Hiya All,
I just stumbled across a piece about AutoSticks I'd written some years back. Inasmuch as this forum is focused on AutoSticks, I thought there might be some folks out there who could get some useful information from this piece. So......here it is............
Trouble Shooting an Auto-Stick
A Little Background
Prior to the Auto-Stick, Volkswagen had marketed a wholly mechanical semi-automatic transmission in Europe called the Sax-o-matic. Encouraged by the response of customers in Europe and with an eye on the increasingly upscale market in the United States, VW began development of an improved semi-automatic transmission in the mid sixties. VW introduced its Automatic Stickshift transmission in 1968. It was available in Standard Sedans, SuperBeetles, and Karmann Ghias throughout its production run.
The Nature of the Beast
Basically, the Auto-Stick allows for driving without the necessity of shifting gears, as in a manual transmission. For that matter, many trips may be made without shifting of any kind. However, it is not an automatic transmission in the sense that term is used today. Technically, the Auto-Stick is a dry-clutch, three-speed, semi-automatic transmission.
The driver, unemcumbered by a clutch pedal, has the option of going through the gears as one would with a manual transmission; Low, First, and then Second. Shifting occurs by simply moving the shifter to the desired position while easing off the gas pedal. Or the driver could simply leave the shifter in First for around town driving. Although the start off the line is slow, the driver even has the option of setting the transmission in Second and leaving it that range as he drives.
The shifting pattern is in a typical three-speed ³H² format. Upper left is Reverse, lower left is Low, upper right is First, and lower right is Second. Reverse, as with all VW transmissions of the day has to be depressed to engage.
VW refers to the AS shifter positions as ³ranges². Low range is designed for starting off under a load or uphill. First range accommodates most around-town type of driving speeds up to approximately 45 MPH. Second range is the choice for highway driving speeds.
Checking Out the Auto-Stick
Shifting gears in an Auto-Stick is an electrical operation accomplished with the aid of a vacuum assist. There are many individual components to the vacuum assist system, such as the hoses, clutch servo, control valve, and vacuum tank. This being the case, it is almost always a good idea to troubleshoot the vacuum system first when something goes wrong.
The Vacuum System
Leaks anywhere in the vacuum system can result in symptoms such as poor (slow or jerky) shifts. Actually, the vacuum hoses and their clamps should be replaced on a regular basis (like every 10,000 miles). So, look the hoses over carefully for signs of wear or cracking. Also check to see that the hoses are keeping their natural shape; which is to say......not collapsing. Hoses in the vacuum system should be wire-reinforced. Also while doing this inspect the clamps and be sure they are tight.
This is also a good time to thoroughly examine your vacuum tank (under the driver¹s side rear fender) for leaks. It is prone to gravel spray
from the rear tire. Lastly, in doing a ³vacuum check² take a good look
at the control valve and the clutch servo. The control valve is
not likely to be leaking (although that is a possibility) but may
need to be adjusted. See any good manual (Haynes or Bentley. Having at least one of these manuals is an absolute necessity.) for
this procedure.
This would be an excellent opportunity to remove the control valve air filter and clean it out. Another chore to do while you¹re back in this area is checking the Automatic Transmission Fluid level in the ATF reservoir. The ATF dipstick is built into the reservoir lid which can be found on the right hand side of the engine compartment. The fluid should be checked while warm, but the engine should not be running.
The Clutch Servo
The clutch servo may well be where you are experiencing any possible leaks. Check it carefully to see that it holds a vacuum. To check the servo for leaks, remove the vacuum hose from the control valve where it attaches (the vacuum opening) to the servo. Move the clutch arm toward the rear of the car so that the servo¹s internal bladder is pulled out of its resting position and fills the servo with air through the vacuum opening. Place your thumb over the vacuum opening and observe the bladder action through the holes on the side of the servo. If the bladder deflates, you have a leak. Replacing a clutch servo is rather common in an Auto-Stick with more than a few miles on it. Rebuild kits are readily available and of reasonable cost. The only real hassle involved with the clutch servo is its location, which is just above the left heat exchanger. To remove or adjust the servo, you¹ll likely have to remove that heat exchanger first.
