Columbia 2-spd Shift Fork

[solidaxle]

Is it possible to install the shift fork backwards? Reason I question it, the sliding rod controlled by the vacuum pod misaligns with the end of the shifting fork occasionally when it goes into high. This has happened twice in the last year and I have to remove the vacuum pod and realign it. Looking at the PDF parts diagram from Columbia, I don't think it's possible.
The PDF parts diagram "seems" to show a nub on the fork facing away from the banjo center, mine faces the other way as shown in the first picture.


My other concern is the end of the shift rod on mine has a pointed top as shown in the picture, seems like that should be down touching the sliding rod. The last picture from John Connelley's web site shows the proper way to have the rod and mine is correct as the picture.
So before I go pulling it apart, I would like someones opinion.

 

[Ken/Alabama]

It’s not possible. The fork has a “cam” for a lack of a better word that would be upside down.

 

[Brian]

I have two Columbia's semi-stripped at present. The fork in the '39 unit has that angled nub facing the other way, and a straight nub on other side. In Ken's photo, I can't see an angled nub, just a straight nub, which is opposite the angled nub in a 39 unit. Interestingly, in the '36 Columbia I have in bits, there is no angled nub, only the straight one.

 

[Ken/Alabama]

I have two Columbia's semi-stripped at present. The fork in the '39 unit has that angled nub facing the other way, and a straight nub on other side. In Ken's photo, I can't see an angled nub, just a straight nub, which is opposite the angled nub in a 39 unit. Interestingly, in the '36 Columbia I have in bits, there are no nibs/protrusions either side of the fork!!

****, I’ve got at least half a dozen of them. They’re all the same. I see no way to put it in upside down. Maybe we’re taking about two different things.

 

[Brian]

You are correct ken...I'm trying to add a coupla pix....

 

[Brian]

39 Columbia arrangement

 

[glennpm]

From my 40 Columbia

 

[TerryOH]

There may be a problem with your vacuum canister assembly A49 allowing it's shift rod to move or there could be loose or missing parts in the columbia axle housing. I would remove the axle housing A1 and inspect.

 

[glennpm]

I'd try operating the lever by hand before I pulled the housing. It should not be loose and only click in and out as the vacuum cylinder action does.

 

[solidaxle]

I should have added, my Columbia is a 1942-48 style if that matters. I didn't think you could install it wrong, but couldn't really tell from the cut away diagram or looking inside the unit through the vacuum pod opening.



To embellish more on the problem. It works fine when I have everything lined up and reassembled. Eventually, the 2-sdp would start to take longer to shift into high sometimes as much as three attempts, once in high it has no trouble going into low, as soon as the clutch is disengaged, it shifts. My first thoughts were there's something wrong with the vacuum valve, I checked all the hose and clamps all looked good, so I switched hoses on the pod. Now the controls are opposite, but the results were the same, no high. There's also plenty of MM oil on both sides of the leather seal plunger.
When I removed the vacuum pod and housing the last time.There was resistance on the sliding plunger when the fork is in the high position, towards the wheel, like it's going to far and jamming. The seal for the rod feels right, no slop and good seal. Is possible the rod has too much travel?

 

[solidaxle]

I'd try operating the lever by hand before I pulled the housing. It should not be loose and only click in and out as the vacuum cylinder action does.

Operates fine by hand.

 

[solidaxle]

One other item. I pulling 20 on the vacuum gauge when I let up on the gas. It shifts into low quickly when I push in the clutch, almost too quick, like there's too much vacuum.

 

[Ken/Alabama]

Did you put a new rubber seal kit in the vacuum valve ??

 

[solidaxle]

Did you put a new rubber seal kit in the vacuum valve ??

Are you referring to the vacuum pod on the rear housing? Yes it has been replaced and it seals well.


The controls are 37-41 type and that received a new seal,ball and spring also.



Vacuum is not my problem.


What stops the fork lever from going too far?

 

[Ken/Alabama]

Are you referring to the vacuum pod on the rear housing? Yes it has been replaced and it seals well.


The controls are 37-41 type and that received a new seal,ball and spring also.



Vacuum is not my problem.


What stops the fork lever from going too far?

Ok. When you said your Columbia was a 42-48 I assumed the controls were also.

 

[glennpm]

Is the shaft a new one from John Connelly? The shafts he supplies are a bit large on the diameter. John told me this


Columbia Two Speed Parts <columbiatwospeed@earthlink.net>
Oct 27, 2014, 11:33 AM
to me

Glenn,
sand it down to .624 +.0 -.001

 

[solidaxle]

Is the shaft a new one from John Connelly? The shafts he supplies are a bit large on the diameter. John told me this


Columbia Two Speed Parts <columbiatwospeed@earthlink.net>
Oct 27, 2014, 11:33 AM
to me

Glenn,
sand it down to .624 +.0 -.001

I went over the rebuild parts list and don't see a new shaft.


When I get a chance, I'll pull the vacuum actuator off again and see where the fork naturally stops when in high gear. Then push on it by hand to see if it will go further in the outbound direction. There must be a stop or something limiting the travel, maybe that's what the nubs do.



These old cars are fun.

 

[glennpm]

That they can be

 

[TerryOH]

Not a too much vacuum issue. 20 is great. Moving the piston in the vacuum can by hand is a hard thing to do. Although lubing the piston seals and soaking them with MMO is great you don't want a puddle of MMO in the can on eather side of the piston. a coating is fine.
When the Columbia shifts vacuum is put on one side and the other side is vented through the valve. Make sure the vent is open and the linkage adjusted properly.

 

[solidaxle]

Update:
Columbia has been shifting fine into high with nothing done to it except reassemble. But I can't leave well enough alone, so I pulled the actuator again. Wanting to have another look-see on what maybe going on with the high shifting. My suspicion of the fork over extending was found to be unwarranted. As you can see by the picture, the nub on the wheel side doesn't do anything. There is nothing to come in contact with to stop the fork from over extending and jamming up in the rod slot. Moving the handle by hand from low to high it stops at the position where the rear is fully engaged and will not go any further. So I reassembled everything again and will drive it around and see how it goes.

I did notice the clutch adjustment was at it's minimum of an 1/8" push down on the control valve. A couple of turns on the adjustment rod got me to 1/8" to a 1/4" with the clutch pedal to the floor board.