Ink stamp date code on 67 fan-clutch

[David L.]

I just purchased an original 1967 Chevrolet w/A.C. fan-clutch assembly. The 5-blade 18" Scwitzer fan stamped "L6" (November 1966), "912239", and "SC" is one of the two fans used on 1966 & 1967 Corvettes with 327 engine & A.C. (GM # 3863137 as shown in the AIM). The fan-clutch has the following ink stamps on the face: "EATON CJ" and "L27G". I believe the "L27G" indicate a date code November 27, 1966. The measurement from the fan mounting surface to the water pump mounting surface is about 1 25/32". This measurement is about the same as on my 1966 Corvette (Schwitzer) fan-clutch dated "SC 1-26-66".

According to my research the "CJ" fan-clutch is GM # 3916139 and first appears in my 1967 Chevrolet Parts Catalog (effective Apr. 1967) for a 67 Pass w/AC (283,327) and 1967 Camaro w/AC as per the AIM. The fan-clutches used on the 1967 Corvette are GM # 3814560 and 3814137 as per the 1967 AIM. GM # 3814137 is also sold over the counter.

Does anyone have any comments about the fan-clutch date code? Could this "CJ" fan-clutch also have been installed on 1967 Corvettes w/AC?

According to Chevrolet Parts History GM # 3814137 was replaced with GM # 3916139 in Jan. 1968.

[Kevin P.]

Re: Ink stamp date code on 67 fan-clutch

there is the same fan and clutch on ebay right now 260767626189,

[David L.]

Re: Ink stamp date code on 67 fan-clutch

there is the same fan and clutch on ebay right now 260767626189,

Kevin,

You are correct. The fan-clutch appears to be made by Eaton. I suspect that it was also stamped "CJ". I can barely read the ink stampings on my fan-clutch.

Dave

[Gerard F.]

Re: Ink stamp date code on 67 fan-clutch

David,

Here's a picture of a fan clutch from my Jun 29 67 (Vin 22049) 327/300 w/o AC:



It is an Eaton CJ with a date code od L12G. Can't believe that the date code means November 1966, with an engine assembly stamping of 06-26-67.

Guaranteed original to my car which I've owned since 68. I still have the original radiator in it, and only took this fan clutch out about two years ago.

[Ronald L.]

Re: Ink stamp date code on 67 fan-clutch

David,
Do you have other fan clutches with dates that would support the date code theory (I believe you, just interested to see data). I've seen others with CJ, but have to go look, don't think the dates were anywhere legible.

Gerald, your car was made at clean up time. Find all the parts stuffed in the corners of the plant and build them into cars. Clean out the plant for the new model that was soon to arrive.

[David L.]

Re: Ink stamp date code on 67 fan-clutch

a fan clutch from my Jun 29 67 (Vin 22049) 327/300 w/o AC:

It is an Eaton CJ with a date code od L12G. Can't believe that the date code means November 1966, with an engine assembly stamping of 06-26-67.

Guaranteed original to my car which I've owned since 68. I still have the original radiator in it, and only took this fan clutch out about two years ago.

Jerry,

I assume the fan on your 67 Corvette (VIN 22049) without AC has 5 blades and measures 17 1/8" in diameter.

It's interesting that the "CJ" fan-clutch was used on Corvettes in 1967. I thought that it was a good possibility. The "L12G" (November 12, 1966) date code does seem a bit early for a June 16, 1967 engine date but it is possible. I hope we can get more examples of original 1967 fan-clutch assemblies.

Dave

[David L.]

Re: Ink stamp date code on 67 fan-clutch

David,
Do you have other fan clutches with dates that would support the date code theory (I believe you, just interested to see data). I've seen others with CJ, but have to go look, don't think the dates were anywhere legible.

Gerald, your car was made at clean up time. Find all the parts stuffed in the corners of the plant and build them into cars. Clean out the plant for the new model that was soon to arrive.

Ron,

The only other examples of original Eaton fan-clutches with ink stamped date codes that I have or have seen are from 1970 Z28's. I will post that data.

Dave

[Jack H.]

Re: Ink stamp date code on 67 fan-clutch

"Can't believe that the date code means November 1966, with an engine assembly stamping of 06-26-67."

PSST, Jerry... Check our your copy of the '67 AIM. You'll find both the fan and fan clutch were installed at the final line in St. Louis.

They were NOT put on at the engine plant(s) in Flint/Tonawanda...

[David L.]

