Thread Pitch

[Peter Golledge]

> OK, my bad. Rereading my original post, I don't think I clearly asked the
> question. 
> 
> 1. What is the standard Audi Thread Pitch (if any)?

Several different pitches get used, I can pull the old bolts out and gauge
them when I get home...  But the Family A  has the pitch in there, check out 
N 0101161 in A20Q year:89  MG:4  SG:12  Illustration 40-00, the remarks indicate:

M12x1,5x28

Translation 12mm dia, 1.5 pitch, 28 mm length.  No mention of grade though in 
the FA, see below.

> 2. What would the difference be using a 1.0 vs. a 1.25 (other than increased
> wear on my wrist from more revolutions)?

On the subframe bolts you have to get it right (capture nuts in the body),
same with sway bar bolts.  Given thread pitch affects the torque used
to tighten correctly (and ultimately the strength of bolt+nut) I would 
stick with the original bolts.

A local metric bolt supply should have everything in stock for around $10.  Check
(and double check) the grade, subframes bolts are 10.9 and some other suspension
nuts/bolts are as well.  Since the grade is marked on the head in most cases
you can verify grade before tearing things apart.

Cheers
-- 
Peter Golledge