[s-cars] Bullet Dodging - revisited

[Robert Myers]

Earlier:

The pulley came out nicely and exposed the fact that the key which locks 
the pulley has been nearly completely sheared off.  A light touch pulling 
on the key with a finger tip broke it off into my hands.  There couldn't 
have been more than 0.01 mm of metal holding the key in 
place.  Additionally, there is evidence of some rubbing of the pulley 
against its seat on the crank.  It has been shifting its position 
(rotationally) by nearly the width of the key (or about 1.5 
belt  teeth).  This is more than enough to have an effect on the timing.

If that key had completely sheared off it would have had the effect of a 
broken belt.  The condition it was in has me wondering if I'd have even 
made it home.  A new pulley is ordered and will be here tomorrow.

Resolution (Next Day):

The new pulley arrived and went in.  Careful inspection reveals that the 
rather massive ~330 ft-lbs torque of the crank bolt plays virtually no role 
at all in holding the pulley's rotational location.  In essence the pulley 
is free floating within (some rather precisely defined) limits.  By design 
the only thing keeping the pulley from freely rotating WRT the crank is 
that quite shearable key.

As John Tilden suggests, my future timing belt maintenance routine will 
include replacing the crank pulley.

Recommendation:

I'd suggest that replacing this pulley should probably also be included in 
your next TB replacement.


Bob
Http://Chips-Ur-S.com