Crankshaft snout bolt

[wipeout]

Hello,

Could anybody tell me the correct size of the bolt for the pulley and harmonic balancer. I dont mean the littel ones that connect to the harmonic but the center bolt that connects to the crank.

I got these specs from a chevy dealer 7/16-20x 2-1/4" but it is a aftermarket bolt and dont know if it is the correct size.

I lost the original bolt and washer somewhere. :ugh

Thanks for your help. Again.

 

[pws69]

Hello,

Could anybody tell me the correct size of the bolt for the pulley and harmonic balancer. I dont mean the littel ones that connect to the harmonic but the center bolt that connects to the crank.

I got these specs from a chevy dealer 7/16-20x 2-1/4" but it is a aftermarket bolt and dont know if it is the correct size.

I lost the original bolt and washer somewhere. :ugh

Thanks for your help. Again.

Call your local NAPA - they should have one with the correct washer (which is important). Last one I got was from Summit - with washer also.

 

[Dave L.]

GM# 3815933 7/16-20 x 2-1/4 (fine thread) bolt
the washer is GM# 14001829.

 

[wipeout]

Thanks guys ordered the bolt. Wont be in till next week. :eyerole

 

[JohnZ]

Thanks guys ordered the bolt. Wont be in till next week. :eyerole

Make sure you use a lock washer and the correct extra-thick special flat washer with it.

 

[glen242]

Don't use the bolt to pull the balancer on to the crank. Buy/rent/borrow an installation tool.

 

[wipeout]

Why is it a bad idea to use a longer bolt to install the harmonic. would it damage the threads in the snout?

 

[geekinavette]

Why is it a bad idea to use a longer bolt to install the harmonic. would it damage the threads in the snout?

In a word...yes. When the balancer is just sitting on the end of the crank you'll only get a few threads of engagement...very easy to strip those threads out in the crank snout. Use an installation tool. DO NOT hammer on the balancer!

The big thick washer is important too. It's not just a flat washer, it's a "crush" washer...has a curve to it...make sure that goes on the right direction. A lock washer is completely unnecessary...the crush washer does that job.

Bill