Fan clutch

[Chris C.]

I am looking to install a more correct fan clutch on my 1967 435hp. I am curious who offers the most correct looking and correct functioning fan clutch. Thanks for any input.

Chris

[Donald A.]

Re: Fan clutch

Hi Chris - at recent judging my 67 L71 fan clutch was deducted as NTP although an Eaton clutch with CK stamping. On researching this found the configuration of the shaft and body of the clutch were different than original, other small changes as well. A vendor offers fan clutch restoration services and has a stock of original units www.corvettestop.com with contact info Tim 530-677-4270. These are not cheap but I can confirm they do a good job of proper restoration. They are also on eBay you can view one of their auctions here http://www.ebay.com/itm/Original-Res...ab139c&vxp=mtr and they will also date code if you request (JG says not all were date coded). They also restore original Schwitzer units. I'm sure there are many other vendors that do this, I can just report that this company did a good job for me!

[Ara G.]

Re: Fan clutch

Chris, you will get a lot of posts on this one - but suffice to say i am not aware (and i may be wrong) of any supplier that makes a "correct" clutch. I would find a core and have it restored and rebuilt. Some great guys out there do fantastic work on restoring them. Cores are cheap. Either a Schwitzer (they are dated) or an Eaton will work for your car (shaft length being correct for a BB). Vinnie did my last one, and it came great. Fred does great work, as does Kirkonnel (never used him, but hear he does nice work - i think SB told me that). The elephant ears on the replacement Eatons are not shaped correctly (oblonged as opposed to square) and i don't think they're repopping the Schwitzers. Good luck. ARA

[Ken A.]

Re: Fan clutch

Check with any of the catalogue companies for a repop Schwitzer, either version.

[Larry M.]

Re: Fan clutch

Chris, you will get a lot of posts on this one - but suffice to say i am not aware (and i may be wrong) of any supplier that makes a "correct" clutch. I would find a core and have it restored and rebuilt. Some great guys out there do fantastic work on restoring them. Cores are cheap. Either a Schwitzer (they are dated) or an Eaton will work for your car (shaft length being correct for a BB). Vinnie did my last one, and it came great. Fred does great work, as does Kirkonnel (never used him, but hear he does nice work - i think SB told me that). The elephant ears on the replacement Eatons are not shaped correctly (oblonged as opposed to square) and i don't think they're repopping the Schwitzers. Good luck. ARA

[Ken A.]

Re: Fan clutch

Larry et al,
K & B Makes the C-2 fan clutch currently being sold by LIC & most other vendors. Other than looking "new" it is functionally & cosmetically correct.
Ken

[David L.]

Re: Fan clutch

I found this NORS 3916141 "CK" fan clutch at the Rhinebeck, NY, swap meet 12 days ago for $25. It's not exactly the correct style and part number but the price was right. The GM box is dated August 1994. The fan clutch is stamped "EATON" and ink stamped "CK" and "J27E2" (some kind of date code).

GM # 3857530 is listed for 1966-1967 Corvette w/427 and 1965-1966 Chevrolets w/396,409,427 in my April 1967 Chevrolet Parts Catalog. GM # 3857530 was replaced with GM # 3916141 in Jan. 1968. My July 1967 Chevrolet Parts Catalog lists GM #3857530 for 1965-1966 Chevrolets w/396,409,427.

My July 1967 Chevrolet Parts Catalog lists GM # 3857531 for the 1966-1967 Corvette w/427. GM # 3857531 is a Schweitzer fan clutch stamped "CT". GM # 3857531 was also replaced with GM # 3916141.

The 3916141 fan clutch is listed for the 1967 Chevrolets w/396 & 427.

Dave

[Mark D.]

Re: Fan clutch

Reproduction bar type clutches will not have patent numbers on the face and, this is easily checked during judging.

[Joe L.]

Re: Fan clutch

I found this NORS 3916141 "CK" fan clutch at the Rhinebeck, NY, swap meet 12 days ago for $25. It's not exactly the correct style and part number but the price was right. The GM box is dated August 1994. The fan clutch is stamped "EATON" and ink stamped "CK" and "J27E2" (some kind of date code).

GM # 3857530 is listed for 1966-1967 Corvette w/427 and 1965-1966 Chevrolets w/396,409,427 in my April 1967 Chevrolet Parts Catalog. GM # 3857530 was replaced with GM # 3916141 in Jan. 1968. My July 1967 Chevrolet Parts Catalog lists GM #3857530 for 1965-1966 Chevrolets w/396,409,427.

My July 1967 Chevrolet Parts Catalog lists GM # 3857531 for the 1966-1967 Corvette w/427. GM # 3857531 is a Schweitzer fan clutch stamped "CT". GM # 3857531 was also replaced with GM # 3916141.

The 3916141 fan clutch is listed for the 1967 Chevrolets w/396 & 427.

Dave

Dave-------


The GM #3916141 clutch was used in PRODUCTION for some 1968-69 Corvette big blocks. It eventually became SERVICE for virtually all 1960-70 Corvettes. The original 3916141 differed slightly in configuration from the later ones such as the one pictured.

[Tony S.]

Re: Fan clutch

The fan clutch presents a real challenge for flight judging. Finding and using an original can be tough because so many originals have lost their oil or still have oil but leak. You find out the hard way if the fan clutch leaks because when you turn on your engine, you get an oil spray inside your engine compartment and underneath side of your hood. You can send off a fan clutch for restoration, but the finished results can be inconsistent depending on who did the restoration. I have personally examined both the AFC and LI fan clutches that are being sold. The good news is they seem to be well made and don't spray oil. The bad news is that they don't tend to do well for judging. If you install a fan clutch straight out of the box from either vendor, you'll probably get a 3 point deduction (out of 5 originality points) for either because there are issues with configuration, finish and date.

