columbia 2 speed rearend

Is there anyone out there who knows anything at all about Columbia 2
speed rearends?!? My boyfriend recently bought one for his 29 model A
Ford hot rod, and he’s having one hell of a time trying to get the
damn thing back together. I believe he said he is having trouble with
the differential(?).
please, someone out there, have pity on me and perhaps give me some
information I can pass along to him. Help make my life more bearable
so he can get this car out before summer is over. Thank you!

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marcine73 wrote:
> Is there anyone out there who knows anything at all about Columbia 2
> speed rearends?!? My boyfriend recently bought one for his 29 model A
> Ford hot rod, and he’s having one hell of a time trying to get the
> damn thing back together. I believe he said he is having trouble with
> the differential(?).

You probably heard him correctly -- that's the section in the middle that does
all the work. Here's an article that may help a bit.

http://www.flatheadv8.org/columbia/columbia3.htm

There's a detailed mechanic's section on this rear end in the Shop Manual for
the 1939-48 Ford. That can be purchased at various places. The section runs
about 25 pages, so it would be a bit of a pain to scan. If he has specific
questions, have him email me -- I'll look through the manual and try to find an
answer.

George Patterson
Why do men's hearts beat faster, knees get weak, throats become dry,
and they think irrationally when a woman wears leather clothing?
Because she smells like a new truck.

marcine73 wrote:
>
> The differential - the gears on the ends of the axle bind up.
> He just can’t seem to get a handle on what could be going wrong.

Ok, I'm still not quite sure what he means, but here are some things to tell him
to try. First, some background (mainly for you, 'cause he probably knows all this).

The axle is in two pieces; each ends in a gear located near the center of the
car. Those gears mesh with a central unit called a "spider." This contains four
gears in a cage. The spider bolts to a large gear called the pinion gear. The
gear on the end of the driveshaft meshes with this. The general idea is that the
driveshaft gear turns the pinion gear, and the spider rotates along with that.
Since the axle half gears are meshed with the spider gears, the axles must turn.
Since the spider gears are free to spin in either direction, one axle half can
turn slower than the other (this difference in speeds is where the differential
gets its name). This lets the car make turns. The spider is the key piece of the
differential.

Ok -- for him. Ford made these axles with gears than had different numbers of
teeth. I can't remember which years had what, but there are axles with 16 teeth
and others with 18 teeth. Axles with 16-teeth gears will not work with spider
gears intended for 18-teeth axles. If his axle was assembled from parts, it's
possible that one or more of his spider gears is the wrong part, or he may even
have two different axle halves.

There are no shims or adjustments to the spider. There are also no adjustments
possible to the pinion gear. The only adjustment available is the use of various
thicknesses of gaskets where the axle half housing joins the "banjo" (he'll know
what you mean).

Tests to run. I assume the rear end is in the car; if not, he'll be able to
duplicate these tests on the bench. Jack the car until both rear wheels are off
the ground. Put the car in gear and try to rotate one wheel. There should be a
little resistance, but it shouldn't take a weight lifter to turn it. The other
wheel should turn the other way. If one wheel will turn but the other won't, I'd
say either the bearings on that axle half are shot or that side needs thicker
gaskets between the housing and the banjo. If neither is easy to rotate, he
probably needs gaskets. Add a support under the banjo so that the rear end is
evenly supported at both ends and the middle. Drain the lubricant. Then loosen
all of the bolts holding the axle housing on the side that's binding to the
banjo. Loosen them about 1/16". If that axle rotates now, he needs thicker gaskets.

If neither wheel will turn without a great deal of effort, he definitely has a
problem with the spider binding. Add a support under the banjo so that the rear
end is evenly supported at both ends and the middle. Drain the lubricant. Then
loosen all of the bolts holding the both axle housings to the banjo. Loosen them
about 1/16". If the axles rotate now, he needs thicker gaskets.

If he still has a problem there, the rear end will have to come apart. We can
discuss that later if necessary.

I will not be able to help troubleshoot the actual overdrive beyond looking in
the manual (and it doesn't say much). I will say that, if he thinks he has a
problem with it and the overdrive unit has been drained of lubricant, it can
only be filled by running the car. The lubricant should also only be topped off
using the port on the overdrive unit; not the usual one on the banjo.

George Patterson
Why do men's hearts beat faster, knees get weak, throats become dry,
and they think irrationally when a woman wears leather clothing?
Because she smells like a new truck.

marcine73 wrote:
>
> He just can’t seem to get a handle on what could be going wrong.

One other thing that just occurred to me. If someone reversed the axles such
that the pinion gear is on the wrong side, something will definitely bind. I
can't remember if you can actually assemble the entire rear end this way -- I
think you can. But then nothing will turn.

George Patterson
Why do men's hearts beat faster, knees get weak, throats become dry,
and they think irrationally when a woman wears leather clothing?
Because she smells like a new truck.