correct S/B 69 base model fan clutch

[Roger D.]

I took the fan and clutch off of my donor car thinking this would be correct for my project car. To review the project car is a base model 69 coupe C04. he donor is the exact same car , same color, D5. I don't see a number on the thin base and I don't know what the clutch face info is telling me. Thank You Roger

[Edward J.]

Re: correct S/B 69 base model fan clutch

Roger,I believe that the clutch in the pic maybe a service replacement, Schwitzer was the OEM clutch and was dated on flange.

[Joe L.]

Re: correct S/B 69 base model fan clutch

I took the fan and clutch off of my donor car thinking this would be correct for my project car. To review the project car is a base model 69 coupe C04. he donor is the exact same car , same color, D5. I don't see a number on the thin base and I don't know what the clutch face info is telling me. Thank You Roger

Roger-------


This is absolutely not the original fan clutch. It's a SERVICE replacement of GM #3916141. Original versions of this fan clutch were used on some 1968-70 big blocks.

The original fan clutch for 1969 300 HP Corvette applications was a GM #3916139. This was a Switzer fan clutch with a "bi-metallic", bar-style thermostat.

[Roger D.]

Re: correct S/B 69 base model fan clutch

Thank you gentleman, I guess I will leave what on the project car for now. It is a Switzer bar style thermostat but the flange is dated early 70. OH well!

[Roger D.]

Re: correct S/B 69 base model fan clutch

I would really like to find the correct clutch date flange for my 69. I will sell the 70 unit that I have know since it is close but no cigar. Would I be looking for a 68 flange since it is a C04 69. Anyone

[Joe L.]

Re: correct S/B 69 base model fan clutch

I would really like to find the correct clutch date flange for my 69. I will sell the 70 unit that I have know since it is close but no cigar. Would I be looking for a 68 flange since it is a C04 69. Anyone

Roger------


Yes, you'd need a date code prior to October, 1968, something in the range of April to September, 1968.

[Roger D.]

Re: correct S/B 69 base model fan clutch

Joe my assumption is that there is no difference between BB & SB just if you have AC or not. Is that correct.Thanks

[David L.]

Re: correct S/B 69 base model fan clutch

The 69 Corvette AIM lists 3 fan clutches (UPC 6, sheet A4):GM # 3916139, 3916140, and 5329100.

Enclosed is a photo of NOS 3916139 fan clutch stamped "CJ"and made by Schwitzer that I got off the web.
The Eaton company also made a "CJ" fan clutch as shown in the bottom photo dated K20H (Oct. 20, 1967).
GM # 5329100 was made by Delco Prod. Div. G.M.C.

[David L.]

Re: correct S/B 69 base model fan clutch

Here is another original factory installed fan clutch stamped "EATON", "CJ", and "L27G" (Nov. 27, 1966) that is attached to a 18"dia., 5-blade fan stamped "912239", "SC", and "L6" (Nov. 1966). The fan is the optional fan, GM # 3863137, used with A.C. as shown in the 1967 Corvette AIM (UPC C60, sheet C2) as well as other 1967 Chevrolet V8 models w/ A.C.

Dave

[Roger D.]

Re: correct S/B 69 base model fan clutch

David, I was under the impression that the clutch I would be looking for would have a bar thermostat instead of a spring.

[David L.]

Re: correct S/B 69 base model fan clutch

David, I was under the impression that the clutch I would be looking for would have a bar thermostat instead of a spring.

Roger,

Since I was not on the 1969 Corvette assembly line and have not done a survey of 1969 Corvette fan clutches I can only go by what is in the assembly manual ( 3 fan clutches listed). In many cases Chevrolet got parts from 2 or even 3 vendors for two reasons: to main a steady supply on the assembly line as well as create competition between vendors to keep costs down. I know that the 63-67 Corvettes were issued either a bar type (Schwitzer) or a coil spring type (Eaton) fan clutch on the assembly line. Maybe owners of 69 Corvettes that have their original fan clutch will respond.
My 1966 Corvette (Feb. 24, 1966) came with a Schwitzer fan clutch (bar type) stamped "SC 1-26-66" on the edge of the hub.

Dave

[Roger D.]

Re: correct S/B 69 base model fan clutch

Thank you David for your experise on the confusing matter. Not easy when GM used so many different parts and we have to try and match what they did. Thanks Roger

[Joe L.]

Re: correct S/B 69 base model fan clutch

Thank you David for your experise on the confusing matter. Not easy when GM used so many different parts and we have to try and match what they did. Thanks Roger

Roger------


My original owner 1969 built in September 1969 was equipped with the Switzer clutch. A friend who is the original owner of his October, 1968 build 1969 with L-46 also has the exact same fan clutch as used on my car. I believe the majority, if not all, 1969 Corvette small blocks were equipped with the Switzer clutch, GM #3916139. I believe one of the alternative clutches specified in the AIM, GM #3916140, was an Eaton clutch. Just how many of these were used in PRODUCTION, if any, I do not know. However, I strongly believe that if they were used, at all, they were the exception and not the rule.

In general (but NOT exclusively), big block fan clutches had a slightly shorter shaft than small block clutches. For example, the 3916141 fan clutch was originally used for big block applications and had a slightly shorter shaft than the 3916139 used for small blocks. While the 3916141 later became the SERVICE fan clutch for both big blocks and small blocks, it was originally used only for big blocks.

[Roger D.]

Re: correct S/B 69 base model fan clutch

Thank you Joe I will start my search for one. May be hard to find.

[Roger D.]

Re: correct S/B 69 base model fan clutch

I hate to beat a dead horse but is this what I am looking for. 5 15 68 but I don't see Schwitzer anywhere. I cannot load a picture for some reason. I can email someone for opinion or go to the forum to my rvzio 69 restore post. Thank you