1970 Fan Clutch configuration

[William H.]

For a 1970 350/350 built March 12, I removed the original fan clutch (dated 12 19 69) from the fan and it used bolts with lock washers (stamped A) for attachment (not studs). The engine was assembled Feb 10th. The Judging Guide says there should be studs with nuts to attach the fan. It was evident to me the fan and clutch had never been separated on this very original car. Has anyone seen this configuration?

[Joe L.]

Re: 1970 Fan Clutch configuration

For a 1970 350/350 built March 12, I removed the original fan clutch (dated 12 19 69) from the fan and it used bolts with lock washers (stamped A) for attachment (not studs). The engine was assembled Feb 10th. The Judging Guide says there should be studs with nuts to attach the fan. It was evident to me the fan and clutch had never been separated on this very original car. Has anyone seen this configuration?

Bill-------


Some fan clutches used bolts for attachment to the fan and some used studs which were an integral part of/supplied with the fan clutch. For example, the GM #3916139 fan clutch used with some base engine 1970's used integral studs with lockwashers/nuts. However, your application used the GM #3937771 fan clutch. This fan clutch did not have integral/supplied with studs. So, bolts were used. I'd be amazed if lockwashers were not used in conjunction with these bolts although they could have been the captured-type lockwashers.

[William H.]

Re: 1970 Fan Clutch configuration

Thanks, Joe. Much appreciated.

[William H.]

Re: 1970 Fan Clutch configuration

Can someone help with assessing the finish of the fan clutch hardware? Looks like possibly a grey phosphate finish? Thanks for your expertise.

001.jpgCleaned Hardware.jpg

[Joe L.]

Re: 1970 Fan Clutch configuration

Can someone help with assessing the finish of the fan clutch hardware? Looks like possibly a grey phosphate finish? Thanks for your expertise.

[ATTACH=CONFIG]60282[/ATTACH][ATTACH=CONFIG]60283[/ATTACH]

Bill-------


It looks correct to me. The bolt was GM #9419030 and the lockwasher was GM #187119. The bolt was once available from GM in SERVICE but was discontinued in 1980. The lockwasher was never available in SERVICE. Both were phosphate finished.

[Mike E.]

Re: 1970 Fan Clutch configuration

Bill,
These pics are from 1970 #6243. I bought it from the original owner a year ago. Still has original hoses and clamps, one of the two original belts, etc. Trim tag on the car is March 15. 60k miles L46. Clutch on fan is dated 2 16 70 SC. Looks to me like you are on to something. Timing is good--we're working on the 70-72 manual now.
P4110033.jpgP4110034.jpg

[Jim T.]

Re: 1970 Fan Clutch configuration

Mike, I just looked at my original owner 1970 350/300 with air conditioning built in July 1970. It has the same type bolt and bolt ID with washer attaching the original fan to the original fan clutch.

[Mike E.]

Re: 1970 Fan Clutch configuration

Thanks, Jim.

[Terry M.]

Re: 1970 Fan Clutch configuration

1970 #2161, A29, Fan bolts to clutch. LT1