1968 Beetle Autostick - slow moving clutch servo

[dpin78]

Hi guys,
Got a question regarding my 68' autostick.
She was running perfect until this weekend.

For some reason now it feels like the clutch is slipping. Basically I have to give it lots of gas for the car to move. I thought that maybe my clutch servo had gone bad and wasn't holding pressure. I disconnected the vacuum hose going to the clutch servo and pulled it out manually, covered the vacuum hole with my finger and she holds perfect. Then i figured let me check all my vacuum lines coming in/out of the control valve and I found zero vacuum leaks. I then connected everything back and lifted the vehicle and put her into 1st gear. I went under the car and noticed the clutch servo was pushing out, but super slowly and stops about half way. I tried reverser, low and 2nd gears too and same thing. The clutch servo moves, but super slowly and never goes out the entire way. Maybe moves out about 1/2 inch and never fully out.

I tested my control valve with 12 volts and I can hear the actuator clicking inside. For some reason, even though the control valve is clicking/actuating, I'm thinking that it is not functioning properly and not allowing full pressure to build up. I checked my air canister also and don't see any cracks or leaks when the car is running.

Before I go out and spend $200 on a used control valve, wanted to see if anyone else had any thoughts on this issue.

Thank you in advance!

[sb001]

Check the clutch freeplay as follows:

1. Disconnect the vacuum line to the servo, and pull the servo rod out as far as possible.
2. Measure the distance between the outside edge of the servo mounting bracket and the edge of the adjuster sleeve on the servo. This distance should not be any greater than about 4mm. (You can cut a strip of sheet metal or similar 4mm wide and place between the bracket and the adjuster sleeve to use for this measurement.)
3. If greater than 4mm, barely loosen the locknut on the other side of the adjuster sleeve (watch out, it is BACKWARD threaded so turn it clockwise to loosen it!) and leave the locknut right there. Then screw the adjusting sleeve in toward the servo about 5-6 turns, until you have approx 6.5mm between the locknut and the adjuster sleeve. (You can use another strip of sheet metal 6.5mm wide for this measurement.)
4. Tighten the locknut back down against the adjuster sleeve. You should now have 4mm or less clearance between the servo mounting bracket and the adjuster sleeve.
5. GO for a rip!!
_________________
I'm the humblest guy on this board.

1969 autostick sedan, family owned since new
1600 SP engine
Solex 30 PICT 3 carburetor
Bosch 113905205AE autostick distributor

[dpin78]

Hi,
Took some feeler gauge and measured the adjustment sleeve as you suggested but still same. I tried both tightening the specs and loosening the specs on the sleeve but same results. It’s like it isn’t creating enough pressure to move the servo arm.

[sb001]

If the servo rod seems to be moving outward too slowly, there is a reducing valve screw on top of the control valve in the engine bay (under the small plastic cap):

The clutch engagement speed can be adjusted by turning that screw in or out which allows for more or less vacuum to pass through to the clutch servo. If yours seems to be going too slow, turn that screw counterclockwise (outward) about a half turn which will allow more vacuum to pass through. See if it helps the clutch servo rod move out further and/or more quickly.

This could also correlate with a slipping clutch. Take a look at (c) on #2 symptom on the the following autostick troubleshooting chart:

This seems to be another symptom of the reducing valve screw being in too far, so try adjusting that screw outward and see if anything changes.

If it doesn't help anything, we might have to start considering a faulty torque converter (item #11.)
_________________
I'm the humblest guy on this board.

1969 autostick sedan, family owned since new
1600 SP engine
Solex 30 PICT 3 carburetor
Bosch 113905205AE autostick distributor

[Tom K.]

All of your initial tests regarding vacuum leaks were unnecessary (sorry). You would have checked those things only if your clutch was failing to disengage during shifting (gear grinding).

What you are experiencing is too much vacuum - the clutch isn't letting go after the shift.

Things to try. Add more clutch free play to the servo arm as sb suggests above. I'm not sure that screw on top of the control valve will do much if the problem you are experiencing persists long after you shift, but give it a try. Also, try loosening the shift contact on your stick. It that is too tight then the vacuum is not cancelling after a shift. You can check for this last problem by simply disconnecting a wire from your control panel to see if your wheels spin better (up in jack stands, of course) when in gear.
_________________
'91 Vanagon Westfalia
'70 Beetle Convertible
'71 Super Beetle Semi-Automatic: https://www.thesamba.com/vw/forum/viewtopic.php?t=714131&highlight=
'65 Ghia: https://www.thesamba.com/vw/forum/viewtopic.php?t=762478&highlight=

[dpin78]

Hello SB & Tom!
Thank you both for helping me!

SB: I adjusted the reducing valve screw and all it did was either make it take even longer to move the arm (which would make sense if not enough vacuum is being created) or make the gears 'thump/kick' the transmission. I had adjusted this a few months back and the gear selection was super smooth.

