First I'd like to say I've been a long time reader and the amount of information and willingness to take the time to share it is incredible! I haven't needed to post before because 99.9% of the information I needed was already covered, nor did I feel I had anything to add to the thorough answers given by others. Thank you.

My biggest endeavor so far is going to be adding an overdrive to a basically stock 56 f100 with rebuilt 292. It currently has a stock 3 speed manual transmission (3 on the tree) and I want to keep the column shift. I know this has been covered with bits and pieces here and there but I'm trying to put it all in one thread for my own sanity and to help others considering it.

Okay here's my dilemma, I have two transmissions one a T-86/R10 thin spline and a T-85/R11 with the heavy duty corse 10 spline x 1 3/8 dia input shaft. I'd prefer to use the T-85/R11 but On the T-85/R11 I would need to find yoke, adapt clutch arm throw out bearing (if that can be done?) and possibly the bell housing. I have everything on the T-86, yoke, bellhousing, clutch arm and throw out bearing. The bigger problem is these are both for a car and I want to install one of them into a 56 Ford pickup behind a stock, rebuilt 292 Y- block. I will be using the overdrive for freeway use primarily. I will not be trying to setup the overdrive as stock with all the governors, kick-down switches etc. but a simple toggle switch and OD cable.

From what I've been able to gather from my research is the pickup bell housing is approximately an inch and a half longer than a standard car bell housing requiring a longer input shaft/ main drive. Also the pickup bell housings has two mounting tabs on pickups before 1964. After 1964 Ford went to a standard 3 point mounting system like in the car. So as far as I can see I have only a few options;

1) Replace the input shafts with longer input shafts if I can find one.

2) Switch to a 3 point mount system and use a car bell housing.

The information I haven't been able to figure out for replacing the input shaft/main drive to one long enough for the pickup is;

Is the input shaft/main drive on an overdrive tranny different than the input shaft/main drive on a standard tranny?

If they are not different as long as I have the correct tooth count I should be able to swap for one that is longer correct?

For the T-86, Jeep used to these transmissions (as did many others), are the Jeep parts interchangeable with a Ford T-86?

Are there any other transmissions that I could swap input shaft/main drives with for either the T-86 or the T-85? I know some T-89 parts are interchangeable with the T-85 but none of the main drives I have found have 19T.

I understand that by swapping the input shaft/main drive I might have to shorten or otherwise modify it to work and I might need a new clutch disc.

If I used a three-point system with a car bell housing I would add a rear support for the overdrive extension (would do this with the truck set-up also) and probably keep the front mount. Would this work? I assume I'd have to adjust / modify the shift linkage due to the 1 1/2' bell housing difference.

I'm sure there are details I am missing so please enlighten me.

- Steve in Tranny purgatory

 

Hi Steve,

Welcome to FTE.

Wow did yo uever pick the subject for discussion.

Odd thing is I swapped out the C4 on the back of my 289 in my 55 with an overdrive transmission and all I had to do was buy a bell housing. First one I found fit. I never had all these measurement problems. Guess I was lucky

There was of course an Overdrive Transmission option on the 56 truck from the factory. And that continued on for many years. I might orient my research on the dimensions of those parts (ie find some one who has one and ask for measurements) and try and find them or acceptable substitutes.

 

Hi Julie, thanks for the welcome. Yeah I know it's a challenging Subject but I am making some progress. It seems from a few people I spoke with who work on these transmissions that you can use the Main Drive from a standard transmission in an OD Transmission. It also is possible to use a Jeep or GM main drive in a for transmission. So I think I found one from a GM application that might work with slight modification (shortening).

Steve

 

How did you make out with input shaft??? I am trying to put T85 in my 56. what did you use??

 

Gr8 56, it sure is nice to hear of someone trying to keep their truck basically stock. I highly recommend the overdrive option.

The stock pickup overdrive transmission was the same as the car for each year with the exception of the input shaft. You should be able to take a 1956 Ford car overdrive transmission and swap the input shaft from your current truck transmission in. I would measure this to verify that the car transmission won't simply bolt in as is.

Another option is to have either the input shaft bearing tip extended with a press on extender or have a longer pilot bushing made. I used the longer pilot bushing on a 1966 F-100 I put a T85/R11 combo into. That transmission had a car gear set with the shorter input shaft. Since I was swapping out the engine at the same time I mocked everything up before I put it in the truck. I made sure the shorter input had full spline engagement with the clutch disk. I had a local machine shop turn a bronze bushing for the input to run it.

With the T85, be aware that the only longer input shaft was with the 1965-1972 truck overdrive transmissions. These gear sets are hard to find and have a wider ratio than the car gear sets.

Edit - I just realized the original post was old. The info I posted is still true, but probably not helpful to the original poster. Oh well.

 

Thanks, it is a big help to me, I am trying to put a T85 in a 56 panel. I am trying to get everthing together before I remove the old 3 speed. I am getting an education. I might try to mock up the trans to another eng I have from another truck. the T85C-1A I just aquired is from 61 or 62 galaxie. it has the right 10 spline, but is about an inch to short. I like the idea of a longer pilot bushing. I never heard of a press on extension, Is that a machined piece?? I have the coarse spline driveshaft yoke, I will have to make a bracket for clutch linkage

 

The press on extension is a trick one of the local transmission rebuilders in San Antonio uses. You use a lathe to turn down the pilot end of the input shaft. You use the same lathe and make a press on extension. Leave the outer diameter a little large on the press on extension when you make it. Press the extension onto your turned down input shaft. Put the shaft with extension back into the lathe and turn the outer diameter to the needed size.

I recommend the longer bushing.

 

Thanks, I will try to go with longer pilot bushing

 

Sure it's an old thread i remember ready back then. Nothing wrong with bringing it back up, it had some information i was looking for a few months back, but i was unable to find it. The search feature does not work well for me on here.

 

The only F100's that came with T-85 O/D's were 1965/71's with 240/300 I-6's, 302/352/360/390's.

1953/64 F100's were available with the Warner T-86 O/D. The T-86 car extension housing has a flange on it, the trans steel/rubber insulator bolts to the crossmember, then to the flange.

F100 T-86 extension housing doesn't have a flange, because the trans is mounted via the 2 "ears" on the bell housing.

 

The car extension housing works fine in a truck. Use the truck bell housing and its the basically the same, its n ot "correct" but it functions perfectly.

 

I have a T86, but I was going to try to use the T85. If I can get a longer input shaft, or An extended pilot bushing, I think it will work. If all else fails, I can use the T86. I think the proper Input shaft is available for the T86. I am running a 312, and want to keep the stock bell hsg

 

Did you have any luck finding an extra long pilot bushing? I'm wanting to install a T85 behind a 223 in my '55 F100.

 

Im about to take on this challenge also. I have a '56 F100 with the original 223 and 3 speed. I have located a T85/R11 and plan to install soon. I am simply trying to gather all the parts before I dig in so the truck is on the jack stands for as short of a time as possible.

I would really benefit from your experience installing into your '55 if you have completed this conversion.

Thanks in advance...

 

Im doing this too!

My truck is a 63' Mercury with a 223 standard duty three speed. I've found a 51' Ford car with a eight cylinder & a three speed overdrive. I assume the cars overdrive is a T-86.

Im going to swap the electrical components to 12V components. Then Im going to get a shop to take my trucks standard dury three speeds input shaft and put it on the cars overdrive transmission and install! I will also have the shop shorten my drive shaft as necassary too.

Do i sound like I have my ducks in a row?

How have some of you taking on ghis challenged faired?