Need help to ID this clutch fan assy - NCRS Discussion Boards

Need help to ID this clutch fan assy

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Greg L.
    Extremely Frequent Poster
    • March 1, 2006
    • 2291

    Need help to ID this clutch fan assy

    I was sorting out some of my parts this past week and came across this clutch fan assy and was wondering if anyone could ID it for me. I'm not even sure if it's a Corvette part or not. I couldn't find any numbers on it other than the ink stamps(413976 CY) in the pic. The fan is aluminum and I'm guesing it's off of my buddies old 77 L82 if that helps.
    Thanks.
    Attached Files
  • Joe L.
    Beyond Control Poster
    • February 1, 1988
    • 43219

    #2
    Re: Need help to ID this clutch fan assy

    Originally posted by Greg Linton (45455)
    I was sorting out some of my parts this past week and came across this clutch fan assy and was wondering if anyone could ID it for me. I'm not even sure if it's a Corvette part or not. I couldn't find any numbers on it other than the ink stamps(413976 CY) in the pic. The fan is aluminum and I'm guesing it's off of my buddies old 77 L82 if that helps.
    Thanks.

    Greg-----


    It might have come off your buddy's 1977 L-82 but, if it did, I don't think it originally resided there. So, what is it? Well, it's just what it says it is----a GM #413976. So, what's that? Well, as far as I can tell, it's a fan clutch originally used on some Oldsmobiles, Buicks, and Pontiacs in the mid 70's. I can find no Chevrolet applications for it, though. However, from what I can see of it, its configuration is similar to the GM #460742 used on some 1972-79 Corvettes.

    By the way, the fan attached to it is probably a GM #413977. Also, no Corvette ever used a fan blade assembly that was manufactured of aluminum and none that I know of ever used a 6 blade fan.
    In Appreciation of John Hinckley

    Comment

    • Greg L.
      Extremely Frequent Poster
      • March 1, 2006
      • 2291

      #3
      Re: Need help to ID this clutch fan assy

      Thanks Joe. I thought it might be a Corvette part and worth keeping but since it's not I guess I'll file it.

      Comment

      • Tom L.
        Extremely Frequent Poster
        • October 17, 2006
        • 1439

        #4
        Re: Need help to ID this clutch fan assy

        Joe, Just checking because I'm looking (with little luck) for a fan blade for a '72 454 w/ A/C, the 7 bladed one with the tips, aren't the blades aluminum?

        I saw one at carlise and it was in poor shape and didn't think I could bend the aluminum blades back into shape and not weaken the aluminum.

        Comment

        • Joe L.
          Beyond Control Poster
          • February 1, 1988
          • 43219

          #5
          Re: Need help to ID this clutch fan assy

          Originally posted by Lynn Larsen (46337)
          Joe, Just checking because I'm looking (with little luck) for a fan blade for a '72 454 w/ A/C, the 7 bladed one with the tips, aren't the blades aluminum?

          I saw one at carlise and it was in poor shape and didn't think I could bend the aluminum blades back into shape and not weaken the aluminum.
          Lynn----


          I suppose it's possible, but not to my knowledge. I've had these fans in my hands many times and I never noted that the blades were aluminum. I might have missed that, though.

          Anyone have one on or off a 70-74 454 with A/C they can check?
          In Appreciation of John Hinckley

          Comment

          • Terry M.
            Beyond Control Poster
            • September 30, 1980
            • 15599

            #6
            Re: Need help to ID this clutch fan assy

            I have looked at a lot of them -- some were somewhat bent -- the clearances to the shroud are tight by design, and thus the reason for engine mount shims on Mark IV with AC in the early C3s, but I digress.

            I never use a magnet, but I doubt they are aluminum -- but this could be another chance for me to learn something new. I'll be watching.
            Terry

            Comment

            • Harmon C.
              Extremely Frequent Poster
              • August 31, 1994
              • 3228

              #7
              Re: Need help to ID this clutch fan assy

              I judged one of thease fans with the tips last Friday so Bill M. should let us know for sure but I vote for steel.
              Lyle

              Comment

              • D S.
                Extremely Frequent Poster
                • March 1, 2005
                • 1551

                #8
                Re: Need help to ID this clutch fan assy

                I put a strong magnet on the tipped blades on my 1970 LS-5 with AC and it didn't stick to any of the blades so the blades aren't steel. Surprised me though.

