1969 pulley and balancer assemblies

[Joe T.]

Hi Guys: My AIM calls for a "special washer" GM3914674 on the pulley to harmonic balancer bolts in addition to what appears to be a conventional split lock washer. What is "special" about this washer? Is it still available or superceded?? Also, What bolt holds the pulley to the balancer? I have 3/8x16 bolts that fit, but I am wondering about the length and grade as well as the head markings? Plated or phospate? I have other related questions, but I'll save those for another post.
Many thanks and regards...Joe

[Joe L.]

Re: 1969 pulley and balancer assemblies

Joe----

The GM #3914674 washer you mention was so special that you could never even buy it from GM in SERVICE. However, I believe that the "special feature" of this washer was that it was extra thick at about 1/8". Otherwise, it was a standard flat washer for 3/8" bolt size. I don't think that it's reproduced, but you might be able to find such a washer from a source like McMaster-Carr (or, use 2 1/16" thick standard washers).

The 3 bolts retaining the pulley to the balancer were 3/8-16 X 1-1/4". They were a non-indented head, GM 280M bolt (3 lines) and I believe they were zinc plated. I don't know the usual headmarks.

[Joe T.]

Re: 1969 pulley and balancer assemblies

Thanks Joe.
I have two of those washers in my parts box as well as those bolts, and didn't know where they went, so I'll just find a third. Would you have any idea why they were double thickness? Thanks again. This project is moving along albeit SLOWLY...put it together...take it apart;...put it together...take it apart;...put it.... and so on ....

[Joe L.]

Re: 1969 pulley and balancer assemblies

Joe-----

I've no idea, whatsoever, for these, particular, washers. However, there are lots of "enigmas" in automotive construction.