Columbia vs Mitchell overdrive

[blucar]

I had a '73 GMC 5500 series in my business for many years, it was a 400 CID V8 w/Clark 5 spd and an Eaton 2 spd rear end. The truck was rated to carry 18K on the rear axle, with a GVW of 30K

The GMC had very similar shift controls as the Columbia under my Ford, only difference was there was no vacuum, everything was electric with solenoids and a small electric servo motor mounted on the axle housing and a control switch mounted to the gear shift stick.
The ratio of the odometer was controlled by a Steward-Warner unit that was very similar to the SW switch in my Columbia control system.
The truck was generally driven as a ten speed, split shifting each gear with the two speed rear axle.
I did the same thing with my '36 when I was street racing.
As a side-bar: During 1954-56 I had a friend that had a '36 5 win coupe that was a Standard car, a real Plain Jane, Dicks car weighed under 2,900 lbs., when we weighed our two cars. The only modifications Dick had done to his coupe was a stock 24 stud engine, hydraulic brakes, 650x16 rear tires and 5 on 5.5 wheels w/47-48 hub caps.

[Ray in La Mesa]

Had a 46-48 in my '28 A roadster pickup since 1974 and just turned over 87,000 miles on it, I love it. Have a Mitchell in my '30 A cabriolet also.

[Jim Hamilton]

I’m starting to feel the same way Glenn, I’ll probably call John and get this started.

[Jim Hamilton]

Originally Posted by glennpm

I have a Columbia in my 32 roadster and love it. I use it all the time 35-40MPH and up. It is a pleasure and in my opinion, period correct. I don't like modifying the frame or torque tube etc.

Glenn

Originally Posted by Ray in La Mesa

Had a 46-48 in my '28 A roadster pickup since 1974 and just turned over 87,000 miles on it, I love it. Have a Mitchell in my '30 A cabriolet also.

How hard have you guys treated yours and are they modified or stock Columbias?

[glennpm]

Hi Jim,

I have bought the services and parts to fix and strengthen my Columbia. I did the assembly myself with help from my V8 club friends of yore. I don't beat on it nor due I baby it. I do take my time shifting into and out of OD though.

I'll provide more input later today.

Glenn

[glennpm]

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I bought parts from Dan Krehbiel and John Deets. I bought new bearings, bronze shims, gaskets, basically everything that I could get new. In recent years I've bought the synchro clutch rebuild kit, vacuum canister shaft and some gaskets from John Connelly.

I had the A-24 differential case banded, A-30 differential cross tees shortened and the A-17 basket weld reinforced by John Deets whose work was excellent. I had a good crack free A-24 to start with. A couple of years ago I rebuilt my clutch with a kit from Connelly. See the attached especially pages 7 and 8.

Assembling the unit wasn't hard. The tedious part was lifting the heavy assembled housing to properly shim the unit.

Search here for other rebuilders. Dan Krehbiel has good reports here and there is someone else in GA I believe that's been recommended. Search here. Connelley isn't the only good vendor to pick from.

[Jim Hamilton]

Glenn,
Thanks for that article, I really enjoyed that!

[glennpm]

Yes, it is very good

[Ray in La Mesa]

I had John Deats of Long Beach, Ca. rebuild & bullet proof my Columbia in h the 70's. I have used it for normal service and a few times hauled loads of 1500 lbs in the pickup, gingerly of course.

[Kens 36]

Originally Posted by glennpm

Search here for other rebuilders. Dan Krehbiel has good reports here and there is someone else in GA I believe that's been recommended. Search here. Connelley isn't the only good vendor to pick from.

Please be aware that Dan Krehbiel passed away in May. A great loss to our hobby.

Ken

[glennpm]

Yes, too bad about Dan. He was a great guy to talk withy and great with Columbias

Re: Columbia ...Tenn. guy
Johnny J. Stooksbury
1116 Wallace Rd
Knoxville, TN 37919-8452
(865) 690-7585

[Kube]

I too am in the Columbia camp. I have NEVER had an issue with any of them. Of course, each is properly rebuilt and installed, and they are shifted per the directions.
John Connely has been a great source of parts and service.
He has modified housings for me a number of times and each has been perfect.
Good man, good machinist... you can't go wrong with John.

[Joe KCMO]

Don’t wait to get this specialty work done by these wonderfully skilled vendors. Each year there are fewer! I recently had a Columbia bullet proofed by John Connelly. Had everything and knew how to do it also. I wonderful person to do the hobby.

[Jet96]

That article is quite helpful.

[Jim Hamilton]

I finally got my order in to John at Columbia Two Speed, ordered it in April with 2 or 3 ahead of me and as of Friday June 30th, he’s already boxing everything up.
I had more issues keeping me at work a lot and more things to fix at home that prevented me from getting all the research done and getting my order in.
Many thanks to you guys for your help!!

[Jim Hamilton]

Another thought/question do any of you Columbia guys get spare parts for these? I’m thinking of getting a spare steel A-24 and another A-17. These look to be the first to let go if my right and left feet work too hard together at a spirited take off!

[ssffnomad]

Our 39’ Tudor Sedan has 4:11 gears .
Few years ago, was able to purchase a hardly used Mitchell 37% OD.
Easy to install.
Works like a charm 👍
Stretch

[95476]

I have a Columbia in my '34 3-W coupe and a Mitchell in my '34 P/U. I like both of them but think the Mitchell might be the stronger unit. I don't abuse either of them soitis not an issue for me.

[Jim Hamilton]

I was thinking a lot between the Mitchell and Columbia. On my ‘46 it was going to require some floor and torque tube work. My goal for this car is to be a ‘50s mild Hot Rod without any cutting. I do though want to get another hood to be louvered.