I changed the clutch on my '69 autostick. Also fixed a vacuum problem. It now shifts much better but when going into reverse or 1st, the whole car shakes from the force of the clutch engaging / disengaging. The adjustment on the control valve makes no difference to this. I carefully set the linkage when I reinstalled, but any guessing that this may be where the fix is. Any ideas? Thanks :(
Hiya mg,
Congratulations on replacing that clutch! Off topic, but where and how did you round up the parts?
The "ker-thunk" syndrome is due (my opinion here based on five year experience with the problem) to your Control Valve. Not that it's out of adjust, but that it just can't do the job (as originally designed) anymore. I have gone through about 10 or 11 Control Valves and found that as they get older and the valve internals (the valve discs, rubber o-rings, and diaphragm) loose their ability to work (again, as designed) to "modify" the shifting action. Rather they more or less function in an "on and off" mode.
When you downshift from first range to low (try this at about 25 to 30 mph) does the car lurch from the sudden deceleration? If so, that's another sign that the Control Valve is not doing it's original job. A properly functioning Control Valve should ease that downshift into effect.
All that having been said, do remember that setting up the clutch to shift properly is a combination of adjusting the clutch arm and setting the Control Valve adjusting screw. Tinkering around with the combination of these two settings can help (somewhat) but the "ker-thunk" will probably still be there to some degree.
Mike
Hi Mike
Thanks for the info. I was wondering about the control valve as the adjustment doesn't seem to make much difference. Any idea where I could get a rebuild kit for it?
I got all the parts for the clutch as well as a new servo rebuild kit from CIP [California Imports] on the web. The VW shop told me I needed a new clutch disc but it turns out that I likely didn't need to go through all that. Once I understood how it worked, I discovered the servo was the real problem.
Hiya mg,
As far as I have been able to determine rebuild kits for the Control Valve went the way of the Dodo in the early nineties. Interestingly there was no such thing as a rebuild kit for the entire Control Valve. There were actually three kits (two for different valves and one for the diaphragm) needed for a complete rebuild. I used to have the numbers for those kits, but believe me, the kits no longer exist. I looked. A lot!
Mike
1970 AS Bug
So what does one do in this case? Live with it until the control valve totally fails and then replace it? Or does it need replacing before it causes more damage?
Hi Everyone,
Mine also THUMPS every time I let the gearshift lever go...
I thought it may be the RELIEF valve on the ATF Pump ....
I have a spare control valve.... I haven't tried the 2nd one as yet, as I thought that after pulling the ATF relief valve out ...
and it may have been stuck or something!! or something easy..
Ohh Well... I might pull the spare valve apart or just try it as it is...
and see what happens...
I'm a Hospital patient 330kms from Home at the moment, but I'll check it out as soon as I can...
I couldn't remember the car THUMPING into gear 8 years ago when I stripped the car for restoration purposes...
I'm also hoping I have a Valve stripped down or diagram in one of My VW Manuals... It would be great if its only an O ring to replace...
But that would be only too easy & too inexpensive ......
Does anyone know if the clutch plate will wear out any faster ??
with the THUMPING ????
Lee Noonan
http://community.com/user/vw68autobug
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Hi Mike,
The part numbers for those kits would be great...
There may be some in Australia ???
New Old Spares NOS parts are popping up all the time..
Maybe I could find some ??
I did see at a swap meet last year , a box full of crankshaft pulley bolts
with the lugs on the head for a crank handle... those were New but very old as You can imagine?? although the Australian Country Buggy made in 1968-69 used them along with industrial & Power generators with VW Engines , used by the Australian Armed forces.......
There were other old soiled VW packets of things...
so, You never know...
I know its one in a million chance.... of finding some...
Most VW dealers changed to another brand of Car when the Australian made 1976 Beetle and Golf were both discontinued ....
Lee Noonan
http://community.webshots.com/user/vw68autobug
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Yes, first I disconnected the small vacuum hose that goes to the carburetor...
Then... NO thumping... but it takes a long long time for the car to move...
even revving the engine didn't help....
then I reconnected to carburetor, which is a small weber that was made years ago for VWs..... Thumping and spinning the rear wheels in the gravel....
so, I took a 2 inch long wood screw with fine thread and screwed it halfway into the small vacuum rubber hose - I then cut the head of the screw off... and screwed a small piece of vacuum hose onto the remainder of the screw, and pushed the hose back onto the carburetor vacuum connection... I will glue the two rubber hoses together to stop any vacuum leaks...
Now, because the screw is restricting the vacuum....
it NOW works perfectly..... NO THUMPING... but still drives perfectly...
I have taken pics of the screw etc... if anyone wants to see what I am talking about....
Lee Noonan -- 68AutoBug -- Australia --
http://community.webshots.com/user/vw68autobug