[s-cars] 3B Distributor

Peter Schulz pcschulz at comcast.net
Wed Jun 7 21:46:37 EDT 2006


better to post this to the 200q20v list, but here goes...


You could consult Bentley manual, but it says to remove the IM which 
I found  unecessary.
J have found that removing the ISV gives some additional room to 
access the 13mm Nut that holds the distributor to the head.
But before that you will have to remove the distributor cap and deal 
with the anti tamper cover if the distributor was never before replaced.
I used a combination of a dremel with a cutting disk and a chisel, 
but I think that cutting a slot into the bolt would allow you to 
remove it with a screw driver with less drama and work.

Bernie Benz instructions on replacing the distributor gear with a 
plastic gear below:

 > I.  Preliminaries: Bentley refs  3B: 28.47, early 7A: 28.250
 > (The Audi distributor alignment tool is not necessary.)
 > 1.  Rotate the engine to #1 TDC.  Rotor pointing to #1 plug terminal and
 > 0-degree flywheel mark at pointer edge.  Get this right!
 > 2.  With dist cap and Hall sensor connector removed from the dist and other
 > junk out of the way (like the 3B intake manifold) as much as possible, note
 > the angular position relative to horizontal (3B), or vertical (7A) 
of the Hall
 > sensor connector and the rotor (these will be opposite each other) for later
 > return to original oriention purposes.
 > 3.  Remove the anti-tamper cover, if any, on the dist hold down clamp nut,
 > located on the stud in the head under the dist location hole, remove nut and
 > clamp.
 > 4.  Pull dist from its locating hole, noting that the rotor turns clockwise
 > about 1/4 inch as the dist gear is withdrawn from its mating cam gear.  Upon
 > reassembly it must go back in with this same final removal 
orientation to end
 > up in the same original position.
 > II. Plastic Gear Removal:
 > 1.  Don't try to drive out the retaining pin yet!  Remove the gear plastic
 > from its steel hub by hacksawing 2 or more diagonal cuts thru the plastic to
 > the hub, pry or chew off the pieces.
 > 2.  Note that both ends of the groove pin are swaged larger than the pin
 > center dia.  Saw off the smaller pin end and file it flush with 
the gear hub.
 > 3.  Support the gear hub and shaft in a suitable V block or vice jaws and
 > drive out the pin using a 5/32" dia pin punch or an old nail on 
the filed end.
 > 4.  Remove the gear hub and retain the shim washer pack for reassembly.
 > 5.  Remove the shaft, not loosing the fiber thrust washer at the 
top end, and
 > clean the dist body and Hall rotor.  If there is any oil in the distributor,
 > service the crankcase breather system.  (This distributor does not 
use a shaft
 > seal component, just a reverse spiral groove on the shaft in the top portion
 > of the upper bushing.)
 > III.  New Bronze Gear Installation:
 > 1.  Install the original shim pack on the shaft, followed by the new gear.
 > align the smaller gear pin hole with the shaft pin hole.  (Do not use the
 > larger pin hole, it is a vendor goof.)  Support the gear hub on the far side
 > (not on the gear teeth) and tap the roll pin part way into the shaft.  Check
 > the dist shaft axial clearance.  It must not be tight, but should 
have 2 to 5
 > thou end play, a "just perceptable free movement" feel without binding.  If
 > not so, remove the gear and adjust the shim pack, + or -, as required.  An
 > additional .003" thick shim is provided with the gear and roll pin to
 > faciliate this adjustment.  Add or subtract different thickness shims until
 > the end play is the closest to the "feel" spec.  Unlikely, but if more or
 > different thickness shims are necessary, they can be cut from 
paper and added
 > into the center of the shim pack.
 > 2.  Drive the roll pin thru the assembly and center it in the gear.  Recheck
 > the axial clearance "feel".
 > IV.  Distributor Installation:  without VAG alignment tools.
 > 1.  Remove the black plastic shield which may have been covering and
 > seperating the Hall area of the dist. body from the rotor.  Not all 20V dist
 > have this shield, which may be replaced just prior to reinstalling the dist
 > cap.
 > 2.  Notice that there is a line embossed on the top surface of the 
Hall rotor
 > immediately under the hot end of the dist rotor, and a mating line notched
 > into the top edge of the distributor housing opposite the Hall connector and
 > just above the Hall sensor unit.  When finally in place and locked 
down these
 > two lines must line up with each other with the engine at TDC.
 > 3.  With the dist and rotor lined up about as it was as you removed it (you
 > forgot where that was, didn't you?) insert the dist, moving the rotor as
 > necessary to get the gears to mesh.  Once all the way seated in 
place,  while
 > applying a slight counterclockwise finger bias to the rotor (thus 
 > gear mesh clearance), adjust/rotate the dist body to exactly line up the two
 > marks, and lock it down (lightly, you may have to move it again) with the
 > clamp and nut.  If you are not happy with the resultant orientation angle of
 > the Hall connector, pull the dist just enough to free the gears 
and rotate the
 > rotor one gear tooth in the same direction that you would like to move the
 > Hall connector when the two marks are again lined up.  The distributor will
 > work in any oriention, as long as the two lines are lined up at TDC, the
 > actual oriention just facilitates the electrical connections to the Hall and
 > dist cap.
 > 4.  All 200 owners who elected to short cut and not remove the 
intake manifold
 > per Bentley, must now curse loudly at the Audi gods for the 
inaccessability of
 > the whole dist system and the dist cap hold down clamps in particular.  7A
 > owners need not comply.
 > 5.  "Reinstall all components in reverse order of removal".  More 
of Bentley's
 > sage advice.  If the engine won't start, recheck your TDC position for
 > accuracy and then the distributor marks alignment for its 
accuracy.  They must
 > be right on.  Do not attempt to move the dist with the engine running as you
 > did with those old point type dist, as this dist does not determine engine
 > ignition timing.  Thank you for flying united.
 > E-mail if you have any serious problems with your installation or with these
 > instructions.
 > Bernie

At 09:27 PM 6/7/2006, you wrote:
>Well I got bit by the 3B plastic distributor gear problem today.  I was
>wondering if anybody had replaced this themselves, and if so is there a
>writeup on it anywhere?  ALso, if anybody has a spare 3B distributor laying
>around with the metal gear that they want to part with I would be
>interested.  Thanks!
>S-CAR-List mailing list
>S-CAR-List at audifans.com

-Peter Schulz
Chelmsford Ma, USA

1991 200 20v Q Avant Titan Grey
1991 200 20v Q Avant Indigo Mica
1991 90 20v Q Red

1990 CQ silver (awaiting S2 engine transplant)
1991 CQ silver  (potentially replacing the 1990 for  the transplant)
1990 CQ red ( to part or not)

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