Regarding the torque converter could be a possibility; however, the previous owner gave me a rebuilt unit when I purchased the vehicle and I installed it a few months back and had till now been running okay (but yes I can't discard this possibility)

Tom: Makes sense what you mention regarding the vacuum tests. I did play with the clutch free play, but same results. I have to rev up the engine lots to get the car to barely move at all. I started messing around with the shift contacts. I adjusted it according to the manual and few posts/youtube videos I came across. Same results. Also I tried disconnecting one of the wire from the control valve and same results.

I tested voltage to the control valve and here are my results and would like to confirm with you guys if they are correct or not.
I uploaded 3 images.
1. With Ignition turned OFF I have ground to right side connector
2. With Ignition turned ON and Stickshift in Nuetral position I have 2.7v
3. With Ignition turned ON and Stickshift in selected into ANY gear I have 11.6v.

The left side connector had same 11.6v constant with Ignition turned ON and either in Neutral or Gear selected. Please note the voltage readings were with the engine NOT running, just the ignition turned to the ON position for test purposes only. My Neutral safety swith is working, bc it will not let me turn the engine on if I have a gear selected.

[/img]

[Tom K.]

Do you have plenty of ATF fluid?

Could your clutch disc be worn thin?

I don't think your control valve could be causing the clutch to slip as you are experiencing. It's entire purpose is to *disengage* the clutch to allow gears to shift. If you unplugged the control valve and your clutch is still not engaging, then the control valve cannot be the problem unless the internal valves are leaking air somehow (you can take it all apart to investigate). But the electrical solenoid function of the control valve has been proven innocent in my mind once you unplugged it and your clutch still slipped.
_________________
'91 Vanagon Westfalia
'70 Beetle Convertible
'71 Super Beetle Semi-Automatic: https://www.thesamba.com/vw/forum/viewtopic.php?t=714131&highlight=
'65 Ghia: https://www.thesamba.com/vw/forum/viewtopic.php?t=762478&highlight=

[sb001]

Agree with Tom above. But just for kicks I did the same test, with more or less the same results (except my wires are reversed from yours on the control valve solenoid, but it wouldn't make a difference.)
I am fairly confident you are looking at a mechanical issue. My guess is the torque converter. How is your ATF fluid level? I don't suppose you see any obvious leaks?

You can try the stall speed test to check for a faulty torque converter but you'll need a tachometer:
1. Turn the car on
2. Apply the e-brake and hold the brake pedal down TIGHT with your left foot
3. Put the car into Drive 2
4. Holding the brake pedal TIGHT with your left foot, floor the accelerator with your right foot for a few seconds- just long enough to check the tach reading. When doing this test the engine should run at a reduced "stall" speed of around 2000-2300 RPMs instead of revving way up.
5. If the speed is below this, the TC is faulty. If it's above this, either the clutch has issues or the TC is not getting proper ATF pressure. You can do a pressure test on the ATF hose coming up from the oil pump going to the TC, should be around 52 PSI.

I can't think of much more that would cause this other than ATF fluid or something on the clutch face that would make it slip. When you installed the rebuilt converter you did remember to put the TC bolts back in correct?
_________________
I'm the humblest guy on this board.

1969 autostick sedan, family owned since new
1600 SP engine
Solex 30 PICT 3 carburetor
Bosch 113905205AE autostick distributor

[dpin78]

Could def be worn down clutch disc. Just kinda weird that it happened all of the sudden. Would have imagined that it should’ve given signs of failure.

ATF fluid is to level and no leaks found.

Makes sense. I guess it’s not the control valve. Unless it’s failed internally.
So I’m guessing the voltage drop to 2.7v is normal on the ground? Wasn’t sure if that should be full ground when the shifter grounds it.

[dpin78]

Hi SB,
New ATF was used when I installed the rebuilt converter. Less than 300 miles on it. Level is good was actually the first thing I checked forgot to mention No leaks either.

I ordered a tachometer on Amazon. Should have it by tomorrow and wi report results within a day or two.

What tool/pressure tester did you use for the pressure test on the ATF hose coming from the oil pump? Would def like to run this test too!

It’s been a few months since I put the TC back on. Don’t remember to good how I put them on, But what would be the wrong way of installing them? Weird thing is she was running fine until this past weekend.

Thanks for the advice as always! Much appreciated 🙏🏼

[Tom K.]

I really hope you can find the problem. Pulling the engine and transaxle won't be fun. If it comes to that, them my money is on some fluid (ATF, motor oil, transaxle oil) all over your clutch disc instead of a worn disc. Did you peen the oil seal onto the drive shaft before installing the torque convertor?


