Rear Spring ID

[Patrick C.]

[Joe L.]

Re: Rear Spring ID

Pat------


From what I can see, it looks to me like a GM #3828811 which was used for cars with F-40 suspension. Please check the forging numbers on your shock lower mount shafts and report.

The unusual thing about it, though, is the plate on the top of the spring. I don't recall that the 3828811 had that plate. In that case, the spring could be a GM #354130 which was a GM replacement spring.

[Gary B.]

Re: Rear Spring ID

Joe,

I think I see 7 leaves plus a flat top plate. So, I'm guessing it's GM HD service replacement 354130. Or possibly GM 363152, taken off of a 76-77.

Gary

[Patrick C.]

Re: Rear Spring ID

Joe,

I think I see 7 leaves plus a flat top plate. So, I'm guessing it's GM HD service replacement 354130. Or possibly GM 363152, taken off of a 76-77.

Gary

The spring is 2 1/4 wide. I thought the 76/77 springs were 2 1/2. The spacer has me puzzled. Height adjustment for a sagging spring?

Yes there are 7 leafs plus a spacer about a 1/4 inch thick.

[Gary B.]

Re: Rear Spring ID

Pat,

The 2.5" wide springs started in 1980. Both GM 354130 and GM 363152 are 2 1/4" wide and had a flat top plate in addition to 7 leaves.

Gary

[Joe L.]

Re: Rear Spring ID

Joe,

I think I see 7 leaves plus a flat top plate. So, I'm guessing it's GM HD service replacement 354130. Or possibly GM 363152, taken off of a 76-77.

Gary

Gary------


Yes, I noted that, too, after my original post. So, I appended my post just a few minutes before you posted.

[Patrick C.]

Re: Rear Spring ID

So the spacer is a GM part? And always used with a 7 leaf spring? I thought it was something somebody added on to make the spring work work with a 64 rear housing.

I am going to take the spring apart tomorrow and check a couple of things. The rear end is turning out to be a bit of a mongrel. Thanks for the help. Judging is coming up on the 27th of April and I have a lot to do yet. My wife thinks this is crazy stuff.

[Joe L.]

Re: Rear Spring ID

So the spacer is a GM part? And always used with a 7 leaf spring? I thought it was something somebody added on to make the spring work work with a 64 rear housing.

I am going to take the spring apart tomorrow and check a couple of things. The rear end is turning out to be a bit of a mongrel. Thanks for the help. Judging is coming up on the 27th of April and I have a lot to do yet. My wife thinks this is crazy stuff.

Gary------


The spacer you have on your spring is part of the spring assembly and was not an "added-on" part. The original 7 leaf spring, GM #3828811, did not have the plate. However, replacement spring GM #354130 did have the plate. The 354130 was originally a replacement for the 7 leaf, 1963-74 F-40/F-41 spring. Later, it also replaced the 9 leaf 64-74 standard spring.

Please check the forging numbers on your lower shock mount shafts. If original, the numbers should be apparent on the non-machined, as-forged portion of the shafts. This could help determine if your car was originally an F-40 suspension car.

[Patrick C.]

Re: Rear Spring ID

Joe,

I think my car just had the regular suspension....but am going to call the original owner to make sure. A lot of changes were made to the rear end but it has stock shock mounts I think?
.

[Joe L.]

Re: Rear Spring ID

Joe,

I think my car just had the regular suspension....but am going to call the original owner to make sure. A lot of changes were made to the rear end but it has stock shock mounts I think?
.

Pat------


These are, indeed, the standard suspension shock mount shafts. I believe they are likely original to the car and is further proof that the car is a standard suspension car. These shafts were replaced, for SERVICE, by the HD suspension shafts many years ago. So, it's unlikely that these were ever replaced, at least not with original part-numbered pieces.

It's now extremely unlikely that the spring you have is a GM #3828811 and is almost certainly a GM #354130 or GM #363152 which would be later replacements.