Hi, I have a 66 F100 with the 3 on the tree and the OD. My question is how do I use it do I push in the clutch and push the lever in like it was forth or do I set it before I take off. Is it shift on the fly or what. I know it works because the first 2 weeks it was on and I had no back pressure.Thanks alot this site rocks, check out my photos.

 

Mater66, first off WELCOME to the site. I am amazed at the amount of wisdom that flows forth from the members on this site. I really think that there are no problems that these guys cant solve when it comes to the 61-66 F series trucks.

The only experience that I have had with an overdrive the cable was frozen and since I bought it for parts I never used it. The previous owner of the truck said that with the over drive and his 240 I6 he got 20 mpg on the highway.

I would imagine the guys on this site will be chiming in soon. God Luck and welcome.

 

mater66 Welcome to FTE and the 61-66 forum.

One of our well informed members will be buzzing through shortly, and will be able to help.

John

 

The OD lever can be pushed in or left out on the go, but it is best to do so while stopped until you get used to it.

It's a fairly simple factory setup. You activate the ABILITY to use OD with the OD handle. The governor (round cylindrical thing on the passenger side of the OD housing) keeps the trans out of OD under about 35 mph no matter if the underdash handle is pushed in or out. Above 35 mph, with the OD activated by the underdash handle, the governor allows the rest of the OD mechanism to work.

At normal cruising, the governor signals to a relay that it's okay to shift into OD. The relay cuts out the ignition spark momentarily to release pressure on the transmission's OD input shaft. Meanwhile the OD solenoid (round cylinderical thing on the driver's side of the OD housing) is allowing the OD to engage. That's when you feel it shift.

Now, when you mash on the footfeed, say to the floor, the accelerator linkage strikes a cutout switch which causes another interruption of the ignition, cuts power to the solenoid, and in an instant you're out of OD and back into direct drive. As soon as you back off on the accelerator, the cutout switch is released and you can go back into OD when you're above 35 mph. When you slow down to under 35mph, the governor takes over and kicks you out of OD so you have engine braking.

Pretty neat, huh? Works great AS LONG AS... the cutout switch works, the relay works, the ignition momentary ground works, the governor works, and the solenoid works. And, it's so simple and well made that it all usually works, unlike today's "gee-whiz, Uncle Jed, looky here at this doo-dad!" auto tech stuff. But if it's out, you revert to direct drive until you fix it.

An option that I like is to eliminate the cutout, the ignition ground, the relay and the governor and most of the factory wiring harness. I rig a small toggle switch onto the column shift lever and use it to control the solenoid ONLY. I still have the underdash OD handle and use it to enable OD, but toggle the actual in-and-out of OD with my thumb on the new switch. This way I can use OD to split shift between 1st, 2nd and 3rd gears if I so desire. BEWARE IF YOU DO THIS! YOU MUST, I SAY MUST, BE SURE TO TOGGLE OD OFF BEFORE USING YOUR REVERSE GEAR OR YOU'LL DESTROY THE OD OVERRUNNING CLUTCH!!!!!! DON'T FORGET!!!!!! See? There's a GOOD reason for all the factory OD features!

For additional info, check out....

http://www.tocmp.com/manuals/trans/B...age_03_jpg.htm

 

WOW thanks so much for all the information. I was wondering what that switch above my gas pedal was for.Thank you.

 

This is actually a quote from an earlier thread. Its from a couple of years back when I was puzzled by the overdrive. Now everything is second nature and it is the greatest thing in the world to me. I personally think that the Overdrive trucks should command a signifigantly higher resale value. Maybe they do. I havent seen enough for sale to know. It really makes the truck a lot of fun to drive and with todays ripoff gas prices you cant go wrong with the overdrive. Well thats not true. You COULD forget to set the parking brake with the OD engaged and watch your truck roll away into oblivion. Yes, overdrive can KILL you!! Read the post through and see why......

