1969 Clutch Fan

[Stephen B.]

I've noticed that clutch fans come in two different sizes. I have a Sweitzer Clutch dated 1969 with a hub too large to fit in the 5 blade fan from the era. Can anybody shed any light on the subject?

[Jack H.]

Re: 1969 Clutch Fan

Easy, this is a well known issue. The change happened in 1971.

Cars built before that had a fan clutch with small hub with small bolt pattern while '71 and later cars used a big hub with wide bolt pattern. Fan clutch HAS to agree with both the water pump drive hub AND the geometry of the fan it's mounted to...

[Joe L.]

Re: 1969 Clutch Fan

Easy, this is a well known issue. The change happened in 1971.

Cars built before that had a fan clutch with small hub with small bolt pattern while '71 and later cars used a big hub with wide bolt pattern. Fan clutch HAS to agree with both the water pump drive hub AND the geometry of the fan it's mounted to...

Jack and Stephen------


There were also fan clutches that used the large (3-1/4" bolt circle) bolt pattern for the fan attachment and the small (1-3/4" bolt circle) bolt pattern for the hub attachment. These were used on some late 60's Chevrolet vehicles, but never Corvettes.

[Stephen B.]

Re: 1969 Clutch Fan

Thanks for the information.

[Grahame M.]

Re: 1969 Clutch Fan

Thank you so much for the information.
cheers
Grahame