Where does this belong?

[whatleyr]

Hello all. I'm looking over my engine compartment of my 1965 c10. Found what looks like a switch but can't find where it belongs. In the pic I'm pointing to the switch. It's hanging on the drivers side frame. Thanks.

[63burban]

Is the switch attached to the frame or just laying there?

[whatleyr]

No it isnt. It is attached to the wiring harness which goes into the firewall.

[63burban]

Looks similar to an overdrive kick down switch that mounts to the carb. Did the truck have a three on da tree ?

[whatleyr]

Truck is still 100% original. It does have overdrive. That is what I'm trying to get working. Where would that go on the carb? Also, can't get the overdrive lever to pull out at all. I thought they might be related.

[jdl71]

Can you see what colors the wires are and where they terminate at the other end? If so, I have a wiring diagram and we could start from there.

[whatleyr]

It's got black, red, orange, and green. Looks like the wire splits off at the firewall. Black orange and green go to a relay on top of the fender well next to the hood hinge. The other end looks like it goes down and connects to the transmission. Hope this helps.

[jdl71]

I was thinking that OD was a factory installed option, but I don't think that's correct now. I have the '63 shop manual, the 64 and 65 supplement, and the standalone 65 wiring diagram and none say a word about an OD. The only one I have not checked is the Factory Assembly Manual, but it's very hard to search as nothing is in any kind of order. I did find this thread that might be of some help:

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

Also you might look at the last pic on this site:

http://www.classictruckshop.com/club...over/drive.htm

Hopefully someone smarter than me will chime in shortly. Sorry.

[frankslagoon]

These things are a real pain to get wired correctly I been tryen to get mine " correct" for awhile. the gov. on nthe pass. side of the tranny controls the relay and the relay puts power to the sol. on the drivers side of the tranny. some where inbetween the kickdown switch kicks out the overdrive when ya depress the throttle all the way. I've got a few diagrams. pretty complex. I just have a wire goin from the fuse box to the sol. on the tranny with a switch and I kick it in and out as needed. I been usen it that way for a couple years now. You do need to free up the O/D cable or at least lock it in to have o/d. Anyway I have 4 of these things and have a highbred 4 speed with o/d on it in the trk right now. I can send ya a couple diff. wire dia. and I got lots of pics to.

[whatleyr]

Thanks everyone for the information. This was my grandfather's truck. He parked it in a barn the day he died, sat for thirty years undisturbed, and I was just given the truck last year. The truck was ordered from the factory with its overdrive installed. I don't know if it makes muCH of a difference that it is a in line 6 instead of the v8. Everything else on the truck works great except the overdrive and gas guage. Will look over the drawings and threads and see what I can come up with. I've showed the truck to several "classic car" mechanics and they all say "I've never messed with an overdrive before." Very irritating. Would love to keep the truck correct but it's not cooperating.

[whatleyr]

The kick down switch looks like it. Where was it originally mounted?

[63burban]

Mounted on the carburetor so when you back off the throttle it will kick into OD. I'm not familiar with these truck versions, my experience is on Tri-5 passenger cars. I actually have a 55 Chevy 235 with OD here right now but the brackets are different than yours would be. I can post a pic if that would help. when working properly these set ups are awesome. As a kid, all my dad ever drove were Ramblers with 3 speed OD and 6 cylinder engines.

[whatleyr]

Thanks 63brban. I would love to see a picture of an overdrive switch installed. I'm guessing that the bracket is what fell off. Any idea on how to get the cable free so I can pull the overdrive lever in and out? Thanks

[ray_mcavoy]

As jdl71 posted earlier, there doesn't seem to be a whole lot of factory documentation on the OD trans option in these trucks. It is listed as RPO M10 in the 60-66 truck assembly manual but the pages with details are absent. And it is briefly mentioned in the 66 shop manual supplement (just gives gear ratio specs and a reference to the 66 overhaul manual).

The OD trans did remain an option in GM trucks until about 1969. So there is some info in the 67-72 truck assembly manual.
Here are some scans of the pages that show the kick down switch. These probably aren't exactly the same for 60-66 but should be close:








As for the stuck lockout cable, try spraying it with some penetrating oil.
Also unbolt the lower end of the cable from the lever on the side of the trans ... that lever might be stuck from sitting so spray some penetrating oil on that too where it enters the trans.

[frankslagoon]

If you want my B/W Overdrive Service Manual PM me.

[Vortech]

Just curious if there is a thread on repairing the govener? I've got my OD wired directly to a switch with a direct ground. Works good, but would be nice to get the govener sorted out.

[frankslagoon]

Originally Posted by Vortech

Just curious if there is a thread on repairing the govener? I've got my OD wired directly to a switch with a direct ground. Works good, but would be nice to get the govener sorted out.

I have taken them apart . super simple inside. nothen will spring out on ya. I have a couple pics of them apart but can't seem to find them. I'll keep lookin. They just unscrew and the cover unscrews. probably have it gov. end up when ya take the lid off.check the gears that mess with the speedo drive gear and the gov. weights are adjustable. if I can't find the pics I'll pull one apart real quik and send pics.

[63burban]

Here are a couple pics of a 1955 Chevy switch on a 235. BTW this 235 with3speed OD will be for sale.

[frankslagoon]

Heres one off a Muncie 3sp. it"s got a different weight set then on my trk and no adjustment screw for the spring tension but probably closer to yours anyway. this is looking at the inside of the top plate

[SOUTHERN917]

All the manuals and info you could want on the O/D units, FREE!!!! http://devestechnet.com/Home/HowTo#driveline

[Vortech]

Great, thanks for the help!