[s-cars] Bullet Dodging
davidpriebe at cablespeed.com
Wed Jun 8 18:27:41 EDT 2005
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
>> (rotationally) by nearly the width of the key (or about
>> 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
> My Mechanic has found several instances of failed or
>near failing Crank
> Pulley Keys!
> One which was "glued" back together with epoxy by a
> Pulley, Bolt, Crank and remnants of the key! Imagine the
> 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
> 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
> 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
> 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
> S-CAR-List mailing list
> S-CAR-List at audifans.com
95.5 S6 122k (hers)
66 MGB 41k
77 Porsche 911
91 200tqa 185k gone but not forgotten
More information about the S-CAR-List