Harmonic Balancer Threaded Holes

[93SHO_2]

What is the size of the 2 threaded holes in the harmonic balancer? I tried 7mm, 8mm with 1.00 and 1.25 threads distance and 5/16 with 18 pitch and 24 pitch, nothing seemed to fit.

I drilled them to 5/16 then tapped them to 24 threads per inch, used two 2 inch length bolts and had plenty of clearance, but I don't think I should of had to go thru all that.

 

[AutoSHO]

The intake manifold bolts (I think) thread right in.

 

[sdpatt]

They are M8, coarse thread and that size bolt usually comes with any damper puller kit.

Edit: Thanks Gary, I was going from memory and was mistaken.

<small>[ November 12, 2003, 12:24 PM: Message edited by: sdpatt ]</small>

 

[gmorrell]

sdpatt:
They are M10, coarse thread and that size bolt usually comes with any damper puller kit.

Uhhh, no, they're not 10mm. They're M8-1.25. The threads in the damper were probably a bit dirty/corroded and needed chased with a tap.

And just because I'm an ****-retentive, picky SOB, its not a harmonic balancer, its a harmonic damper. The Yamaha's rotating assembly is by nature, zero-balance, and doesn't require any additional balancing.

 

[twr]

Of course there is no need to verify, but there are indeed M8-1.25. I had to buy some to pull the damper when I did my engine upgrade. Nice to see you posting here Gary.

<small>[ November 13, 2003, 11:20 AM: Message edited by: twr ]</small>

 

[93SHO_2]

Thanbks for the clarity, it is a balancer on my 68 302 J code, when did things change? wink

I'll include the bolts if I ever sell the car.

 

[V6Hova]

I had the same thing happen to me. I tried metric (fine and coarse) and standard but nothing would work. After about 3 hours of trips to the hardware i was messing with it when I noticed it move. I pulled the damn thing off with my fingers. Anyway the threads were messed up from the person before me. I just retapped them from the back. But i almost did the same thing as you (drill and retap).