Columbia Rearend Questions

My brother is looking at a Columbia rear end out of a 41 Ford car.

We have never been around Columbias, so we have a few questions.

What is involved with shifting one. The rear has a vacuum? pot, what other pieces do we need to look for?

Can these be shifted mechanically if all of the parts are not there?

Typically what percent overdrive were these?

Do they use standard Ford axles, ring and pinion, etc?

Any input would be appreciated.

Thanks,

Neal

 

I just sold a 40 that had a vacuum switch under the dash. Don't think they used electric on them. I didn't have the speedometer changer, it changes the gearing of your speedo when the rear changes ratio. I have one from a 46 in my 37 p/u and it works by electric over vacuum. Solenoids govern the direction of the vacuum to pull it from one gear to another. A switch controled by the clutch pedal and under dash kicks it in and out. They use standard axles and ring and pinion and a sun gear in the overdrive. I think mine has a 354 on the low side and about a 278 on high side.

 

I read that hot rodderes use a Ford truck 12v gas tank selector valve to route the vacuum. The vacuum is routed to one side of the vacuum canister to engage the O.D. When the switch is thrown the vacuum is redirected to the other side of the canister to disingage the O.D. Of course that won't change the speedometer gearing.

The original controls are very pricey if you can find them. Check in Hemmings for the guys in Tenn.. They bullet proof the rears and have lots of info on the different systems for the different years. I think they have a vacuum diagram for the Ford valve but you can probably figure it out.

 

Thanks for the info, guys.

The rearend would be going into a hot rod, so the fuel tank valve sounds like the way to go.

My brother is second in line to buy it, so hopefully the other guy flakes.

Thanks again,

Neal