VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 1940 Vacuum Shift Unit

Can someone tell me to procedure to eliminate the vacuum assist unit and go straight manual shifting ?

Is there a conversion kit or do you just plug the vacuum line to the unit ?

Thanks,

Wes Marquis

There is a kit...Lots on E-Bay...Fix your vacuum assist unit..and don't replace it,you will be sorry

Chef-chevy, thanks for the reply, What is the down side of removing the vacuum assist ?, most of the cars I see at shows do not have the vacuum shift. There dosen't seem to be a lot of people who know much about maintaining or repairing of the vacuum assist unit.

Wes

There has been several discussions on vacuum assist gears on Chatter lately.
I doubt you will be happy without a properly adjusted assist.
Tony

What is specific problem with your Vac assist unit???I've tried the by-pass unit and there is a big negative difference in the smoothness of the shifting...I feel it is the difficulty of the linkage adjustment that is usually the problem and not the vacuum assist...Check for air leaks in the unit and seal them if thats the case,don't by-pass it,once again you will not be happy

Chef-Chevy, I'm sending you an E-Mail, here is the problem I'm having:
1. When I pull up to a stop light in 3rd gear, I have to get the car rolling in order to shift to 1st. To get around this I shift to neutral as I'm rolling to a stop and then shift to 1 st.

2. I have to double clutch to shift to 2nd from 1st.

3. Sometimes going down steep hills in 3rd it will jump out of gear.

My belief is the unit needs Lubrication and Adjustment, I'm just a little gun shy as I don't know anyone with the experience of doing this, I find the write up in the shop manual a little complicated.

Wes

mine did it similar to what you saying. i got it on the rack and pulled the hose loose then back on to watch what happens to the vac unit. what i found was a bad hose. once i replaced the hose and shot a little WD on the shaft and in the vac unit, it worked ok.. hopefully yours will be easy to fix. kw

Ken,
Thanks for the info, I can try that, my vacuum runs pretty steady at 15 inches, except when accellerating, so I don't think there are leaks, when I had a cracked insulator under the carb, it was pretty evident, so maybe the cylinder in the vacuum unit is fluttering or sticking, anyway I will give it a shot of good ole WD40.

Wes

You might also want to check to assure there is not a crimp in the lines

My vacuum unit kept jumping out of gear on the road whenever the clutch was depressed.The gear change lever liked to fall down and was assisted to fall down by the vacuum unit.I stopped the car, climbed underneath and turned the adjuster out 1 turn each time this happened until the gear change lever stayed put.Since then I have not had to adjust the unit.