Does Mitchell Overdrive From 29CP Fit a 31CP

Nasukau

Nasukau

Senior Member
Hi All,
I recently bought a complete running gear minus the frame out of an 1929 Coupe and the rearend has a Mitchell overdrive. I want to install the overdrive in my 1931 Coupe. Will this unit fit the way it is or is there a difference in driveshaft lengths of where the actual Mitchell unit sits underneath the vehicle from year to year for the Coupe’s since there is two separate pieces of driveshaft?
 
You’ll need a different speedometer cable extension, the u-joint housing may also be different, I’am not sure about a difference in the shifter
 
I understand that the length of the total driveshaft is the same. I am referring to the clearance of the metal gear box underneath the body of the car. I have never owned a 29 coupe so I just wanted to make sure that the metal box can sit in the same place under my 31 coupe body.
 
It should be a direct fit, neither body pans drop below the frame rails. Only the Victorias & possibly fordors with the dropped rear floor pan are different.
 
Talk to Steve at Mitchell, why guess at it. I would say that they make one that fits if it does require one (or if you already have one, the parts to convert it) (I would bet $1 it’s a direct bolt in)
 
It will fit. You will have to get the Speedo cable extension for a Round speedo. I'm sure Mitchell Mfn can supply that.
 
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Different question along the same lines. Can I put an Extension onto my speedo cable just so I have a little more 'slack' in routing the cable? this is on a '29 Tudor
 
The speedometer cable must be driven by the Mitchell OD unit to correct for the ratio change in it. This is why it needs the extension. It is relatively long and any extra length would have to be coiled in a way that would still allow the inner core to rotate freely. Most model As have a length that is suited for the model year applicable. I've not seen one that didn't fit if properly routed.
 
Canton_Model_A's said:
Different question along the same lines. Can I put an Extension onto my speedo cable just so I have a little more 'slack' in routing the cable? this is on a '29 Tudor
Click to expand...

You could have a custom speedo cable made if you really need a longer one.

I had to have a custom cable made for my '55 Ranchwagon to connect my C-4 trans to a ratio adaptor so my 160 mph speedo out of a '55 T-Bird would read correctly.
 
Nasukau said:
Hi All,
I recently bought a complete running gear minus the frame out of an 1929 Coupe and the rearend has a Mitchell overdrive. I want to install the overdrive in my 1931 Coupe. Will this unit fit the way it is or is there a difference in driveshaft lengths of where the actual Mitchell unit sits underneath the vehicle from year to year for the Coupe’s since there is two separate pieces of driveshaft?
Click to expand...

To answer your question directly, yes. In fact, you could just swap the entire rear end if you really wanted to.

What you will find different is the speedometer drive for a 31 vs. 29. The 31 is a square end drive, the 29 has the flat end.

The other issue is the shifter mount bracket that holds the Mitchell shift lever. If you have an early 29 with the emergency brake in front of the shift lever, you will have a different bracket than the 31 uses.

Steve Mitchell can hook you up with the correct shifter mount bracket and speedometer drive cable. He is recovering from hip surgery at this moment (but doing very well!), so you may not get an immediate response.
 
Call Steve & Cindie Mitchell for the things you will need.

800-859-2088
530-458-4500

They are in Colusa, CA

Tom Endy
 
I called him on Monday and left a message. Within an hour he responded. I have a regular Mitchell OD in a box waiting for another A that needed an OD. I was looking at a Vickie and he said that I would need to convert both the input and output shaft and outside tube to avoid the OD hitting the floor pan. There would be a cost for the parts but not too much. Return on the unused parts. I could do the work myself. No 8 month wait for the parts. He needs a few more people working there.


Vic
 
I don't remember but I think the Mitchell takes a different cable end fitting than the Model A. If it is the same as a Model A, the AA's have longer cables.
 
I spoke to Steve Mitchell and he said everything should fit except the speedo cable and gear. I ordered the correct speedo cable and gear from him. Thank you everyone.
 
Glad to hear Steve’s hip surgery went well. Thanks for passing that along, Paul.

He and Cindy are truly dear people, the hobby is well served to have them in it.
 
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