The Type III automatic transmission
In the mid 1960s, the Type I received an optional "Autostick," which was actually a sort of manual transmission with an automatic clutch. The Type III, on the other hand, received a truly automatic transmission as an option in 1968.
THE TYPE III AUTOMATIC TRANSMISSION INTRODUCTION The Type III automatic transmission is a rare beast, found only in a few of the remaining Type IIIs in the world. The automatic was introduced in 1969 and was VW's first attempt at a fully automatic transmission. In an old advertisement in Road and Track that I've seen, VW claimed that the transmission was so free of resistance that it could be turned by hand when out of the car. This transmission sucks up very little horsepower (which is important on a 64 hp car!) compared to most other transmissions of the period. An automatic Type III takes about 1 second longer to get to 60mph than a manual Type III.
The gear selector is mounted in place of the manual transmission gear
shift (most cars of the period had the gear selectors mounted on the
column). The chrome lever is about 7" tall with a solid black knob on top.
It is mounted in a stylish chrome base, with white on black labeling to
the left. One interesting note is that it is labeled PRN321. The drive
gear is labeled '3' rather than 'D.' [Editor's note: the image above,
from my '71 Owner's Manual, indicates a "D" as the drive gear label.]
There is a starter lockout built into
the base, and the car can only be started with the selector in the 'N'
position. The reverse light switch is also built into the base. There is a
locking mechanism that prevents the selector from being knocked into
reverse or park without the knob being pulled up. This feature is probably
no longer operational on most remaining models.
OPERATION (from the Haynes manual)
The automatic transmission dispenses with the conventional clutch and
manual gear change. Instead a fully automatic three speed gear system,
which changes itself when required, is allied to a torque converter which
only transmits the drive to the wheels when the engine is speeded up. It
comprises two basic parts - the torque converter and the three speed
epicylic gearbox.
The torque converter is a form of oil operated turbine which transmits the
engine power from a multi-bladed rotor (the pump) directly connected to
the crankshaft to another multi-bladed rotor (the turbine) directly
connected to the input shaft of the transmission. At low engine
revolutions, the oil driven by the pump has little force imparted to it,
so the turbine does not move. When the pump speed increases, the force of
the oil is transferred to the turbine.
An intermediate multi-bladed rotor (the stator) regulates the flow of oil
back to the pump after it has done its work through the turbine.
The gearbox consists of a planetary gear set in constant mesh and the
selection of the gears is by braking one or more of the components of this
gear set.
This braking is effected by one of three servo operated multi-plate
clutches and a band - literally a brake band, which can be applied to the
outer ring gear of the set. The automatic operation of the three clutches
and the low speed band is the complicated part, involving a
servo/hydraulic pump system controlled by road speed, inlet manifold
vacuum, and the position of the accelerator.
SPECIFICATIONS
Gear Ratios
First...........2.65:1
Second..........1.59:1
Third...........1:1
Reverse.........1.8:1
Final Drive.....3.67:1
Maintenence
Check fluid level every month.
Change ATF every 2 years.
Uses 7.8 pints/3.6 litres/3.9 quarts of Dextron type ATF
fluid
GRAHAM'S PERSONAL TIPS
In my opinion, the VW automatic transmission is a bit crude, but it gets
the work done. My car has 97k miles on it and I've had very little trouble
and zero failures with my transmission. One thing to check is the
condition of the oil pan gasket. These are made of cork and will
deteriorate due to the corrosive effects of ATF fluid and age. I replaced
the one on my car a few years ago. It still appears to leak (would it be
a VW if it didn't?) but not nearly as badly(*). I top off the level two or
three times a year. Now perhaps it's because my transmission is wearing
out, or perhaps it's a design quirk, but I have to keep my fluid level at
or slightly above the full line. Otherwise the transmission sometimes has
trouble finding third gear. It's been like this for the past 30k miles so
I'm not real worried about it. Another quirk with my example is that the
fuel injection was removed by the previous owner, along with the kickdown
switch. The kickdown switch is supposed to shift down a gear under heavy
acceleration. For example, if you are going 45mph and punch the
accelerator, the transmission should shift to second gear. Mine will still
downshift at speeds under about 30 mph, but I often have to shift down
manually to negotiate steep hills. I have been told that the engine case
for automatic Type IIIs is unique - that is the AS21 universal case will
NOT work with this transmission. If you have an automatic Type III and are
in need of a new engine, you should check with an engine builder to
confirm this. New Type III engines are available from VW for about $1300.
If anyone has any comments or suggestions on these autotranny tips,
please email me, Graham, at gthomas@spsu.edu.
(*) Craig Woolston, cwoolsto@ladc.lockheed.com, has some additional insight into Type III autotranny leaks. He writes:
I read Graham Thomas autotranny tips and know why it still leaks even though he changed the pan gasket. I have several automatics and finally discovered that the seal between the final drive unit and transmission case goes bad. It is an easy fix if you already have the engine out for some other reason. I could not seem to buy just the seal, but you can get rebuilding kits from tranny houses which include the pan gasket for about 15 bucks. Once the tranny is on the ground you take the four nuts off the studs that hold the two pieces together, split the two, and replace the seal. Bang your done. Pretty easy and no more tranny puddles in the driveway. I have two trannys that lasted over 150k and currently running used ones from the junk yard as replacements. The tranny really is a hardy beast. Craig ------------------------------------- Craig Woolston '70 Sqback '71 Fastback cwoolsto@ladc.lockheed.com