Bell Housing ball stud

[John M.]

We have a reproduction 621 bell housing and a repro ball stud that don't want to go together. Rather than force it I decided to check the threads and get a tap to match. The ball stud, male thread, measures about .805" and it's 16 threads/inch, which would indicate 13/16-16. My engineering handbook only lists 13/16-20 which is extra fine.
What is the stock thread for this part? It's a 67.
Thanks,
John McRae

[Joe L.]

Re: Bell Housing ball stud

We have a reproduction 621 bell housing and a repro ball stud that don't want to go together. Rather than force it I decided to check the threads and get a tap to match. The ball stud, male thread, measures about .805" and it's 16 threads/inch, which would indicate 13/16-16. My engineering handbook only lists 13/16-20 which is extra fine.
What is the stock thread for this part? It's a 67.
Thanks,
John McRae

John-----


The thread size for ALL 1955-81 Corvette ball studs is 13/16-16.

[John M.]

Re: Bell Housing ball stud

Thanks a lot Joe,
John

[David L.]

Re: Bell Housing ball stud

According to my vintage Chev. parts catalogs there were two different clutch fork ball studs used from 1955 to 1981.

GM # 3792000 (1 1/2" long) described as "13/16-16 stud w/21/32 dia. ball'
1955-1965 Corvette
1975 (2nd design)
1976-1981

GM # 3887159 (1 3/8" long)
1966-1974
1975 1st design

Dave

[Joe L.]

Re: Bell Housing ball stud

According to my vintage Chev. parts catalogs there were two different clutch fork ball studs used from 1955 to 1981.

GM # 3792000 (1 1/2" long) described as "13/16-16 stud w/21/32 dia. ball'
1955-1965 Corvette
1975 (2nd design)
1976-1981

GM # 3887159 (1 3/8" long)
1966-1974
1975 1st design

Dave

Dave------


The GM #3887159 was discontinued in May, 1996 and replaced by the GM #3792000. I know of no source for a ball stud equivalent to the 3887159, aftermarket or otherwise. I beleive that the 3887159 was, basically, an "experiment" to deal with clutch linkage problems experienced on Corvettes. I don't think it really worked out and that's why GM went back to the 3792000 during the 1975 model year. There was no other difference in the 68 to E75 clutch system compared to the L75-81 system.

Since May, 1996, the GM #3792000 has been the ball stud available in SERVICE for all 1955-81 Corvette applications.