&F40 / &F41 Rear Spring ID

[Joe L.]

Re: &F40 / &F41 Rear Spring ID

Gary-------


I think it could be the GM #354130. This spring ultimately replaced the GM #3828811 for SERVICE. The 354130 was discontinued without supersession in February, 1999. There were actually two other springs that were used in PRODUCTION and available in SERVICE between the 3828811 and the 354130. These were the GM #3977378 and the GM #370350. The 3977378 replaced the 3828811 in some "unofficial" and undocumented manner about 1970 or 1971. It was discontinued in October, 1976 and replaced by the 370350. The latter was then discontinued and replaced by the 354130 in September, 1981. I have no information whatsoever on either the 3977378 or the 370350.

I actually have an NOS example of the 354130. Unfortunately, getting at it is just too difficult so I cannot picture or otherwise describe it. I do know that it's a 7 leaf spring.

[Gary B.]

[Richard M.]

Re: &F40 / &F41 Rear Spring ID

Yes good question. Hope Joe has info on that.

BTW, I've sent a request to Bill Sangrey(Archives Director) and asked if he knows if he may have prints of the springs in his archive at the AACA library. If you may recall he got me the Saginaw Steering column prints a while ago.

Rich
PS Gary/Joe, I posted that spring data chart on the DoRD update page. HERE

[Gary B.]

Re: &F40 / &F41 Rear Spring ID

Richard,

Thanks for posting the spring info table.

I have a fair number of copies of GM leaf spring engineering drawings that Franz Estereicher gave me many years ago, and all of them specify the 45-deg end cuts on the main leaf. But there could be revised GM drawings, or drawings for later GM springs that allowed the end cuts to be non-45 deg. Maybe the non-45 deg version was for service replacement parts, or for one of the springs that Joe mentions in his post above that are not in the production leaf spring table I posted.

Gary

[Richard M.]

Re: &F40 / &F41 Rear Spring ID

Richard,

Thanks for posting the spring info table.

I have a fair number of copies of GM leaf spring engineering drawings that Franz Estereicher gave me many years ago, and all of them specify the 45-deg end cuts on the main leaf. But there could be revised GM drawings, or drawings for later GM springs that allowed the end cuts to be non-45 deg. Maybe the non-45 deg version was for service replacement parts, or for one of the springs that Joe mentions in his post above that are not in the production leaf spring table I posted.

Gary

Gary, ok thanks.

Any chance you can send me some jpegs of those so I can add them to DoRD? I'll still try to get them from Bill too and maybe he may have revised prints.

Rich

[Gary B.]

[Richard M.]

Re: &F40 / &F41 Rear Spring ID

Ok thanks. Bill just sent me a note that he'll check for them. I gave him all of the numbers....
3828811
3977378
354130
3828811
354130

[Ray K.]

Re: &F40 / &F41 Rear Spring ID

[Joe L.]

Re: &F40 / &F41 Rear Spring ID

Joe,

Have you ever seen a known GM spring with the non-45 degree end cuts on the main leaf?

I’ve always wondered why some repro springs have those non-45 deg cuts unless there is some GM drawing or spring they are copying.

Gary

Gary------


I just do not recall if I've seen GM springs with other than a 45 degree corner cut on the main leaf. VERY VAGUELY I seem to recall that the 354130 I have has the 60 degree cut but I'm far from certain about it. I wish I could access the 354130 spring I have but it's just too daunting at the moment.

I do believe, though, that the spring pictured in the original post of this thread is a GM-sourced spring. While the ends of leaves 1-6 do not have the slightly reduced end width usually seen in the GM springs, note the configuration of the upturned leaf ends. That configuration is seen in GM springs but, so far, I've not seen it exactly duplicated in reproduction springs. In addition, that springs just "feels like" a GM-sourced spring to me.

[Joe L.]

Re: &F40 / &F41 Rear Spring ID

Tim, For reference, here is a F40 spring on a '65 fuelie. Best of my knowledge original. Appears identical to yours.

The only caveat is that I believe service replacements used that flat extra leaf on top. Not sure if 65 used that or not.

Rich

Rich------


I do not think this is an original GM spring. From what I can see of them, the leaf ends just do not have the typical configuration of GM springs.

[Gary B.]

[Richard M.]

Re: &F40 / &F41 Rear Spring ID

Rich------


I do not think this is an original GM spring. From what I can see of them, the leaf ends just do not have the typical configuration of GM springs.

Joe, Yes after this thread progressed, I agree.

Rich
P.S. for reference, to eschew obfuscation, the spring pictured in Post#2.

[Ray K.]