[s-cars] No Start ABY/AAN engine - Problem Found?

[Ben Swann]

I did confirm that there is no need to drill through the hardened pin  - the number of
teeth from TDC would be 12 instead of the 14th where the pin is.  The hole if drilled
properly would go through an existing hole in the pressure plate.  So all I need to
drill through is the thickness of the flywheel and have the location spot on.

Still the bellhousing idea sounds attractive and at first thought seems easier.  The
problems would be to findthe exact location as well as deal with an irregular surface -
the correct spot may in fact go through one of the bellhousing bolts and then would not
be an option.  Then one needs to precisely locate the sensor so it flys just above the
pin without crashing into it and make a retainer to affix it permanently.  I had my
hopes up at first that the existing factory hole in the transmission bellhousing or the
01E was made for this purpose, but no such luck.

Another concept would be to incorporate a timer circuit to count teeth after the
detection of the pin using that hole and generate a second signal to the ECU which
corresponds to the correct location.  Devil's in the details.

I will probably try the flywheel as it is straightforward and with correct measurement
and equipment, I should be able to do this the same as if I were doing it on a bench.

Ben

-----Original Message-----
From: JC [mailto:jc at j2c3.com] 
Sent: Sunday, October 03, 2010 10:28 AM
To: 'Ben Swann'; qshipq at aol.com; cody at 5000tq.com
Cc: s-car-list at audifans.com; chris.miller at bqconsultants.com
Subject: RE: [s-cars] No Start ABY/AAN engine - Problem Found?

>
> So..I am considering another alternative -  a backup plan to the 
> flywheel drilling in situ.  This is to simply drill a hole through the 
> trans bell-housing at the precise spot where

FWIW I like this plan much better from a FMEA point of view.  Worst case if there are
problems with the flywheel drilling project, you could be looking at junking the
flywheel and there you are dropping the tranny anyway. And with all respect to the fact
that someone has done it before, drilling in-situ through the hardened pin, getting
location exactly right, all just sounds like a mess with multiple ways to have things go
wrong.

Drilling the bellhousing for a new sensor location on the other hand has far lower
'worst case' implications. Mounting doesn't work out or it's wrong spot, meh you've got
another small hole in your bellhousing. Fill it with some of that extra epoxy you've got
lying around.  Other thing that occurs to me if doing this option would be to fab a
mount for the sensor that allows depth adjustment to get that critical spacing you
talked about correct. Use locktite and a locknut to affix it once you've got it perfect.

All that said, I've learned the painful way that often it's far better to suck up taking
more things apart and out of the way than screw around for hours/days with a work around
to avoid doing it.

Are you sure all this isn't more trouble than just dropping that tranny one more time
and getting it all back together the "right" way forever?

---- current ----
1995.5 S6 Avant
2003 E46 M3 Cic
2008 A3 2.0tDSG
---- past lives ----
2006 A4 2.0TQA
1998 A6Q 2.8 PES G2
1989 200TQA SJM
1990 CQ
1997 A4 1.8TQ Wett
1987 4kCSQ

John J. Cunningham
jc at j2c3.com
US Mobile +1 (617) 750-5025
China Mobile: +86 (0) 136 8175 8180



__________ Information from ESET NOD32 Antivirus, version of virus signature database
5499 (20101003) __________

The message was checked by ESET NOD32 Antivirus.

http://www.eset.com