Latest Reader Questions (Oct. 8, 2017)

Here are the latest reader questions, along with my replies:

Ron asks: I once drove a VW bug with a semi-automatic transmission.  It had a four-speed shifter, but no clutch pedal. You would just let off the gas, and change gears.  Does anyone still make this?

My reply: Ah, VW’s Autostick transmission! It was a modified manual transmission that used a vacuum/solenoid-actuated clutch instead of a floor-mounted/manual clutch pedal. This eliminated the foot-actuated clutch pedal on the floor, but the driver still had to manually shift gears (i.e., it did not shift automatically).

VW abandoned this transmission circa 1976. Probably because most VW buyers preferred the manual manual, which performed better and was less problem prone.

Most modern automatics have both fully automatic and driver-controlled “manual” shift function. But the closest-in-concept to the old Beetle’s semi-automated manual transmission are the fully automated manuals available today. Such as VW’s currently available Direct Shift (DSG) gearbox.

These are true manual transmissions (as the old Beetle’s was) but unlike the old Beetle’s, they feature fully automatic operation – including gear change operation. Left in Drive, these function like a conventional (hydraulic, with a planetary gearset) automatic except they are more efficient (because there’s no slippage through a torque converter) and shift much more quickly. This is why these transmissions have become popular – for both performance and fuel efficiency reasons.

They are, however, also more complex and – when they fail – can be very expensive to repair/replace.

Steve asks: I have heard this term referring to an exactitude of engine rebuilding – that it has been blueprinted. What is the real meaning of this term? Is this a process performed by a specific type of qualified mechanic? What do engine blueprints look like?

My reply: “Blueprinting” an engine generally refers to following all factory specifications (e.g., tolerances) listed in the service manual* to the letter, using the necessary precision tools to assure conformity exactly… as opposed to “close enough.”

Usually, “balancing” goes along with “blueprinting” – the former term referring to equally close attention paid to making sure the rotating assembly  (e.g., pistons, connecting rods, the crankshaft) is perfectly balanced, this being of major importance in a high-performance application for all the obvious reasons. A slight imbalance that would probably not cause any problems in a grocery getter could result in a catastrophic failure in a 7,000 RPM weekend racer.

*The “service manual” referenced here means the factory service (or shop) manual, not the aftermarket manuals you can buy at auto parts stores such as Haynes and Chiltons manuals.  These are okay for general service work but are not as detailed as the factory service/shop manual.

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Got a question about cars – or anything else? Click on the “ask Eric” link and send ’em in!

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