Mitchell O.D. in a 1937 Ford?

groundloop

Junior Member
Hello, I have a 1937 Phaeton I want to make more roadable.
Not wishing to debate all of the other overdrive alternatives, I was wondering if anyone has some experience with the Mitchell O.D. or installing one in a 1937?
I have heard rear floor modifications may be necessary on some models. Any experience you can share would be appreciated.
 
Rear floor mod, yes. Closed car Mitchell (straight cut gears) noise competes with the sweet song of the engine, not sure if that noise is as loud with an open car.
 
Not sure what noise PP is reffering to as I have one from 2023 in my 41 and don't hear it at all. As for the install and operation of it, after several thousand miles we are thrilled with it. It works smooth with the cable shift. I set it up to look like the 49 style OD T handle undre the dash board. The install took me four days as I removed the rear spring pack and axle for cleaning , puting in spring liners , shakle bushings and painting. Just following the simple instructions made it a snap. Tim
 
Not sure what noise PP is reffering to as I have one from 2023 in my 41 and don't hear it at all. As for the install and operation of it, after several thousand miles we are thrilled with it. It works smooth with the cable shift. I set it up to look like the 49 style OD T handle undre the dash board. The install took me four days as I removed the rear spring pack and axle for cleaning , puting in spring liners , shakle bushings and painting. Just following the simple instructions made it a snap. Tim
What rear end ratio do you have? I would consider doing the same. I have 3.78's.
 
Not a 37’, we have a 39’ Tudor Sedan.
It has 4:11 gears.
Was going to order highway gears.
Friend called, he was taking the 39’ 3 speed & Mitchell OD out of his 39’ Coupe.
This was during Covid.

I called Mitchell and talked to the Son. Believe Dad passed on.
He was very informative and helpful.
Told me if I have 4:11, you want his 36% OD.
If you have 3:78, you want his 26% OD.

He had units on the shelf with not all the complete parts to ship out due to Covid.
It was 36% to match our application.
He advised me to buy it. And we did.
Fit like a glove.
Cable operated.
No whine.

So, we live at the foot of the Adirondack Mountains.
So the 4:11 is nice for hill pulls.
And the OD is great to have on the Flats.
 
I believe it would be helpful if you informed us of whether you modified your floor and/or had any interference problems with the Mitchell.
 
i have one in my 37 4dr and it fit fine and is quiet.i did have to create a small dimple where the shift lever hit the floor pan, no big deal. i have driven the car around 40,000 miles with the Mitchell and my Ron Holleran built engine, good oil pressure and burns no oil. i have the 28% with 3.78 gears. highly recommend the Mitchell ! drove back and forth to Syracuse Ny 700 mi round trip and makes driving the freeways a pleasure.
 
Rear floor mod, yes. Closed car Mitchell (straight cut gears) noise competes with the sweet song of the engine, not sure if that noise is as loud with an open car.

Mitchell OD's use helical gears with synchronizers for smooth and quiet shifting.
 
Not a 37’, we have a 39’ Tudor Sedan.
It has 4:11 gears.
Was going to order highway gears.
Friend called, he was taking the 39’ 3 speed & Mitchell OD out of his 39’ Coupe.
This was during Covid.

I called Mitchell and talked to the Son. Believe Dad passed on.
He was very informative and helpful.
Told me if I have 4:11, you want his 36% OD.
If you have 3:78, you want his 26% OD.

He had units on the shelf with not all the complete parts to ship out due to Covid.
It was 36% to match our application.
He advised me to buy it. And we did.
Fit like a glove.
Cable operated.
No whine.

So, we live at the foot of the Adirondack Mountains.
So the 4:11 is nice for hill pulls.
And the OD is great to have on the Flats.
Good to know about the ratio changes available.
 
Thanks everyone, this has been very helpful, I welcome any additional experience on the subject! What is the best way of determining the gear ratio on a 1937 for the Newbe? My car is comfie at about 50 55 mph.
 
Gear ratio is embossed on the rear end housin. Actually on the built in stiffiner.

Attached is a picture of a 1937 rear axle housing showing the location of the stiffener Lawson mentioned above. For the 3.78:1 ratio it will show the numbers 9 and 34, 34/9=3.778.
 

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Ground Loop.

1) Your 37’ is 88 years old. No telling what has been done to it over the years.
I would not rely on Housing Stamping to achieve gear ratio.
Drain the Oil.
Remove fill plug.
Spray some Brake Clean on the Ring gear.
Let it dry.
Take a long skinny modeling brush , and apply some white paint to one gear tooth.
Let it dry over night.
Next morning, rotate and count ring gear teeth.

2) We have a 39’
You have a 37’.
I believe the floor boards are the same.
But I suggest you cal, Mitchell, and talk to Son Steve.
 
Well, comments halted 24 hrs ago after my last comment after thread was rolling right along.
Did i screw up ?
 
Absolutely NO screw up on your part. and thank I everyone for their valuable input. I do ultimately plan on calling Steve. I subscribe to the old "Ask the man who owns one" method of learning about a product before letting a salesman in. It also allows others to learn as silent partner's as I normally do. I also notice there isn't a lot of Mitchell OD buzz out there, 99% positive, short of alternative OD device preferences, but minimal tech talk.
Assuming I counted my teeth on my ring gear, How dose that translate to the gear ratio I have?
 
Well, I went back thru the posts, and several post tell the formula for the rear end ratio, but don't see any numbers from you! What again is the tooth count?
 
I haven't counted them yet. It was suggested That I count the teeth incase the gears have been changed at some point in it's life. So, my question was "Assuming" I counted the teeth on my gear, How does that translate to the gear ratio I have?
These could be important related details for myself and anyone who wants to learn how to cypher unknown gear ratios.
 
So, my question was "Assuming" I counted the teeth on my gear, How does that translate to the gear ratio I have?
.

divide the ring gear number by the pinion number. You can't count the pinion number, but tell us what the ring gear count is and some one will give you the ratio.
 
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