[s-cars] Bullet Dodging

[David Priebe]

It sounds like you are describing what my mechanic found 
when he did my timing belt last fall. Epoxy was used to 
glue the pulley back to the crank w/o the key. And now I 
have some very expensive bent valve paper weights on my 
desk as a result of some very sloppy previous 
mechanic/dealer. I'm still baffled that the previous 
mechanic didn't replace the key, but instead epoxyied the 
pulley on. Sounds like more work using the epoxy than 
using a new key. The array of broken Snap-On breaker bars 
that it took to get the bolt loosened was very impressive!


On Wed, 8 Jun 2005 15:19:30 -0700
  "John Tilden" <j.n.tilden at comcast.net> wrote:
> Bob Writes:
>> While removing the belt - "Hmmmm - the toothed belt 
>>pulley is a bit loose
>> on the end of the crank shaft - let's pull that sucker 
>>out of there and
>> have a look at it."
>>
>> 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.
> 
> My Mechanic has found several instances of failed or 
>near failing Crank
> Pulley Keys!
> One which was "glued" back together with epoxy by a 
>previous mechanic!
> Pulley, Bolt, Crank and remnants of the key! Imagine the 
>expletives that
> were used to get that apart! He broke two 1/2" drive 
>Snap-On Breaker Bars
> getting the Bolt out! Finally bought a 3/4" drive 
>breaker and socket to get
> it apart!
> I am going to make a practice of replacing my Crank 
>Pulley every time the
> timing belt is replaced!
> The "Key" is an integral part of the Pulley which is 
>manufactured using
> Powdered Metal Technology, basically pressed and 
>sintered powdered iron.
> This technology is great in compression and in large 
>sections, but the key
> is pretty thin and has some notchy geometry which will 
>tend to propagate
> cracks, so out with the old and in with a new one! The 
>good news is they are
> "only" about $45.00 so not a big cost item.
> Just add this to the other parts you replace "when you 
>are in there"!
> Timing Belt, Water Pump, Timing Belt Tensioner, Serp 
>Belt, Serp. Belt
> Tensioner, Cam Position Sensor, etc, What did I miss?
> 
> By the way, connecting rods on a number of new 
>automobiles are made using PM
> technology!
> As I recall, even the new Water cooled Porsche rods! 
>please correct me if I
> am in error!
> They are even proud of the fact that they "Crack" them 
>into two pieces after
> the big end is machined to diameter, maybe OK for a 
>Honda, but....!
> 
> John
> 
> John Tilden
> Tilden Consulting Services
> 2820 164th Ave N.E.
> Bellevue WA 98008
> (425) 881-2895 Office
> (206) 240-5318 Mobile
> j.n.tilden at comcast.net
> 
> 
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David Priebe
Carnation, WA
95.5 S6 122k (hers)
66 MGB 41k
77 Porsche 911
91 200tqa 185k gone but not forgotten