I need a new Fan clutch 1967 427/400 AC car

[John M.]

anyone buy one recently? Darn thing failed today, it now free spins and wobbles. thanks

[Joe M.]

Re: I need a new Fan clutch 1967 427/400 AC car

For $200-$295, there are a couple of gentlemen that will rebuild it.

[John M.]

Re: I need a new Fan clutch 1967 427/400 AC car

GM 3857531,3916146 Can someone tell me what is the correct part number for my fan clutch. The car is a 427/400HP powerglide AC car. apparently I own both types and the 3916146 was the one that failed however I have a 3857531 I think? I can't locate a part number on it but have found identical one's online. The ones I saw on line are also for a 427.

[John M.]

Re: I need a new Fan clutch 1967 427/400 AC car

Ebay and every site I research shows both types as BB fan clutch. Looks like one type is just a older model??

[Joe M.]

Re: I need a new Fan clutch 1967 427/400 AC car

GM Parts & Accessory Catalog 14 indicates that the 387531 is for 66-67 with 427. I could not find the other fan clutch part number.

[Joe L.]

Re: I need a new Fan clutch 1967 427/400 AC car

GM 3857531,3916146 Can someone tell me what is the correct part number for my fan clutch. The car is a 427/400HP powerglide AC car. apparently I own both types and the 3916146 was the one that failed however I have a 3857531 I think? I can't locate a part number on it but have found identical one's online. The ones I saw on line are also for a 427.

John------


GM #3857531 was the original fan clutch. It was discontinued in September, 1981 and replaced by GM #3916141. Available for many years, unfortunately, the latter has now also been discontinued. The 391641 was the most correct fan clutch for your car available anywhere.

I do not recommend the use of rebuilt fan clutches for driven cars. If judging is a primary concern, they are fine.

[John M.]

Re: I need a new Fan clutch 1967 427/400 AC car

Thats what I thought, when I bought this car it was in boxes and one box had a seven blade fan and the #3857531 clutch attached to it. So the 3857531 should work and still be correct if it is good? It does show signs of still being good.

[David L.]

Re: I need a new Fan clutch 1967 427/400 AC car

Thats what I thought, when I bought this car it was in boxes and one box had a seven blade fan and the #3857531 clutch attached to it. So the 3857531 should work and still be correct if it is good? It does show signs of still being good.

John,

I noticed you mentioned a 7-blade fan. As far as I know the only 7-blade fan used on any mid-year Corvette was fan # 3853943 on the 1964-1965 Corvettes w/327 & AC. The 1966-1967 Corvettes w/327 & AC used a 5-blade fan, 18" dia. (GM # 3789562 or 3863137). The 1966-1967 Corvettes w/427 used a 5-blade fan, 17 1/2" dia. (GM # 3888366). I have never found anything about what fan was used on a 1966 or 1967 Corvette w/427 & AC. I always assume it was the 3888366 5-blade fan stamped "66".
Can you describe your 7-blade fan or post a photo? Are there any stampings on it?

Dave

[John M.]

Re: I need a new Fan clutch 1967 427/400 AC car

Dave I have both a 5 blade and a seven, the seven was sitting on my parts shelve not in use. It had the other fan clutch attached to it, I'm not sure what or how the previous owner was doing with it. I'm going to install the other clutch (GM #3857531) tonight see how the car runs. The way I understand it it was the original fan clutch for BB prior to the Eaton model.

If anyone knows a member looking for a seven blade fan I'll be willing to part with it. I'll get the part # tonight and post it.

[David L.]

Re: I need a new Fan clutch 1967 427/400 AC car

John,

I assume your 5-blade fan is 17 1/2" in dia. and stamped "H" and "66".

Instead of using my original 5-blade 17 1/8" fan (GM # 3770529) on my 1966 Corvette w/327 (wo/AC) I use a 1968 Chevrolet w/AC 7-blade 18" fan (alum. blades), GM # 3931002.

Dave

[John M.]

Re: I need a new Fan clutch 1967 427/400 AC car

This is the one I have that is still good, I think these are the original clutches?????? My Eaton one is the failed unit. I hoping this will work on the car and still be within original equipment.

[Jack H.]

Re: I need a new Fan clutch 1967 427/400 AC car

That one has the appearance of a '62 Corvette SB Schwitzer clutch. But, there were other uses of similar appearing Schwitzer fan clutches like on '65 Olds. Your copy of the 1967 Judging Guide will tell you there were four fan clutches used in '67: Schwitzer or Eaton small block and Schwitzer or Eaton big block. Schwitzer clutches used the bar actuator like the picture you show, while Eaton units used a bi-metal coil actuator.

The difference between SB and BB clutches lies in the length of the shaft which moved the fan fore vs. aft to compensate for the difference in the length of the SB vs. BB engine. Specific measurements are cited in the JG book. So, you don't have to guess. Crack open your copy of the book and you'll see...

[David L.]

Re: I need a new Fan clutch 1967 427/400 AC car

John,

According to my research the "CJ" fan clutch is GM # 3916139 used on 1967 small blocks. The distance from the fan mounting surface to the W/P hub mounting surface should measure about 1.8".

The 66-67 427 fan-clutch is GM # 3857531 (ink stamped "CT") and has a shorter shaft. My 1967 Chev. Parts Catalog (Apr. 1967) also lists GM # 3857530 as the part number for the 66-67 Corvette 427 fan clutch (described as "thermo. control (2 53/64 O.L.).
My research is based on 30+ year of experience, physical evidence, and the used of over 50 vintage Chevrolet parts catalog, Chevrolet Parts History catalogs, many assembly manuals, and other vintage Chevrolet documentation. I have never even seen a judging guide.

Enclosed are two photos of an Eaton "CJ" fan clutch (dated "L27G" or Nov. 27, 1966) that I bought with a 3863137 (stamped "912239") 5-blade 18" fan dated "L6" (Nov. 1966) used on an early 1967 model w/AC.

https://www.forums.ncrs.org/showthre...t=eaton+clutch

Dave