67 mono leaf spring shape opinion

[Mike S]

 Aside from a final polish and wax, I'm finally done with the 67 L35 convertible restoration.
But, I'm bothered by what I think may be a potential issue with the original factory mono leafs.
In the picture I put an arrow under what is a slight upward bend in the front portion of the left mono spring. This exists on both L & R sides. Looking at the unrestored 67 L35 coupe, those areas are straight across. When I put a flat piece of metal against the convertible spring by the bend you can see a gap. Plus the height in area for 'Dimension J' in AIM 3/A12 measures 1/2" short whereby the coupe is within specs. The car's stance looks fine otherwise.
  I'm thinking of retiring those springs for a set of replacements even though the replacements don't have the end to center taper as viewed from the top. My fear is breakage in that area and losing control of the car. Would any mono spring car owners please take a peek and see if your spring has that upward bend?  I'm curious.

Thanks!
Mike

[bertfam]

Mike, that's a typical issue when cars were fitted with aftermarket traction bars back in the day. Especially the CHEAP (or non-Camaro) traction bars!! The "good" ones would also deform the springs, but much closer to the front bushings. Maybe an inch or two back. The REALLY good ones (like Lakewood) had the snubber directly under the bushings so they didn't deform the springs.

I haven't installed traction bars in AGES, so I don't know if the newer designs have improved, but I believe most of the newer style don't even use "snubbers".

Ed

[67conv6cyl]

That picture intrigues me.......now I what to see the rest of the car, looks like a quality restoration!!

[tomstiel]

I have drag raced a ton of F bodies with mono leaf springs, what I do know for fact, is that if it breaks, it wont be there,they break, or actually crack, in the axle perch area, specifically where the rubber cushion ends at the spring itself. What happens is water will sit and rust a line across the spring perpendicular,causing a stress riser. Looking at the shape of the spring looks like there may be a ride height problem ?

[tomstiel]

Sorry, after re reading your post, I see know you have no issue with ride height, But still, spring wont break in that area, my O2

[Mike S]

Ed,

   Wow.....you may be onto something. The car was raced by the previous owner before he passed away and did have traction bars on it despite the fact that the square factory bar was on it too. I remember them being the clamp on type and not the ones that replaced the shock perch.
I forgot about that until I read your reply. That may be the cause of the shape!?
  Tom, the ride height is approximately 1/2" below specs when taking into account the options as listed in the AIM.
As for ride performance the car rides well and it doesn't bottom out. The springs were in great shape as rust goes especially in the area between the rubber perch cushions. I read somewhere that GM designed the mono spring with its tapered shape (height and width) so if it did break it would be in the perch area as you mentioned.
  I'll post pictures soon. I'm really proud of the way the restoration came out.

Thanks for the replies!
Mike

[bertfam]

I remember them being the clamp on type...

Yep. Those are the ones that'll really do a number on the springs! Especially the mono leaf springs.

Ed

[Mike S]

 If the traction bars did indeed change the shape of the springs, then IYHO, would you think they were weak in that spot?
Or, am I worrying over nothing (likely the case).

Mike

[bertfam]

I wouldn't worry about it. These cars aren't beat to death anymore like they were in the 60's 70's and 80's so they'll probably last long after we're gone!

Ed