I found the one on my car for judging in a dirty pile of fan clutches at Bloomington last year. It cleaned up and still holds oil. However, after nationals in Overland Park last year, I removed my fan clutch and installed a fan clutch eliminator. It helps keep the engine cooler and I don't have to worry about oil spraying.

[David L.]

Re: Fan clutch

Dave-------


The GM #3916141 clutch was used in PRODUCTION for some 1968-69 Corvette big blocks. It eventually became SERVICE for virtually all 1960-70 Corvettes. The original 3916141 differed slightly in configuration from the later ones such as the one pictured.

Joe,

I assume that the 3916141 fan clutches used in production on 1968-1969 big blocks were similar in appearance
to the fan clutch in the photo below which actually is a "CJ" fan clutch, GM # 3916139 dated "L27G" (Nov. 27, 1966).

Do you agree or did they look more like my NORS 3916141 fan clutch?

Dave

[Joe L.]

Re: Fan clutch

Joe,

I assume that the 3916141 fan clutches used in production on 1968-1969 big blocks were similar in appearance
to the fan clutch in the photo below which actually is a "CJ" fan clutch, GM # 3916139 dated "L27G" (Nov. 27, 1966).

Do you agree or did they look more like my NORS 3916141 fan clutch?

Dave

Dave------



Yes, the original GM #3916141 appeared like the fan clutch you pictured. However, I don't think the one you pictured is a GM #3916139. The GM #3916139 was a Schweitzer fan clutch. I believe the one you pictured is a GM #3916140 which is the Eaton-manufactured equivalent of the 3916139. The 3916140 was a PRODUCTION-only piece, never available in SERVICE.

I expect that both the 3916139 and 3916140 carried the same broadcast code of "CJ". The broadcast code's primary purpose is to allow assembly line workers to quickly and positively identify the correct part for installation. So, as far as assembly line application goes, the 3916139 and 3916140 were the same and, thus, I expect the same broadcast code.

By the way, the only difference I know of between the 3916140 and the 3916141 is the shaft length.

[David L.]

Re: Fan clutch

Dave------



Yes, the original GM #3916141 appeared like the fan clutch you pictured. However, I don't think the one you pictured is a GM #3916139. The GM #3916139 was a Schweitzer fan clutch. I believe the one you pictured is a GM #3916140 which is the Eaton-manufactured equivalent of the 3916139. The 3916140 was a PRODUCTION-only piece, never available in SERVICE.

I expect that both the 3916139 and 3916140 carried the same broadcast code of "CJ". The broadcast code's primary purpose is to allow assembly line workers to quickly and positively identify the correct part for installation. So, as far as assembly line application goes, the 3916139 and 3916140 were the same and, thus, I expect the same broadcast code.

By the way, the only difference I know of between the 3916140 and the 3916141 is the shaft length.

Joe,

I'm sure you are correct that my (or formerly my) "CJ" fan clutch made by Eaton was GM # 3916140 as it was a assembly line fan clutch. Over the years I made a list of fan clutch part numbers and their corresponding 2-digit letter code based on GM documentation that I came across as well as actual NOS GM fan clutches in GM boxes. These part numbers would be service part number but in many cases the same as production part numbers. Here is the list:

"AG" 4950822
"AK" 4947720
"CA" ???????? 3.25" BC
"CG" 4939900 3.25" BC
"CH" 4939899 3.25" BC
"CI" 3946049 3.25" BC
"CJ" 3916139 (Schwitzer), 3916140* (Eaton) 3.00" BC
"CK" 3916141 3.00" BC
"CN" 5489475
??? 3857530 3.00" BC
"CS" 3938944 3.00" BC
"CT" 3857531 3.00" BC
"CV" 3946804 3.25" BC
"CZ" 3946050 3.25" BC

"PC" 4949706 (Pontiac)
"PD" 1386934 (Pontiac)

"BG" 1386934 (Buick)

* Joe's contribution

As a rule of thumb "C" = Chevrolet, "P" = Pontiac, etc.

Dave

[Domenic T.]

Re: Fan clutch

Question,
Need a fan clutch for my 67 BB. Like to get as close to original. Read the posts here and see the spring vs bar type. I see the pics are spring type and LIC shows the bar type. When I punched up "Americas finest corvettes" the site said "file not found".
Which is correct spring or bar? I thought the spring was the one.

Dom

[Donald A.]

Re: Fan clutch

Question,
Need a fan clutch for my 67 BB. Like to get as close to original. Read the posts here and see the spring vs bar type. I see the pics are spring type and LIC shows the bar type. When I punched up "Americas finest corvettes" the site said "file not found".
Which is correct spring or bar? I thought the spring was the one.

Dom

Hi Dom - two fan clutch designs were used for 1967 Corvettes. You can read all about them in the Judging Guide. Schwitzer (bi-metallic thermostatic elements i.e. 'bar' type) and Eaton (coil thermostatic element i.e. 'spring' type). Repros are all different than original some are close. I chose to have an original core restored, see first post in this thread. However if you decide on a repro unit, both types can be used for a '67 Corvette. Just be sure you have the correct one for small block vs big block as they differ.