Overdrive-Ford Truck

These overdrive trannies are great,I've had one for over 20 years. BUT FIRST SEE MY DANGER WARNING FURHER DOWN!
To answer your question, if the overdrive (OD) tail housing has R-11 cast into it, it will hold up quite well. What it WON'T tolerate well, though, is goofing off, popping the clutch, etc. Originally, it came with a 2V carb, so I mention this reference the 4V. It is designed as a working man's way to save on gas, yet get decent performance. I have one in my '66, and I really like it.

You have two electrical items on your trans: The upper one, on the passenger side, is the governor, and the lower one, on the driver's side is the actuation solenoid. You have a number of other items, so I'll describe them as well. This is, of course, a factory intallation I am describing. If yours was transplanted, it may not be all there.
This is a Warner T-89N transmission. It is essentially a T-89 3 speed with an OD attached. It differs from the T-89 in that the T-89N has a few modifications for the OD extension to work.

1. Your governor closes the main circuit when your speed gets high enough, usually about 27 mph.

2. This activates a internally fused relay, which is on your firewall in the engine compartment above the main wiring harness port. The relay
energizes the primary circuit in the solenoid.

3. When pressure is removed from the drivetrain by taking your foot off
the gas momentarily, the solenoid drives home a pawl to lock in the OD sun and planetary gears. Once the pawl is in, an internal switch in the
solenoid turns off the main circuit, and uses a less powerful circuit to hold the solenoid in. Thus the need for 2 wires. In other words, the way it works is this: Get up to about 30 mph, take your foot off the gas, listen/feel for the "clunk", and drive on at a lower rpm!

4. When the engine starts to bog down (because in high gear, a heavy load going uphill for example), your increasing pressure on the acclerator will activate a kickdown switch under it. This switch momentarily does 2 things: It kills the engine by grounding out the coil, and kills power to the solenoid. This allows the solenoid to drop out, effectively lowering the gears ratio, and giving you more power.

5. Occasionally, you will not want the OD to activate. While stopped, pull the handle under the dash marked "Overdrive". this engages a mechanical lever which internally locks out the OD, and keeps it in gear.

WARNING! WARNING!
THIS OD TRANSMISSION WILL NOT HOLD UNLESS IT IS IN REVERSE GEAR!

The OD unit has what is known as a overrunning clutch in it. That is, if the wheels are turning faster than the gears in the transmission, the wheels are allowed to FREEWHEEL. This is dangerous because if the truck is in any gear but reverse, it WILL ROLL, even if it is in gear! ALWAYS, ALWAYS, get in the habit of putting it in reverse before you touch the keys.

I loaned my truck to my dad, and it rolled backwards, in first gear, with the door wide open. The door caught a tree, and bent the door pillar so far back the windshield leaks, and it isn't fixable.Also, if you carry a heavy load, MAKE SURE your OD system is working. If not, pull the handle out, and live with the poor gas mileage. I had my solenoid die going downhill a number of years ago with 3000 lbs of stuff, which meant I had only my drum brakes to slow the truck down. I sure wish I had had disc brakes then for sure for sure!!! I burned up a set of brand new drum brakes that way, trying to stop, which I nearly didn't. When I say "live" with the poor gas mileage, I mean it. You may not otherwise!

Some other cautions: They have a tendency to leak, because the solenoid seal isn't good. Be sure to keep the transmission full. When you change the fluid, let it drain for a while, and then when you fill it, let it sit for a while between checkings. The openings between the main gearbox and the OD unit are sometimes small, and the 90W gear oil may take awhile to seep into the OD part of the unit. Also check the OD unit for any extra fill or drain plugs and be sure to use them if they are there. Enjoy! I get about 18 MPG at 75 MPH with my 352 2V V-8 and OD transmission, so it is WORTH the extra hassles!

Can the overdrive solinoid be removed without pulling the whole unit ?

YES Remove the two bolts, rotate the solenoid 90 degrees to disengage the plunger from the pawl, solenoid lifts out then. Clean everything under the tin cover. Take a length of welding rod and make a small loop that will engage the pawl, you should be able to move it in and out about 3/4".

The Overdrive Kickdown switches are available at

C & G EARLY Ford partS: 1932 - 1956 FORD PARTS
FORD All 1949-1959 Overdrive Kick Down Switch
8A-6918-B 18.00 Each