I'm thinking of replacing the FOM in my 56 with aT86 overdrive.Any of you guys that have done this swap think that my 3.22 gear is not enough with a stick?This not a race car,just an almost every day driver,so I'm not concerned about off the line launches.I just want to make sure it will take off without any shudder.

 

Paul,

Boonville,MO

Paul:

I don't think you will have a problem taking off with the 3.22, but you may have to kick it out of overdrive often on the highway if you are in hilly country.  I'm not good at geography, but I do know the Ozarks are in Missouri.

John - "The Hoosier Hurricane"

If you can find one a 6 cyl OD trany it may have a lower first gear ratio (higher numerical value).  This would be an advantage with the 3.22 rear axle set.  Also you would probably be happier with an axle ratio of about 3.50 to 3.70 or so no matter what since it would make initial starting from a stop easier on the clutch than than the 3.22 axle that your auto trans called for.

Doug T

The Highlands, Louisville, Ky.

paul if you do that are you going to sell the FOM?

A 6 cy T86 will give you a little advantage in 1 st gear because it has a different tooth count on the input and cluster gear, but its not much difference. I have been running OD behind Y-Blocks almost 50 years and I think the 3.89 is the ideal gear behind an OD. Years ago I put an OD in a 56 that had the 3.55 direct gears and I just didn't like the bog when I untracked it. I put a 3.89 in it as fast as I could find one. I have also had 4.11 and was pleased with them. I even have a rear end out of a 56 station wagon that is something like 4.27. I plan on using it in one of my upcoming projects. I drove the station wagon for a little while before I started cutting it for parts. After letting her slip into OD at about 60, she was ready for still more action with those gears.

Kenneth

Fredricksburg, Texas

I'm hoping John is right and I can get along OK with the 3.22.I keep thinking about the 71 pickup I had that was a 3 speed with a 3.00 gear.It was so helpless that I took back to the dealer and had them change it to a 3.50.But that truck was probably 7-800 pounds heavier and had a little taller tires than my car.

I've thought about a six cylinder transmission,but the only one I have is not OD,and I have rhe V-8 OD out of a wagon I'm scrapping,so it's free.I do have a 3.89 rear end and 3.55 and 4.27 Dana's laying here,so if the 3.22 doesn't work I can use one of them.Changing them is just a bit more more work and at my age I try to avoid that as much as possible.

Jim,yes,if I do this I'll sell my FOM.In fact I've got one laying here that I trip over every day if you need one.It's a 57, so you would have to use the tailshaft and speedometer drive gear from your 55 on it.

And,John,fortunately, I live about a 100 miles north of the Ozarks,so we don't have a lot hills to worry about.And most of my long trips are to flat central Illinois or out west where the hills are long but less steep.

Thanks for the help,guys.If and when I get this done,I'll let you all know how it works.

 

Paul,

Boonville,MO

My opinion has those 3.22 gears being on the ‘tall’ side for what you are attempting to do.  As Kenneth brings up, the factory gearing with the overdrive was 3.89:1 gears.  I’ve found you can get by with 3.50-3.56:1 gearing without straining the clutch too badly with the V8 OD tranny while having a good cruising rpm at 70-75mph but this applies to the lighter cars and not something as heavy as a station wagon.  3.22 gears with a V8 overdrive will require riding the clutch a bit longer and could potentially lug the engine down too much at the lower highway speeds.  Although you could try out the 3.22 gearing, plans should be in effect to be ready to change out the gearing.

 

Using a T-5 instead of the T-86/T-85 changes everything as the Mustang T-5 has a lower first gear and not as much percent overdrive.  In that case, the 3.22 gears would be the optimal gear.

Lorena, Texas (South of Waco)

Ted......You are likely right about the 3.22 being too tall,but I'm going to try it before changing the rear gear.

On this same subject,I know you have at least one car with OD controlled with a toggle switch.Since I don't have the wiring,relay or kickdown switch,is all I need a toggle switch to the solenoid?Is the load enough that I need to use a relay or just use heavy wire and a pretty heavy fuse in the line?

Thanks

 

Paul,

Boonville,MO

Not necessarily. Always ID the T5. Some were designed for the "weekend racers" and actually require very short, in street terms, rear gears. I think by the time I have mine all sorted out, my happy cruising speed will be found with about a 4.30 rear with the T5 I'm using.


Lawrenceville, GA

I use just a toggle switch, make sure you get one rated for 25 or 30 amps. I have a 30 amp circuit breaker wired inline .

  Dennis in Lititz PA