Anybody ever use a mitchell overdrive?

I'm thinking of one for my '47 Ford. I've heard they can be a little noisy, I've heard they misadvertise they're gear ratios, i've heard some even had to modify their floor, but it's still an overdrive. Anyone have any first hand experience?

 

Where do you get one? How much?

 

mitchell manufacturing makes them. They take the place of the torque tube. It's still a closed drive torque tube, but with a gear reduction box mounted on back that you can engage and disengage. Price is a hair over $2k. Wait is about two months. Look on the fordbarn and I'm sure you'll find more info. I was wondering if any hambers used it before though.

 

Sounds like the one whiskeyrunner is running on his 37 rat truck.
pm Chevygirlrox for info. He likes it but had some problems with the flathead overheating when it kicked into high gear on the highway.

 

Not sure if it was a Mitchell, but we used some of the in-driveshaft overdrives in our Great Race "A" speedsters. Ours were great, 85 mph in a stripped down but stock motored Model A. I'd get another one.

 

Well, I am very familiar with them and have installed more than one --and you are the first one that I have ever heard say they mis-advertise their gear ratios. Unless I am mistaken, you can get a 27% and a 33% O/D ratio.

I would say that there would be occasions where you would need to modify a floor to have clearance, yet I have never even heard the noise from one but maybe that is because of the normal engine & transmission noise. The insides are very simple, ...and in underpowered cars being "toured" in the mountains, the ability to split-shift is a nice feature. After they are 'worn in' a bit, you can shift them on-the-fly without even depressing the clutch pedal, just lift and flip it in and out of O/D as need be. If I had to give a negative, I would say that the extra gear shift lever protruding from the floor can be a nuisance --especially in cars that have tight floor spaces. Other than that, they are a quality piece in my mind.

I am intrigued why you would be compelled to install one in a 47 though. The price is actually a bit more than $2K --plus the freight. I would think you would want to go with a 'more modern' transmission that would have an O/D built in and synchro's to boot. The costs would be much less.

 

does it look like this. if so, My dad had one in his 40 coupe. I loved driving it, no noise.. would allow flattie to drive at 75 with no problem..

 

It's expensive, but looks to be WAY less trouble than adapting a late OD to torque tube and superior to cobbling up a split rods/open drive setup on a Ford. Apparently they are sold already installed in a replica tube.

 

for 2 grand you couldnt you just by a early 50s ford overdrive and convert the stock rear to open drive with the yoke peice off a truck rear?

lol haddnt considered the whole wishbone suspension stuff that bruce just brought up. lol never mind.

all hail bruce lancaster once again lol

though with the new "trans" gearing wont you have to swap out your rear gears anyways?

could just through in a 5 speed, an open rear with the right gears, and put a torque arm on the suspension to take care of the missing torque tube?

thought i guess when it comes down to it that 2 grand box might be cheaper

just thoughing ideas out there.

tim

 

In the case of my dad's, it was the original torque tube. He took the set up to a place in Sacramento and they did the work. no clearance issues, no floor adjust, at least not on his 40

 

Stud - I'm going on three years running a Mitchell in my rascally Merc-powered '37 Slant. It is by far the best thing I ever did to it. Been clocked at 111 mph. Not everyday, mind you, but it's nice to know it'll get out of everbody's way when you have to. It'll shift at any speed and I find myself driving it like a 4 speed most of the time. I hum-haw'd about the 36% vs 26% and decided to go with the 36%. Glad I did. There's been some talk about mis-advertising ratios and loud noise. I've never done the math, I just drive it. Maybe I'm lucky, but mine is virtually silent. I opted for the floorshift and built a little console around it and topped it off with another '39 top cover. It looks like it grew there at the factory. It's a blast to drive and now I can actually leave town. And, if you get really bored sometime, it'll do 55 mph in reverse!

 

Some stuff: Several people (and one commercial outfit) have adapted toploader Fords to torque tube. One variant of this trans is OD. One of my friends is hacking away at this idea. On T-5's and such, I suspect 4 WD versions would be easiest to adapt.
Another tube mount OD is available from Gear vendors:
http://www.gearvendors.com/custom.html

I've never heard of anyone trying this one, and I suspect it costs even more than Mitchell.
Lincoln torque-tube trans are expensive as hell and are not noticeably friendly with Ford chassis--some seriously inconvenient protruding bits. Likely easiest to fit in an A, with an open area in the middle. Close ratio Lincoln gears, OD, and 4.11 or 4.44 rear might be real nice.

