BillyL

While installing a fuel tank, I counted 7 leaf springs. The JM among other books denotes 7 leafs as part of the F41 suspension. The car has no rear sway bar and the front sway bar is a 3/4" unit. Its all original components under the car. Shouldn't it have 9 leaf springs? Its a '70 conv. 350/350 W/AC late June build. Thanks....

Billy

Alan 71

Hi Billy,
Do I remember this question from the Tech Board on Saturday or yesterday?
I would expect your car to have a 9 leaf spring, as did Joe L.
Regards,
Alan

DAN70

Alan, everything under this Corvette is original to the car. Believe it or not we replaced the original bearings in the trailing arms two years ago, did the fuel tank last week and made the determintion to refresh the whole car. Billy has owned the car for 15 years and bought it from a mutual freind who had owned it 15 years. I just don't know why someone would replace the rear spring and nothing else, at least the previous owner didn't.

wfo76

Memories fade and all kinds of things happened to these cars over the years. F41 only available as part of ZR1 so no way this car had a factory 7-leaf installed at St Louis. Has to be a service replacement or aftermarket spring. The original owner could have complained to his dealer when new about sagging or squeaking in the rear, and bam, there goes your original spring.

DAN70

I know stuff happens. Did all 70-72 have the 9 leaf as the standard set up? Should there be a part # stenciled on the spring pack? Bushings need replacing might as well look for a part #. Thanks.

wfo76

Yes, all 70 models except the 25 with RPO ZR1 had a 9-leaf spring.
Part numbers on the original springs? Now that, I do not know.
I have seen aftermarket 7 leaf springs with painted stencil numbers.

mstanton

When I rebuilt my 70 LT-1's front suspension, I found, to my surprise, that the car had an F41 front sway bar. The rest of the front suspension was original, but I doubt it was factory installed. Rear springs and sway bars are easy to change.

LT-1 kid

i think all 70-72 LT-1s had a 7 leaf spring as standard,with no rear sway bar,except ZR-1-also had the rear sway

wfo76

No, the LT-1s had the exact same suspension as the base engine car which meant a 9-leaf spring.
No factory rear bars on small blocks til 75.

DAN70

Thanks for your input. When we get around to pulling the spring pak out and clean it up we'll bring this thread up again an let you all know what we found. May be some markings on it, I've found markings on other cars hopefully these are no different....

Easy Mike

Possibly.

7T1vette

New guy on the assembly line....didn't know the difference between 7 and 9 leaf springs.... Items like this happened all the time. If it assembled, it got shipped.

a560156

No offense, but I disagree that "this happened all the time". That is wishful thinking. There has not been one documented case of it ever happening.

gbvette62

I know that common wisdom says that F41 was never available on 70-72's and I agree, but I've seen an awful lot of these cars with 7 leaf springs. A freind of mine bought a real barn find 71 LT-1 rag top about 4 years ago. This car had been stored 20 years and had what seemed like a foot of dust on it. This was an unrestored, 90,000 mile car, green on green, with the original carb, starter, alternator, radio, shifter, seat belts, wheels, spare and convertible top and all shielding was in place. This was an untouched car, and yet it had F41 front and rear bars and the 7 leaf spring. The spring was a GM spring and the rear bar was mounted with correct headmark hardware. The car was not a ZR1, it did not have J56 brakes. I'm not saying that this car came with F41, but it didn't look like a car that anyone had ever been into to modify. Some of the tank sticker was there, but not enough to read all the options. My buddy cleaned the car up and intended to take it for NCRS Bow Tie judging, but sold it instead as he had too many projects. The car went to North Jersey and then showed up on E-bay 2 months later. I don't know where the car went after that.

7T1vette

Exactly how does one "document" something that isn't supposed to happen? The only way is to accept anecdotal evidence from the original owners...many of whom will testify to their cars being "exactly as it came from the factory"....yet built with and occasional incorrect item.

As I stated, this happened all the time. When 'proper' stock ran out, the line used what they had; when new people were dumped on the line, they picked up the wrong part and it fit; when production of a particular part was held up (almost never for a quality problem), they would use whatever was available to keep the line running. If you don't believe it, that's OK...but that IS the way it was.

JohnZ

No, it didn't happen "all the time", especially substitution of a special low-volume part where usage was only 25 per year and whose configuration was completely different from the only other high-volume production part. That's a convenient excuse for explaining the presence of a service replacement part.

I spent 38 years in assembly plants (including two at St. Louis), from repairman to Plant Manager, and I know a little about documented substitutions, authorized deviations, and inventory control. That spring is not original to the car.

a560156

Well, you know what they say about opinions, especially when they are unsupported by empirical evidence.

a560156

Thanks John.

DAN70

Billy and I found this, this past weekend. The JM states that the yellow tag means it's a service replacement spring. It looks like the front springs are service replacements so the rear spring was most likely replaced also. Ball joints and bushings look original though.

early shark

Those front coils have the optional F41 heavy duty tag. It just means that a previous owner had the F41 suspension springs (front & rear) installed. I did the same thing with one of my '71's. I have the correct GM F41 springs installed just as the factory WOULD have done had that option been ordered new.