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Crank pulley bolt thread size??


jatchis
07-11-2010, 02:10 PM
Need a little help. 2000 Grand Prix GTP (Daytona pace car edition).

I had the classic crank position sensor symptoms, so set out to change it today. After pulling the vibration dampner, I replaced the sensor without a hitch. I started re-assembling, and found that the puller I used had boogered up the outer 1 or 2 threads of the bolt hole (in the end of the crank) that holds the dampner on.

Before I take a rotory file to the threads to try and clear the bad thread(s), I thought I might try running a tap in there to clean them up.

Does anyone know what thread size that bolt is so I can make sure I get the right tap?

Any help or advice would be greatly appreciated .....

richtazz
07-12-2010, 10:59 AM
3/4"x16 thread

jatchis
07-12-2010, 02:03 PM
3/4"x16 thread


Really??

Wow, I thought it was a metric thread. We may actually have that size up at the shop.

richtazz
07-13-2010, 02:12 PM
that's what the GM computer shows. I figured it would be metric as well.

jakegday
07-13-2010, 06:38 PM
according to the second post in this thread, they are metric bolts

http://www.grandprixforums.net/f95/any-advice-removing-old-harmonic-balancer-13775.html

tblake
07-14-2010, 08:06 PM
Are we talking bolts you thread into the crank pulley to pull it off, or are you actually asking about the actual crank bolt in the center of the crank?

jatchis
07-17-2010, 06:48 AM
Are we talking bolts you thread into the crank pulley to pull it off, or are you actually asking about the actual crank bolt in the center of the crank?

The center bolt, that holds the pulley to the crank. The outer thread got messed up.

I went up to the race car shop, we have a tap/die set that includes 3/4-16, and that size die threads onto the crank bolt, so I will be trying to clean things up with the 3/4-16 tap after I finish my coffee this morning ...

jatchis
07-17-2010, 11:17 AM
Happy to report that I got her on the road again.

Thanks guys!!

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