Overdrive or Not
Thread Starter
|
Freshman User
Joined: Jul 2004
Posts: 39
Likes: 0
Overdrive or Not
I have a 66 F-100 that had a 352 engine with a 3 speed overdrive transmission. The previous owner removed the 3 speed overdrive transmission and replaced it with a regular 3 speed transmission. I replaced the 352 engine with a 390 High Po. I did change it over to power steering and found a power steering column with three on the tree. My question is if I locate and install the original overdrive transmission can it hold up to my new engine? I heard that the overdrive transmissions were weak and that is why so many were replaced with the regular three speed. Thanks for all your help.
Senior User
Joined: Oct 2003
Posts: 123
Likes: 0
From: Monroe, LA
There is a reply to a similar question in this forum, "65 Overdrive Trans", posted by banjopicker66, that goes like this:
Originally Posted by banjopicker66
[updated:LAST EDITED ON 27-Aug-02 AT 07:04 AM (EST)]Brian: 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 30 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!
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 30 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!
New User
Joined: Sep 2004
Posts: 8
Likes: 0
overdrive
Thanks for the information. But I don't think my overdrive is working, yes it freewheels when the level is in but I don't get that 'clunk' when I release the gas pedal. Wonder how you check if the solenoid or any of the electical items are working. I'll drive it tomorrow to work and see if your instructions work. Thanks....Rick
!["Beemer Nut"'s Avatar](data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 50 50'><circle class='avatar-circle-default' fill='%23bc5285' cx='25px' cy='25px' r='20px'></circle><text class='avatar-text-default' x='49%' y='53%' fill='white' text-anchor='middle' alignment-baseline='middle'>"</text></svg>)
Post Fiend
Joined: Dec 2003
Posts: 6,658
Likes: 4
From: "Islander"
To OD or not OD that's the question, (not drugs)
Ford Blue, way back in my past i converted a T-86 3-speed box, (machined the rear case opening larger for OD adapter to have OD. The OD unit i installed was a R-12 that had 4 planetary gears vs 3 planetary gears in the R-11, 33% stronger vs the 6 cylinder R-11 unit. This same unit (R-12 OD) was later installed on a Turbo 400 trans for highway use with a 3/4" adapter plate that i machined. The biggest problem i had with the OD unit was the OD solenoid sticking because of the pawl. Also check your linkage, there should be a alignment hole in the shift linkage that will take a 3/16" rod then adjust the linkage. The contacts in the governor at times will get dirty, this prevents getting OD. In my "stupid i can improve it days" i ran the box as a 6-speed forward and 2-speeds reverse and i never broke it. I may be backwards, R-11 weaker or stronger than R-12? 4 or 3 planetary. Carl....o&o>....
Senior User
Joined: Aug 2004
Posts: 498
Likes: 0
Can the overdrive solinoid be removed without pulling the whole unit ? their are 2 bolts holding the solinoid in. I beleve this is where my problem is also, I get voltage to the solinoid but only hear a slight click. i noticed the goop on the input wires was detached from the case makeing it possabull for mosture to get in. But the area appears to be clean and no eveadence of rust or corosition.
Last edited by jav409; Oct 11, 2004 at 01:24 PM.
Senior User
Joined: Aug 2004
Posts: 498
Likes: 0
Ok I just received my 1966 ford Shop manual on CD, it has a complete section on the 3 speed overdrive, the cover can be removed while still in the truck and it has a pic of the contacts and test to be done, will do the tests tomorrow night if time allowes and post on what I find.
Trending Topics
Post Fiend
Joined: Dec 2003
Posts: 6,658
Likes: 4
From: "Islander"
OD solenoid
Java409, 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". Carl....o&o>....
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 6 Best Deals Available on New Fords & Lincolns Right Now
Brett Foote
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Verdad Gallardo
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
New User
Joined: Sep 2004
Posts: 8
Likes: 0
Spoke with an electrican and he said my switch at the gas pedal is bad, so I'm going to replace it but I went to an auto parts store and they couldn't help me. Do you know where I can get one? Thanks for all the input.
Senior User
Joined: Oct 2003
Posts: 123
Likes: 0
From: Monroe, LA
There is an overdrive kickdown switch on ebay right now
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2494031803&rd=1&sspage name=STRK%3AMEWA%3AIT
2 bids, 1.25, 6 days, 2hr to go.
go get it!!
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2494031803&rd=1&sspage name=STRK%3AMEWA%3AIT
2 bids, 1.25, 6 days, 2hr to go.
go get it!!
Thread Starter
|
Freshman User
Joined: Jul 2004
Posts: 39
Likes: 0
Overdrive or Not
I don't know why the previous owner took the overdrive transmission out of my 66 F-100 SWB before I bought it. I would suspect that he had trouble with the overdrive transmission because he replaced it with a long wheel base 3 speed transmission and left the same drive shaft that fits the overdrive transmission. If an overdrive transmission will hold up to my engine I will return it to the original overdrive transmission. If the overdrive transmission is going to give me problems and I have to try to locate parts for it and repair it, I will just find a regular 3 speed transmission and change the drive shaft. I have heard that there is a company that rebuilds these overdrive transmissions. Are the rebuilt ones a lot stronger than they were originally? I do not race my truck or pop the clutch but I do need a transmission that will hold up to my engine preformance. Any suggestions? I need to start thinking about fixing my mismatched transmission and drive shaft.