Columbia Overdrive Question / Information

Ken/Alabama said:
Only check and add oil to the oil plug on the Columbia housing. Don't use the one on the Banjo. There is not two different sections for oil.
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Ditto on Ken's comment...


I have driven my '36 with it's Columbia for over 94.k. The only time I ever had a problem with the unit is when a thrust washer between an axle and other components seized causing the right wheel to lock up. That was a real thrill at 60+ mph..
 
I too have driven many thousands of miles with Columbias. Only issue I ever experienced was in my 40 convertible one day and it felt like the rear of the car jumped off the ground. Got it back home and found that the pilot bearing on the rear of the pinion had came apart sending shrapnel through the rear end.
 
Ford46 said:
I have a 46-48 model year Columbia in my car which is electric/vacuum controlled, earlier years were not. Yes, depressing the clutch pedal is necessary to shift but my control is a electric switch not a manual switch as the earlier cars. In earlier cars you have to shift back to standard before stopping, in the 46-48 model the Columbia automatically returns to standard when the clutch is depressed, the earlier cars do not. I have never driven and earlier Columbia equipped vehicle, so I tried to stay generic with the testing instructions. LouB.
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Can the 46-48 Columbia be installed in a 40 so I would have that feature you describe?

Phil Swanson
 
The '42-48 rear axle assembly is approximately 2" wider than the '40 assembly. I have a '46-48 Columbia under my '36 coupe, I up graded the car from a '36 Columbia to the '46-48 unit.
There are people that will tell you that you need to shorten the axle housings and axles, this in non-sense.. The difference in the width is less than 1" on each side, not a problem.
This is all you have to do: disassemble the '40 differential, discard the axle housings, axles and rear spring. Install the '46-48 Columbia onto the '40 banjo, torque tube and radius bars, install the unit under the car, install the '46-48 rear spring, hook up brake lines and shocks. Use steel lines extending from the engine compartment to the rear end. Install '46-48 vacuum electric shift controls, making sure that you have the clutch safety switch assembly..

The whole installation is similar to the stock '40 setup, except you now have an electrically controlled OD, in lieu of a mechanically shifted unit. Additionally, the '46-48 Columbia's are much better than the earlier ones..
 
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Best advice you can have is to order the original Columbia literature from one of the peddlers. There are parts lists, installation instructions and driving instructions available which will take the guess work out of it for you.
 
[scale modeling research question]

can this unit be used with a Chevrolet rear or Ford exclusively?

Q2: only a banjo differential?

thanks
 
The Columbia will not shift unless the clutch is fully depressed. There is a vacuum control on the clutch pedal. Unless the clutch is depressed vacuum will not reach the shift cylinder.
 
I have a 37-41 Columbia in my '32 and love it. The vacuum shifting unit is a great mechanical device and I have no desire to change it to an electric solenoid.

I have a Columbia section in the Techno Source ... file below.

564672
 
Ken/Alabama said:
The Columbia regardless of year should never ever be shifted with the clutch being depressed. The early ones like on my 40 has a rod from the clutch to the switching valve mounted to the steering box. When the clutch is depressed the rod pulls a lever that opens a vent on the valve and that allows air to come into the shift can piston while vacuum is pulling it. It will stay in OD untill the operator takes it out. The Columbia can and should be shifted for the first time with the rear wheels off the ground to allow the oil to circulated through the unit and make sure it shifts correctly. The gear train is not under power if the clutch is used.
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See post 28 and 29
 
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after studying cut away & section drawings, it's a wonder they worked at all.

transmissions have replaced welding & electricity as the "black arts" to me.
 
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