 

I drove a great race model a coupe with it and it was awesome. I don't recall any particular gear whine.

 

Thanks for all the info guys! To answer why in a '47? I like the column shift and I like that it bolts in. I think I could easily spend just as much adapting something else, one thing leads to another, I don't really want to go parallel leafs, open drive, ect.... and it would end up costing just as much. I might consider a 4:11 ring and pinion if I do it.

 

I have an OD conversion that is in the torque tube and uses a Volvo (?) OD unit.

I'll try to remember to take pics of it and post'em here.

I never used it. It came in the trunk of a '40 coupe I bought outa' Calfornia about 15 years ago.

 

i have some kind of overdrive adapted into the torque tube of my roadster. its old and crude looking but it works pretty good and makes 100mph possible without alot of effort
a friend of mine just put a mitchel in his 31 roadster but its not on the road yet so i dont have any input from him.
i think I'd engine turn it all before you install it though just to make it look a bit more old timey

dont go open driveline if you dont have to. as im sure you know already, nothing beats the look and simplicity of a stock ford banjo set-up

good luck
Zach

 

Have any more info on this? Is it a home brew? Wanna sell it?

I do have a '49-51 merc overdrive tranny, but it's open drive and a little more complicated. By the time I make it work I'd probably spend just as much.

 

I put one in my '32 and I would say it was the best thing I ever did to help drivability. Mine was not noisy and shifted great. Clearance with the floor might be a problem on some cars especially if they have been lowered.

 

The volvo OD and another conversion using a BW OD of the sort common in the 1950's used to be done commercially for Model A's. Don't know if they still are, and donor parts for both are probably getting pretty scarce.

 

The Gear Vendors rig is utterly bulletproof and serious overkill for any flat motored car. Plus it's way dearer than a Mitchell--maybe close to twice as much. The toploader OD trans referred to is the T170 which only came in a few years of 80s Ford trucks but is an excellent choice that can be adapted to a torque tube. A guy in Dallas does the conversion and it sells for around 2500 bucks last time I checked It involves considerable machining. Even at $2K a Mitchell is hard to beat when the costs and hassles of other setups are all taken into account plus its flexibility is second to none.

 

A load of guys on Ahooga run converted Volvo OD units grafted into their torque tubes. The OD is actually a Laycock J-type unit and I think it works out to around half the price of the Mitchell.

 

What's the story on the volvo units? Are they still being made?

 

saw your setup out on the salt this year very nice

 

Also, a '47 Ford in good shape is a great handling and riding car. It would be a shame to cobble the suspension with truck springs or split rods. It just needs more gears, and here they are!
Hmmm...4.44 gears and 33%...have your cake and eat it too!

 

They were made by Laycock, and I understand Gear Vendors bought all the Laycock hardware.

 

My Edsel is 3spd manual w overdrive.
Rear end is 1:3.70 and overdrive reduces that to about 1:2.60 !!
Accelerates nicely and pretty low rpm`S when rolling 60 mph !

But, now I`m dreaming about 3 speed auto trans with overdrive !
Ain`t easy to put that manual overdrive unit to cruise-o-matic ?

 

Gear Vendors is licensed to produce the Laycock style OD's by: Laycock de Normanville, a European mfg. They did not give up any patent rights or designs. An excellent OD that I've been familiar with for over 50 years. Even the little Mdl J will take a beating. Every thing from a MGB up to a V8, within reason. That's where Gear Vendors take over. They will handle, with their standard unit, hp up to, I believe 800 to 1000 hp. One should actually go to their site to confirm the hp and torque that their units will handle. They are heavy duty though. One just needs to pay to play.

 

contact Rodger Anderson at www.model-a-autoparts.co.nz for details on New Zealand made overdrive

 

I have one in my 31 coupe. It came with it already installed when I bought it. works good. I always wondered why they couldn't have used an actuator or solenoid with a switch instead of the extra shifter

 

Here are a couple of pictures of a Gear Vendors O/D being mocked up in my 32 frame. It's adapted to a Ford/Jeep toploader 4 speed.