Clutch release

Started by AdrianUK, 08 June 2019, 14:59

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AdrianUK

Hi I'm new to this forum and hoping someone can help, I've recently rebuilt a 1973 auto beetle and the transmission seems to work ok, but the clutch doesn't want to release so I cannot get into neutral without stopping the engine. Can anyone tell me how to adjust this or fix the issue...thanks

autonewbie

Hello,
I am no expert but I have done a good bit of work on my autostick.  You say the clutch is not working. Have you looked at the clutch servo while someone tries to go into neutral?  (The engine needs to be running) The servo can has a protruding arm that must move to operate the clutch. I would look to see if the arm is moving. If it is not moving when the shifter is depressed, then the servo has an issue or the Control valve has an issue, or the shifter points are not providing ground to the control valve. Also a lack of vacuum might be the cause.
Let me know what you are able to check out. It is a real simple system to repair.
Ken
When I  was 15 I wanted a Ghia....It only took me 47 years to get one!   1970 Karmann Ghia Autostick.

AdrianUK

Hi thanks..I can't check for a few weeks as going away tomorrow...but it gives me ideas to check out...can you tell me is the clutch supposed to release when you depress the stick?...and how do I access the points on the shifter?....is there adjustment on the control valve?

Cheers

autonewbie

Before we get too deep into this I need to know a few things.
1. How long have you owned this vehicle?
2. Has it ever run correctly and shifted corrected while you have owned it?
Or is this vehicle new to you and you have no idea if/when it ran and shifted?
Ken
When I  was 15 I wanted a Ghia....It only took me 47 years to get one!   1970 Karmann Ghia Autostick.

AdrianUK

New to me, rebuilt it and only recently started to use it, it has never shifted correctly... it goes into gear great, and I can shift up L-1-2 .. getting it into neutral is the issue

Thanks

autonewbie

OK it is new to you and has never shifted correctly.  Neutral is your issue.  Because it is new to you I want to make sure you have an understanding of how the system works. Mine seemed to shift correctly buy had issues,
The transmission uses electricity, vacuum, and proper fluid. I like to test the electrical first, it is simple to test.
There are two electrical connections on the control valve. This valve is mounted on the rear firewall (in the left corner on my Karmann Ghia). This control valve has two electrical connections One connection has 12volts on it when the ignition switch is on. The other connection is looking for Ground when the shift lever is depressed. You can clip a light bulb or a test meter across these connections and see if the bulb lights up when you press the shift lever. If it lights then you know the CV is getting the ground signal from the shifter and 12 volts from the ignition.
The usual suspect with transmission issues is Vacuum. The vacuum does most of the work and needs to be strong and leak free. The control valve directs the strong vacuum to the vacuum servo under the car. The strong vacuum is derived from the large vacuum port on the intake manifold located under the carb. This port must be crack and leak free. The large vacuum hoses must be in good shape and leak free. Using wire reinforced hose is the proper way to go. Using heater hose or other hose will result is hose collapse and failure. There is a vacuum tank which needs to be in good shape and leak free.
The control valve also uses weak vacuum which is derived from the rear of the carb. Your carb MUST be an autostick carb that is equipped with the correct vacuum port for the control valve. Using the distributor port or other port will cause issues. Over the years carbs get swapped and this item needs to be verified.
Once these hoses, connections, correct carb, Good vacuum tank are checked, then we can look at the vacuum servo for correct operation. A common failure is a small tear in the servo diaphram.
If these items are in good shape, then there are small adjustments one needs to check.
Before anything gets adjusted lets certify the above items.
Might look like a lot of things to check but remember these cars are old and hoses fail etc. Once these are in good shape the car is very reliable.
When I  was 15 I wanted a Ghia....It only took me 47 years to get one!   1970 Karmann Ghia Autostick.

AdrianUK

Thanks..all hoses are new but guessing its e.ectrica, as nothing happens when I depree the shift lever, I'll check when I get back fro. Vacation

68autobug


Yes, You need to see if the clutch arm actually moves when You move the gear shifter either forwards or backwards.... it only works in those positions so if you accidently move the shifter sideways nothing happens...
If the clutch arm is NOT moving... then check the fuse in the engine compartment... You can connect power to the control valve straight from the carburetor automatic choke or fuel cutoff....  If the clutch arm doesn't move with the gear shifter, then connect a ground wire to the terminal that is not connected to power.... and it should click and the clutch arm should move....  that means the gear shifter is not working....  Can You start your car in gear?? You shouldn't be able to due to the neutral start switch...

LEE in Australia..
-- Helping keep Autostick beetles on the road --
   -1968 Silver metallic 1600 single port Beetle - with BOSCH  SVDA and new BROSOL H30/31 carburetor with GENIE Extractor exhaust system with a quiet thunderbird muffler

http://photobucket.com/68autobug