Mitchell Overdrive

F

frank d kirkstad

Member
Hi folks.
I have a 36 coupe with stock running gear and a 4:11 rear.I'm not comfortable driving more than 40 mph, because of the excessive rpm.I have no plans on running any major highways, but it would be nice to keep up with traffic on some of the local roads and not have to pull out of the way because of tailgaters.I remember seeing a Mitchell with cable shift many years ago on a 36, but an opening to allow room for the unit had to be cut in the floor in front of the differential. A cover was then fabricated to cover it. Has anyone installed one, and is this still the case or have the newer units been improved on?
Thank's
Frank
 
Perhaps it has a 6 blade truck fan----- 60 shouldn't be a problem, I ran the 39 with the 60hp and 4:44 rear over 65 all the time
 
Thank's Kurt.
I'm using a 4 blade stock fan. At about 45, I'm only at less than half throttle with plenty to spare. I'll try and hook up a tach. to see what my rpms really are.
Thank's
Frank
 
Frank, have fitted a Mitchell overdrive to a standard 36 coupe and did have to modify the rear floor a little and make a little cover for the cut out section. That was about 4 years ago. Regards, Kevin..
 
Another option you might consider is a higher ratio rear end, e.g., 3.78. Mitchells are nice, though.
 
Maybe a Mitchell and a 3.78 rear. Best to my knowledge you will have to mod the floor on your setup. Have a 36% mitchell on a 38 (thinking about it on a 36 coupe) a healthy flathead (3.78 rear). love it. 36% a bit much but I pull it okay without headwind. No need to open drive it or get rid of the tube design.
.
 
On my Mitchell I only moved the cable shift arm downward instead of up but it make the cable pull to disengage and push to engage.Love the Mitchell.Mounted the cable to the left of steering column.Wold not have the floor shif and didn't have to modify floor on my 40
 
I had to modify the floor in my '47, it cleared in the garage but it would hit on bumps going down the road. It didn't take much to clearance it, but a '36 would probably need more.
 
I have an overdrive in my '47 convertible. It is a 30% reduction when engaged. The car has a 3:78 rear, and if you choose a unit with that ration, it should do fine with the 4:11. It will allow you to leave it in overdrive a lower speeds. My Ryan unit mounts directly to the rear axle banjo, and I shift it with a cable sold for truck power takeoff application with the knob under the lower edge of the dashboard. I can run at highway speeds above 60 mph. Just be sure that your brakes and steering are in top shape for such high speeds.
 
here is my floor conversion for my mitchell.
 
That is why I moved the shift brkt to the bottom when someone was in the back seat it would hit on a bump.Changed the shift lever in OD unit and no more bump.Did't have to modify floor at all.Went with 36% with 378 gear
 
Here's what I had to do with my '47, a small notch on either side of the driveshaft tunnel. I used an old 289 valve cover and welded it in on both side.
 

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Thank's guys for all the response and suggestions. Changing ratio is an option, but setting up a new ring and pinion requires a lot of work, with adding and removing shims to get the mesh just right and also there's the question of the quality of the new gears.We all know about reproduction parts! A mitchell seems the way to go, since it appears to be a bolt on item, I just have to convince myself to cut a hole in the floor.
Frank
 
Frank, just fit up the overdrive unit and then see how close it is to the floor. Cars vary so you might not have to modify the floor much. As others have said you wont need to touch the rear end, your 4.11 will be good to go. Regards, Kevin.
 
Go with a Columbia and avoid having to butcher up your car. Columbia set ups were made and engineered for Fords.
 
Frank cutting a hole is the last thing I 'd worry about It would be the big smile on my
face If I could afford a Mitchell. The thing embedded in my mind still in high school
summer job picken weeds painting windows for a retired whisky pickled soft hatted gent
would send me to the dump in his car a 49 V8 business coupe with OD what a dream
to drive a whisper quiet car. Go for it sam
 
jimTN said:
Go with a Columbia and avoid having to butcher up your car. Columbia set ups were made and engineered for Fords.
Click to expand...

True : but try and find one yeh ebay and then you need a student loan and
thats with no guarantee's either. Not to mention shipping. Other than that
you are correct.
 
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