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Re: [T3] Starter Question

On 4 Jun 2005 at 11:19, John Jaranson wrote:

> OK, I put in the new switch and everything is back to normal.  Starter 
> spins better than it has in awhile.  The old switch is very rough in 
> its action.  The new one is nice and smooth.  I suspect it was getting 
> worse and worse and finally just couldn't pass enough current to spin 
> the starter.  I will be adding a solenoid into the system later this 
> weekend to save the switch from having to pass all of the starting 
> current.


The starter solenoid is, amoung other things, a relay. This relay, however, has 
other duties, so it still takes a fair amoung of current to operate it. The 
fact that this current has to run all the way up to the steering column 
sometimes makes this a problem, because the long run leads to voltage drop in 
the wire, which may make the solenoid not work. 

In your case, you've already replaced the switch with an aftermarket one, and, 
IIRC, your switch is mounted in the rear seat kick panel. This means that your 
wires are a LOT shorter than the OE wires, so voltage drop is much less of a 

Since the other reason to add a relay is to save the OE ignition switch 
contacts, which you aren't using, I'd say just forget it. It's really no 
benefit to you. You MIGHT want to watch out for an aftermarket switch made for 
6V service, since this would be rated for more current, and it might last a bit 
longer for you.


VW used 2 different clutch diameters (180mm & 200mm) and 2 different ring gears 
(6V & 12V.) (When we talk about 6V or 12V flywheels, we are talking about 
differences in the ring gears, as Russ explained.) Just to keep this all 
interesting, early cranks used a simple gasket between the flywheel and the 
crank while late ones used a rubber O-ring. There are 8 possible combinations 
of these, but VW only ever used 4 of them.

Okay, checking the microfilm, I find that type 3s got:

180mm clutch plates (in 6V flywheels w/non-O-ring cranks) up thru the end of 

200mm disks (in 6V flywheels w/non-O-ring cranks) up to late '66 (dual carb 
engines up to T 0 210 166)

200mm disks (in 6V flywheels w/O-ring cranks) in late '66 only. This is a rare 

200mm disks (in 12V flywheels w/O-ring cranks) from '67 on.

You must have one of the '66 versions, and you should be able to tell which 
from your engine number, since I believe you are still using the original 

If you wanted to change to a 12V starter, you would have to use a 12V ring gear 
to mate properly with it.. This conversion is straightforward IF AND ONLY IF 
you already have the late O-ring crank. If you do, you can install the latest 
flywheel on your crank, reset the end play, and then grind away the extra 
material inside the bell housing that is required to clear the slightly larger 
12V ring gear.

The details on this conversion are covered in the Bill Fisher book, as well as 
in numerous other places.


A 6V starter MUST be used with a 6V flywheel, and any 12V starter will work 
only with a 12V flywheel. The center to center shaft spacing is the same, but 
VW changed the teeth so they would mate up. The starter shaft diameters are 
different, however, so if you change starters you must change bushings, unless 
you use the AT starter. The old bushing won't interfere with the AT starter.

6V vs. 12V]

The main advantage is just as you stated. Because the voltage has doubled, we 
get the same amount of power with 1/2 the current. This makes it easier on 
everything, especially the switch contacts. There is a bonus in that reduced 
current leads to reduced voltage drops, which are doubly less important now, 
because we now have twice as much voltage to start with. (ie, consider how 
important a voltage drop (loss) of 1V would be in a 6V system compared to a .5V 
drop in a 12V system.)

Jim Adney, jadney@vwtype3.org
Madison, Wisconsin, USA

List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org

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