switch that looks like another turn signal switch but is mounted on the opposite side of the column. This is a really handy arrangement for engaging/disengaging the overdrive because you can control the overdrive with your finger without removing your hand from the steering wheel (sort of like lever mounted cruise control on some cars).

So, I was thinking that a switch mounted on either my truck's column mounted shifter or on the turn signal lever might be a good way to go. Seems like a push-button on/off switch would be ideal, but I haven't started looking for one yet.

Re: 3 speed overdrive!!, now about getting it in.......
 

My kickdown switch works good, I just don't like how it functions in relation to the throttle. I'm just planning on relocating the kickdown switch that I have with the current wiring to under the dash instead of being on the carb