Re: Ink stamp date code on 67 fan-clutch

My date code theory for Eaton fan-clutches in the 1960's is as follows:
F = 1965
G = 1966
H = 1967
I = 1968
J = 1969

Examples:
1. 6" dia. Eaton coil-type fan-clutch stamped "A15F" (January 15, 1965) with 5-blade 18" fan from swap meet.
2. 6" dia. Eaton coil-type "CJ" fan-clutch stamped "L27G" (November 27, 1966) with 5-blade 18" fan Schwitzer fan dated "L6" (November 1966).
3. 7 1/4" dia. Eaton "CV" fan-clutch stamped "H22J" (August 22, 1969) with 7-blade 18" 3947772 fan Schwitzer fan dated "H69" (August 1969).

Apparently in 1970 the Eaton date code changed and here is my date code theory for the 1970's.
A = 1970
B = 1971
C = 1972
D = 1973
E = 1974
F = 1975
G = 1976

Examples:
1. Original 1970 Camaro Z28 7 1/4" dia. Eaton "CV" fan-clutch stamped "A20A" (January 20, 1970).
2. Original 1971 Monte Carlo 7 1/4" dia. Eaton "AG" fan-clutch stamped "E4B" (May 4, 1971) with 3976065 7-blade fan.
3. 7 1/4" Eaton "AK" fan clutch stamped "E15FB" (May 15, 1975) with 7-blade 3991431 fan dated "C75" (March 1975).

As far as I know there were 3 companies that made fan-clutches in the 1960's and 1970's:
Schwitzer (bar strip on front)
Delco Prod. Div. GMC (coil type spring).
Eaton (coil type spring)

It appears to me that many NCRS members have absolutely no interest in researching date codes on parts.
I guess "living in denial" is a very safe way to restore vintage cars.

Dave

[Ronald L.]

Re: Ink stamp date code on 67 fan-clutch

Dave, Not all, to the left you have the 'don't want to be that detailed or know' and to the right you have 'this should be like we build cars today'.

Everything has and had a specification, part number, drawing, and process specification and much of it was dated. The good thing is the big shows are coming up where data gathering is possible if you can get to them to look at barn find one owner time capsules.

You've got onto some good ones, keep the spirit.

[David L.]

Re: Ink stamp date code on 67 fan-clutch

Ron,

Why would anyone comment on something that they had never studied or researched before and have absolutely no data to back up their comment? I guess "rookies" do this all the time.

Dave

[Mike E.]

Re: Ink stamp date code on 67 fan-clutch

David--
My unmolested 67 non-air base-motor car (#18621) has clutch fan stamped B13H (as well as CJ). That would fit as a Feb. 13 67 date with a car with a trim tag of J03.
Keep up the good work--we are kindred spirits on figuring out dating of parts and relationships between part dates and car builds. (re my 4 articles over the years in the Restorer on dates, as well as several articles on specific cars and their dates.
Mike

[Brian M.]

Re: Ink stamp date code on 67 fan-clutch

My 67 VIV 7471 has the fan as described in the opening post and a CJ stamped Eaton clutch don't remember the date or if it's visible. The car was judged 6x's, first time total deduct for fan 5/5 comment wrong next 4 judgings no issue, last judging National 2007 no deduct but comment of SRP service replacement. The addition of A/C usually throws a curve ball to the judges. JMHO

[Wayne M.]

Re: Ink stamp date code on 67 fan-clutch

Dave, Ron et al. --- does this fit in anywhere with year dates ? Top one is A3I; I believe those 2 black dots on the right are just the edge of the stamp.

And the dirty one below I just wiped it again with methanol, then laquer thinner (I destroy as I unearth ) and I think I get A3D; not visible in this pic.

When did the 1st design square fluid reservoirs / wings change to the angled appearance ?

I have no idea what cars these might have been on.

[David L.]

Re: Ink stamp date code on 67 fan-clutch

Wayne,

According to my date code theory your "A3D" fan-clutch would be January 3, 1964, and your "A3I" fan-clutch would be January 3, 1968.

I believe that the date codes on the Schwitzer fan-clutches (w/bar strip) first appeared in 1965. As many mid-year Corvette owners know that the date codes on these fan-clutches are stamped on the edge of the hub that bolts on to the water pump.

Do you remember the thread that I started on the "almost" 1964-1965 Corvette w/AC 7-blade fan? That fan (3.25" bolt circle) came from a 1964 Buick LeSabre w/AC. I believe that the fan-clutch was original but I am not 100% positive and it had the "angled" fluid reservoirs. I bought in on Ebay as shown in the link below. Doesn't it look like a 64-65 Corvette 327 w/AC fan?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=360337895634&viewitem=

I believe that the "angled" fluid reservoirs first appeared in 1968 or 1969 on the Chevrolet Eaton fan-clutches based on what I have seen in junk yard cars in the past 30 years.

BEWARE: Lacquer thinner or any other solvent will usually wash away ink stampings.

Dave