1960 Part Look Up

[Joe M.]

To install the fan clutch on the fan blade assembly, the 1960 AIM calls out two types of washers, 120214 L.W. which is a 5/16" lock washer and 3772747 S.W. I could not find the S.W. part in my Chevy P & A Catalog, dated Feb. 1, 1961. Is it some type of spring washer? If so, what is the modern equivalent?

[John F.]

Re: 1960 Part Look Up

I thought it stood for "split washer" which is a lock washer in my mind.

[Joe M.]

Re: 1960 Part Look Up

I suspect that there must be some difference or there would not be two different part numbers. I am surprised it was not listed in my 1961 updated Chevy P&A.

[John F.]

Re: 1960 Part Look Up

Joe, also "star washer".

[Joe M.]

Re: 1960 Part Look Up

John, GM called them external tooth lock washers in the Parts & Accessories book.

[Richard M.]

Re: 1960 Part Look Up

Joe, 3772747 never shows up in a search on http://www.gmpartswiki.com in any book listed.

I think it's a Spring Washer as you do. In Group 8.928 in the P&A 30 parts Book, it shows several sizes, but notice not 5/16". I suspect 3772747 was never a Service part.

http://www.gmpartswiki.com/getpage?pageid=67140 (see lower right corner of page)

Can you post a picture/scan of your 1960 AIM showing where the 3772747 SW is placed?

Rich

[Joe M.]

Re: 1960 Part Look Up

I included it in current post titled "Original Copy of 1960 A.I.M."

[Richard M.]

Re: 1960 Part Look Up

Strange.......Maybe "SPECIAL" washer. ????

Assy shows Bolt, then LW then SW. Maybe it has a special bevel to allow it to be flat to the flange which also appears beveled.

[Joe M.]

Re: 1960 Part Look Up

I figured it out in a roundabout way by looking at page 964 of 1961 P&A. It shows a 5/16" washer in Group 8.929. It was probably referring to a 5/16" cadmium-plated plain washer (small), P/N 120393. With a slotted mounting plate, it would make sense to use a plain washer between the slot and the lock washer. The 1960 AIM reference is a typo.