Trouble with my 1968 Semi Automatic Transmission (Page 1 of 2)

Hiya Darren,

First off, know this......................90% of the problems you might encounter with an AutoStick transmission can be fixed WITHOUT having to split the transmission case and get at the internals.  Chances are your problem lies in one of the "support systems" for this transmission.

I'm a believer in trying the easiest approach first, so let's do this...........  rummage around in your engine compartment.  You'll be looking for an in-line fuseholder.  On my car (a 1970) there are two of these.  One is for the control valve solenoid, the other is for the back-up lights.  I'm not sure if you will have both in a 68, but you will have at least the one for the solenoid.  Probably located close to the control valve and attached to the fan cooling shroud.  Check to make sure that this fuse is intact and the connections are clean.
Everything OK there?

Step two......hop into the passenger cabin.  Look closely at the blue wire coming out of the bottom of your shift lever.  You mentioned tracing this back to the solenoid......good!  Now take a very close look at the point at which the wire exits the shift lever.  Is the insulation intact?  No shorts?

Step three..........you mentioned tracing the blue wire back.  Did you examine the under the rear seat connector closely?  Everything tight AND bright and shiney?

Step 4.........take another look at the connections on the solenoid.  Nice and tight?  Bright and shiney?

OK.............that's the easy stuff.  Everything else includes taking things apart and/or crawling around under the car.  So, let's do this........go through the four steps above.  If they don't help, repost here and I'll fill you in on Plan B - nothing overtly difficult, but it will take a little wrenching.

Mike

1970 AS Bug

Hiya Darren,

OK, assuming everything is just fine so far, we move on to Plan B.

We'll pick up right where you left off, with the question about testing the wire to the solenoid.  Here's a little context for what's coming up...........The power wire (it's red in your picture) to the solenoid is always hot (provided the ignition key is in its "on" position) and the black wire to a switched ground (more about that later).  So, what you do is pretty straightforward.........set your multimeter to 20 in the DC range and touch your red lead to the solenoid terminal nearest the engine.  Touch your black lead to the bolt on the distributor clamp.  You should get a reading of around 11.00.  Now try switching the black lead to the solenoid terminal farthest away from the engine (still holding the red lead in place).  You should get a reading of 0.  Have Paula hop in the car and depress (she does not have to shift it) the shift lever.  With both leads still in place you should see the multimeter jump up to around 11.00 again.

If it does, then this test tells you that your solenoid is suspect.  If it does not then you have either a problem with the solenoid or the shift lever.  The shift lever is that "switched ground" I referred to earlier.  When it is depressed it makes a contact inside the lever which completes the ground/circuit to the solenoid.

Let's assume that you did not get a reading when you hooked up the solenoid terminals and hit the shift lever.  Easiest thing to do at this point is to remove the solenoid.  Four standard head screws hold it to the control valve.  Just remove them and pull the solenoid out - it goes back in the same way.  There is a spring involved here but it is easy to compress on reassembly - you'll see what I mean when you remove the solenoid.  Now hook up a couple of leads (just as we did before) to the solenoid and touch them to a good battery.  The center post of the solenoid should pop out.  If it does not - you have a crummy solenoid.  If it does, your problems lies in the shift lever and its contacts.  We can cover that later - and by the way, if I were a betting man, and I have been known to take a wager or two, I'd guess the problem is more likely to be in the shift lever than in the solenoid.  The shift lever is a matter of adjustment while the solenoid is an integral unit.  But I have seen solenoids go south too.

A word of advice Darren, if you do not have it already, you definitely need to get a copy of Bentleys Official VW Service Manual.  Go to Amazon and type in "Volkswagen, Bentley, Service" into their search feature.  Your book should come up as number 6.  The Bentley will give you detailed instructions on servicing most AutoStick related components.  You need this book now, and you will find it useful in the future.  Good prices there also.

Lastly, do know that going through the procedure outlined above will take you through the AutoStick electrical system.  However, it is possible that your problem could lay somewhere else.  If so, we can handle that in turn.

Let us know how you make out.

Mike

1970 AS Bug

Hiya Darren,

The hiss is a good sign that the clutch servo diaphragm is intact and holding a vacuum.  However, it is possible that the vacuum system could still have some problems.  In other words, hearing that hiss, while a good thing, is not the definitive way to tell whether the vacuum system is operating as designed.

Let us know how you do with the electrical tests.

Mike

1970 AS Bug

Hiya Darren,

Hmmmm...............let's revisit step 4.

Try this instead.......Hold the red lead to the left terminal (the one closest to the engine).  Touch the black lead to the right terminal (furthest away from the engine).  You do not want both test leads on the same terminal.  Get a reading on that setup when your wife depresses the shifter.  If you get a reading of around 11.00 that tells you that an electrical "signal" is being sent to the solenoid (and that the solenoid is likely kaput); a reading of 0.00 tells you that that the problem is "upstream", probably in the shifter.

Mike

1970 AS Bug

Hiya Darren,

OK.....................on we go...............

We have some potentially conflicting information.  The click you hear when Paula depressed the shift lever and the 0.00 reading could be at odds.  Possibly not. 

Here's the scoop..............your solenoid is always "hot" as long as the ignition key is switched on.  What actually makes it work is the completion of the ground so the juice flows from the coil attachment point through the solenoid, pops out the shaft, and continues along to the ground.  That ground is inside the shift lever.  When the driver presses down to shift, a contact is made inside the shift lever so the circuit is completed.

Given that, you should not get a reading of 0.00 and hear a click in the solenoid.  You could hear a click if the circuit were being completed, or should not hear a click if the circuit were not being completed.  That make sense so far?

Notice that I previously mentioned, "Possibly not"?  It is possible that you are getting juice to your solenoid, and hearing a click, but the durn thing is not working.  I have seen a couple of solenoids with broken posts or posts which will not fully extend.

So Darren, I'd do this to be sure.  Pull the solenoid off the control valve and, as I mentioned in an earlier post, test it with a couple of leads to a good battery.  That little center post should, if the beast is working properly, pop right out.  If it does then we need to look at the shift lever, the back-seat contact point, and the condition of that ground wire.

And please keep in mind (I know this is a long process and there's a bunch of footwork involved) that your actual problem may NOT be in the electrical support system for your AutoStick.  It's just the most likely place to start looking given your symptoms.

Mike

1970 AS Bug

The arm of the servo is supposed to move, that's what disengages the clutch. If the whole servo was moving, that's a problem. The arm is threaded, and this is how you make up for wear in the clutch plate, just like adjusting the clutch cable on a standard bug. Given your condition I'd be inclined to think it's something clutch related, such as a torn diaphragm in the servo or small hole in the vacuum tank, something like that...However, It's been a while since I had an AS, and you're in very capable hands with Bookwus directing you, so I'll leave him to it. Let us know how it turns out.

Here is some other info that may or may not be relavent.  Sometimes when I used to shift it into gear it would slam into gear.  Othertimes, it would go in nicely as expected.  This was an intermittent problem.  I had called a guy in a city three hours from us that restored VW's to ask him what it could be and he said it was idle speed.  I adjuste that but it did not make a difference.  Could this previous problem be suggesting that something is wrong with the tranny?  I still have not repeated the volateg tests but I will today.

Darren