Link

_________________
'91 Vanagon Westfalia
'70 Beetle Convertible
'71 Super Beetle Semi-Automatic: https://www.thesamba.com/vw/forum/viewtopic.php?t=714131&highlight=
'65 Ghia: https://www.thesamba.com/vw/forum/viewtopic.php?t=762478&highlight=

[dpin78]

Yeap hoping it doesn’t come down to that.
Yeap def peened it in a few spots. I watched his video prior to putting it together. Haven’t looked yet and hope i don’t have too but do you know who sells the clutch kit for the autosticks? Also any good videos/posts on how to replace it? Tks!

[Tom K.]

And before you tear apart your control valve, first do this. With the car idling and on jack stands and in gear, just disconnect the vacuum hose on the servo. If wheels start spinning, then your control valve has a (non electrical) internal problem. If the clutch is still not engaging with no vacuum to the servo, then I'm afraid you'll be pulling the torque convertor or inspecting the clutch disc. We've all been there.
_________________
'91 Vanagon Westfalia
'70 Beetle Convertible
'71 Super Beetle Semi-Automatic: https://www.thesamba.com/vw/forum/viewtopic.php?t=714131&highlight=
'65 Ghia: https://www.thesamba.com/vw/forum/viewtopic.php?t=762478&highlight=

[Tom K.]

Clutch discs are a pain to find. But luckily they wear *very* slowly. So my suggestion is to buy a complete transaxle on the Samba classifieds for maybe $100 if you're lucky. Then hope (expect?) the disc to be good on that transaxle.
_________________
'91 Vanagon Westfalia
'70 Beetle Convertible
'71 Super Beetle Semi-Automatic: https://www.thesamba.com/vw/forum/viewtopic.php?t=714131&highlight=
'65 Ghia: https://www.thesamba.com/vw/forum/viewtopic.php?t=762478&highlight=

[sb001]

[Marcdeb]

I have little experience here other than lots of reading and driving my Autostick last summer, but is there any known issues of ATF not circulating for whatever reason? Like kinked ATF hoses, blockage somewhere, or ATF pump failure?
_________________
Marc
68 Karmann Ghia Cabrio Autostick
71 Karmann Ghia Cabrio

Previously Owned:
2011 VW EOS Hard Top Conv
2008 Saab 9-3 2.0T Conv
2003 Saab 9-3 SE Conv
2001 Saab 9-3 Conv
1998 BMW 3 Series Conv
1997 Saab 900 Conv
1997 Mazda Miata

68 Ghia Vert Survivor with 22,350 miles: https://www.thesamba.com/vw/forum/viewtopic.php?t=768107&highlight=
71 Ghia Vert Restoration: https://www.thesamba.com/vw/forum/viewtopic.php?t=726710&postorder=asc

[sb001]

[dpin78]

Hi Tom,
Had a little time today after work to perform the test you mentioned.
- Car lifted on jacks
- Car idling and set into gear (1) wheels spinning slowly at this point
- Vacuum hose disconnected
- Wheels kept spinning at same speed prior to hose disconnect and no further movement from servo arm, which I would assume my original persists and I’m looking at having to pull the TC or clutch disc.
- Ever so slight suction felt at hose coming from tank.

I’ll perform the tachometer and atf psi test tomorrow and report back prior to pulling anything out.

I’ve attached a link to a small video of the test performed today:
https://youtube.com/shorts/zSQAC7MARfU?feature=share

[dpin78]

Hi SB!
I should have some time tomorrow to test atf psi and perform the tachometer test. I’ll record and report back.

No previous work at all since I put her all back together a few months back. I purchased it with the engine out. PO had purchased a rebuilt TC and then his mechanic that was doing the job left him high and dry. He didn’t want to deal with it and sold it to me. I asked him why did he change the TC and said bc the rear main was leaking and took advantage that it was out. I’m thinking now that maybe he wasn’t honest with me and it was already having similar issues and his mechanic told him it was the TC, when in fact the clutch was going out already. Maybe the rebuilt TC bought me some time and I was able to squeeze the last few miles out of an already worn out clutch?

She was purring like a kitty prior to this weekend driving solid around town. I’ll take some pics tomorrow of the engine bay and post.

[Tom K.]

Ok. In my mind your control valve is off the hook - both electrically and mechanically. And you should feel very little vacuum. So it looks ok.

Clutch disks wear so very slowly on these cars. I wouldn't expect that to be the problem. You can page through the link below in my signature for the 71 where I show pictures of how I examined my clutch. I'm still using that same clutch disk.

The torque convertor story is intriguing. Maybe the last mechanic *thought* this same problem was a bad torque convertor? But why was it driving well for a little while? Hmm.

Does the ane problem occur in all four gears?
_________________
'91 Vanagon Westfalia
'70 Beetle Convertible
'71 Super Beetle Semi-Automatic: https://www.thesamba.com/vw/forum/viewtopic.php?t=714131&highlight=
'65 Ghia: https://www.thesamba.com/vw/forum/viewtopic.php?t=762478&highlight=