                Scott Sims
                Texas Chapter

                Comment

                • Joe L.
                  Beyond Control Poster
                  • February 1, 1988
                  • 43219

                  #9
                  Re: Need help to ID this clutch fan assy

                  Originally posted by D Scott Sims (43568)
                  I put a strong magnet on the tipped blades on my 1970 LS-5 with AC and it didn't stick to any of the blades so the blades aren't steel. Surprised me though.

                  Scott Sims
                  Texas Chapter

                  Scott-----


                  Well, it sounds like this might be another case of "never-say-never". I have most of the 69-82 fan blade assemblies in NOS form. I have not found one of them to have anything but steel fan blades. Although I don't have any NOS examples of most earlier fan blades (except those that were also used for 1969-70), I am pretty familiar with them and/or have the GM specs for them. None that I know of have aluminum blades.

                  However, while I've inspected the 70-73 big block with A/C fan blades, I don't have any in my collection or specs for them. There were actually THREE different fan blade assemblies used over the period for big block with C-60 applications.

                  The first was GM #3969926. This was used from the start of 1970 production until ABOUT June, 1970. After that, until the end of 1970 production, GM #3993889 was used. I've never been able to figure out just what the difference was between these fan blade assemblies. MAYBE we now have. What is the build date of your car? Are there any other 1970 LS-5 with C-60 owners out there that can report on their date of build and fan blade material. It's real easy to check with a magnet.

                  For 1971-73 fan blade assembly GM #3992095 was used for all big blocks with C-60. This fan blade is of similar configuration to the 1970 fan blades EXCEPT that it has a larger center hole and larger bolt circle for retention to the fan clutch. Without changing the fan clutch and waterpump, the 1970 configuration fan blades cannot be interchanged with the 1971-73 and vice-versa. Anyone out there with a 71-73 big block with C-60 with "tipped" fan blade that could check the blades for us with a magnet? Most appreciated.
                  In Appreciation of John Hinckley

                  Comment

                  • James W.
                    Expired
                    • December 1, 1986
                    • 278

                    #10
                    Re: Need help to ID this clutch fan assy

                    My 71 LS5 C60 (9465) had a crack develop near the base of the blade where it is riveted. It had steel blades.

                    Jim

                    Comment

                    • D S.
                      Extremely Frequent Poster
                      • March 1, 2005
                      • 1551

                      #11
                      Re: Need help to ID this clutch fan assy

                      Joe, my fan blade is the #3969926 dated A70. Up until this post I assumed it was steel like so many other fan blades but did note that the blades appeared aluminum-like when the paint was worn and chipped before I repainted them. I also noted the tips seemed to bend easier than steel but gave it no thought. I guess the thickness is unlike those after-market flex fans and that may be the reason why it was assumed they were steel.

                      I just sent out an email survey to several friends who own 1970-1972 LS-5s with AC and hopefully we'll find out what they say about magnets sticking to the blades. It may take a while for the results to come in because so many of them have their Corvettes in storage and/or car haulers.

                      I just went back to my garage to double-check. The magnet won't stick to the blades but will to the riveted supports.

                      Comment

                      • D S.
                        Extremely Frequent Poster
                        • March 1, 2005
                        • 1551

                        #12
                        Re: Need help to ID this clutch fan assy

                        Originally posted by James White (10751)
                        My 71 LS5 C60 (9465) had a crack develop near the base of the blade where it is riveted. It had steel blades.

                        Jim
                        A magnet will stick near there because of being so close to the riveted steel. Did you place a magnet on the tipped ends?

                        Comment

                        • D S.
                          Extremely Frequent Poster
                          • March 1, 2005
                          • 1551

                          #13
                          Re: Need help to ID this clutch fan assy

                          Bill Chamberlain says in an email to me:

                          The blades on my 72' fan are aluminum (or some other alloy) - no sticking magnets...
                          My fan is the birth fan to my car.



                          Thank You.

                          Bill Chamberlain
                          Director of Sales and Marketing

                          Comment

                          • Jim M.
                            Frequent User
                            • August 31, 1986
                            • 50

                            #14
                            Re: Need help to ID this clutch fan assy

                            My '71 LS-5 car with C60 has the 3992095 fan dated H70 and the blades are non-ferrous metal.

                            Comment

                            Working...
                            Searching...Please wait.
                            An unexpected error was returned: 'Your submission could not be processed because you have logged in since the previous page was loaded.

                            Please push the back button and reload the previous window.'
                            An unexpected error was returned: 'Your submission could not be processed because the token has expired.

                            Please push the back button and reload the previous window.'
                            An internal error has occurred and the module cannot be displayed.
                            There are no results that meet this criteria.
                            Search Result for "|||"