GM number 3774937 fuel level sender locking cam (lock ring) markings

[Tom D.]

I've noted "O2" stamped on the fuel sender locking cam sold (but not made by) Paragon as number 3860. It's listed for '63-'74.

Both the 1965 A.I.M. (UPC 8, B1.) and my old GM box of ten reference GM 3774937. Those ten I bought in the seventies had "A" stamped on them. I've decided to use the "A" version for my most recent project, but now I am curious...

My NCRS 1965 TIM&JG is to be consulted in a few minutes, as it's not nearby at the moment. (I will add to this is I find something therein.)

The NCRS 1963-1964 TIM&JG does not mention this ring. Also, my NCRS 1966 TIM&JG does not mention it.

The NCRS 1968-1969 TIM&JG 5^th edition, Chassis page 242 31 is often found on the sending unit mounting ring, but other numbers have been seenNCRS 1970-1972 TIM&JG 5^th edition, Chassis page 222 31I wonder what locking cam numbers have been seen on original 63-67 Corvettes. If not "31", I wonder what '65s had...

[Larry M.]

Re: GM number 3774937 fuel level sender locking cam (lock ring) markings

I have only seen "A" for the C2 cars.

Larry

[Mike M.]

Re: GM number 3774937 fuel level sender locking cam (lock ring) markings

i have six original lock rings off c2s , all have GH stamped on them. GH, not GM.. mike

[Don H.]

Re: GM number 3774937 fuel level sender locking cam (lock ring) markings

the 6th 1965 JG says the cad or zinc plated locking ring secures the sender unit but does not say if anything is marked thereon. Chassis Pg. 228.

[Joe L.]

Re: GM number 3774937 fuel level sender locking cam (lock ring) markings

I've noted "O2" stamped on the fuel sender locking cam sold (but not made by) Paragon as number 3860. It's listed for '63-'74.

Both the 1965 A.I.M. (UPC 8, B1.) and my old GM box of ten reference GM 3774937. Those ten I bought in the seventies had "A" stamped on them. I've decided to use the "A" version for my most recent project, but now I am curious...

My NCRS 1965 TIM&JG is to be consulted in a few minutes, as it's not nearby at the moment. (I will add to this is I find something therein.)

The NCRS 1963-1964 TIM&JG does not mention this ring. Also, my NCRS 1966 TIM&JG does not mention it.

The NCRS 1968-1969 TIM&JG 5^th edition, Chassis page 242 states “…mounted in the tank with a zinc-plated locking ring. 31 is often found on the sending unit mounting ring, but other numbers have been seen. “ (Way to go Patrick and team!)

The NCRS 1970-1972 TIM&JG 5^th edition, Chassis page 222 states “…mounted in the tank with a zinc plated locking ring. 31 is often found on the sending unit mounting ring. “

I wonder what locking cam numbers have been seen on original 63-67 Corvettes. If not "31", I wonder what '65s had...

Tom------


I'm very confident that the embossments on these cams represent a manufacturer's ID. These cams were used on just about all GM cars and trucks in the 1961-74+ period. So, there were millions of them being made and, likely, by multiple manufacturers, either at any given time or over the years of manufacture. I have seen "A" and "G.H." and there are probably others, too. Almost 60 years after its release, the GM #3774937 is still available from GM for about 5 bucks, GM list.