If the servo bladder holds a vacuum in the test above, your servo is airtight, but may need to be adjusted. Actually, what is really adjusted is the clutch free play. This can be accomplished by following the directions (you¹ll have to make a gauge too - the directions for that are in the manuals also) in either Bentley or Haynes. Should you find that you cannot adjust the clutch free play ³out² any more, you will have to remove the engine and replace the clutch.
The Electrical End
So, let¹s say your vacuum checks out. Next, try the electrical end of all this. Your shifter has a set of points within it. Normally the action of moving the shifter will cause the contacts to touch and complete the circuit to the control valve. When these points make contact the Auto-Stick can do its job and the driver is able shift the transmission. Poor contact or no contact is going to result in gear gnashing and other assorted transmission horrors. So you¹ll need to check out the condition and the gap of your shifter points. Again, a good manual can instruct you in this procedure.
While you¹re down there adjusting the points, trace that blue wire coming out of the bottom of the shifter. It should lead back under the rear seat to a connector. Because this connection leads back to the control valve, it must have a solid contact at this point, so check that out. But you¹re not finished here. Back in the engine compartment (usually in the upper left hand corner near the coil) you¹ll find two in-line fuse holders. One of those fuse holders governs the back-up lights. The other one which will have a lead connecting to the solenoid on the control valve transmits power to the control valve. Check to be sure that this fuse is in good shape and its contacts are clean.
It would also be a good idea to get a continuity checker and check out the electrical switches (the neutral safety switch and the ATF temperature switch) on the transmission itself (they¹re over on the passenger side of the tranny behind the right heater box head).
Something Else
If everything mentioned so far checks out well for you, remember this; the better shape your engine is in (all things being equal) the better your Auto-Stick will perform. Due to its vacuum connections, the Auto-Stick is more sensitive to a well tuned engine than a manual.
Take a good hard look at your carburetor, especially around the area of your vacuum lead to the control valve. Look for any gas leaks; anything which might indicate a loss of vacuum at that point. Check your carburetor adjustment. Regap the points and plugs. Retime your engine. In short, make sure your engine is tuned up.
Do Know This
Although it adheres to the basic Volkswagen philosophy of good, sound transportation, the Auto-Stick transmission has been frowned upon by a number present-day VW fans. Changing Auto-Sticks over to manuals has spawned several kits aimed at helping to accomplish this task. Yet the Auto-Stick itself is a reliable and functional transmission. Many of the parts, such as the case and reverse gears are actually built to higher tolerances than the manual. If well maintained, the Auto-Stick will deliver many years of dependable and useful service. Most of the problems encountered by Auto-Stick owners can be handled by observing the procedures listed above in this article.
Mike 70 AS Thanks for all that information Mike.. Much appreciated. I have bought 7 different VW Workshop-owner manuals to know everything I can about the stickshift... all from the USA.. the only one I need now is the Bentley VW of America workshop manual.. I am totally restoring My 1968 Autostick Beetle , and it should be ready by October at the latest... Fingers crossed... I Also Agree that the Autostick isn't a difficult car to own... Just keep the clutch adjusted and the clutch will last a long long time... and replace the hoses with the best quality You can find, and replace all the small ones every year or so... I have pulled mine apart to see how it worked and its condition. As My car was owned by a VW trained Mechanic, Mechanically its in Very good Condition..
I was led to believe that PORSCHE made the Sportomatic transmission for the 911-912 Porsche in 1967-68.. Devised by Fichel & Sachs for the US Market. It was available in 1967 in Europe and 1968 in the US..
By the early 70's, sales of the Porsche sportomatic in the US was practically Nil, although it was still available as an option untill May 1979.
The Major difference being, the Porsche stick shift used the same oil as the Engine .... instead of a seperate supply of Auto Transmission oil.....
I would rather have independent oil supplies for the Engine, Torque converter and the gearbox. The Porsche 911L Sportomatic had a Porsche 4 speed Gearbox.. where as the VW has only 3 speeds. Both Clutch units being made by Fischel & Sachs.