fiberglass springs and ride height issues ??

There have been quiet a few threads about aftermarket fiberglass springs and associated ride height problems. It seems that the TRW style spring is the worst when it comes to ride height, VBP springs seem to be close to stock height but sometimes requires 8" long bolts (stock 6").
Aftermarket or re-arched steel springs can also raise the vehicle to almost 30" (ground to fender lip), stock ride height is 26"-27".

Share your experience here, if you have photos that's even better.

Here's a very old pic of my '79: aftermarket 9-leaf steel spring with stock 6" bolts. Ride height was at a whooping 30".





I dropped the car using 8" bolts. It was still at 28" so I bought 10" bolts from www.mcmastercarr.com --- since then I installed a 7-leaf spring that works fine with 8" bolts.

It also appears than height differences from left to right are not unusual. before you adjust the left and right spring bolts to compensate for the ride height check your body mount cushions, they might be deteriorated and let the body sit uneven.

Offsets left/right have also been reported very often. While this has nothing to do with the spring it becomes more apparent when the car is lowered and the tire is close to the fender - again, the body can be moved left/right after you loosen the body mounts.

I used C4 bolts from Ecklers, McMaster will be cheaper!

I think the ride height issues were only with the Muskeegon spring.

Kid Vette might have some insight into this problem:twitch:

Yes, the Muskegon TRW spring has been bashed many times.... ush:

More issues that you can run into:

- if you use 10" bolts the end of the spring comes very close to the tire sidewall. When the tire flexes (and the huge sidewall of a 255-60-15 tire flexes a lot) then you might be cutting your tire on the spring.

- If you get a flat tire the bolt will drag on the road and this can rip the spring off the differential cover

Mine had too much arch

I have a fiberglass spring that sits nice and low though

600# rate

Heres my guldstrand 5 leaf

It's perfect,I think those are 8" bolts

That is pretty much what it should look like, halfshafts almost parallel to the ground, slightly sloped towards the wheels.... spring has some arc to it, bolts are short enough to locate the spring end above the tire... if you get a flat the bolt will not drag on the road....

The coils around the spring bolts are for looks only ?

great photo :1st:

Here's another photo that shows the 9-leaf spring with too much arc and too long bolts:
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I used a 1" spacer to move the wheel further out, to gain some clearance to the spring.

BBShark said:

I think the ride height issues were only with the Muskeegon spring.

Kid Vette might have some insight into this problem:twitch:

Click to expand...

:lol: Muskegon Brake. . . hopefully they will give up on making composite springs eventually. They have no clue.

MYBAD79 said:

There have been quiet a few threads about aftermarket fiberglass springs and associated ride height problems. It seems that the TRW style spring is the worst when it comes to ride height, VBP springs seem to be close to stock height but sometimes requires 8" long bolts (stock 6").
Aftermarket or re-arched steel springs can also raise the vehicle to almost 30" (ground to fender lip), stock ride height is 26"-27".

Share your experience here, if you have photos that's even better.

Here's a very old pic of my '79: aftermarket 9-leaf steel spring with stock 6" bolts. Ride height was at a whooping 30".

Click to expand...

I have measured the FRAME in both front and rear of my car with the 8" bolts and VBP 360 spring, and 460 in front....it's dead level to the frame specs for a '72.....per the manual....

now thing thats funny.....my fenders were reworked to custom show car at one time, and then re narrowed to the present shape...BUT when looking at my fenders really close to a late shark, I seen just about NO differances....

BUT my fender opening height most guys use for reference is 29 in front and rear also....go figger....

I can't spot where/how it's all that differant from a late shark.....when you say your height shuld be 26-27".....I have to wonder what you frame specs to ground were and are now....

that's a lot of glass to loose somewhere it can't be found....even with a tape measure...

:stirpot:

Been there, done that. 10" bolts with STOCK 82 spring, one corner -> tire blow out. NICE! Had to ground the end of the spring and use small spacers. Tires were 255s. I had 275s on mine 10" bolts and stock spring, no issues. Weird!

Can you dearch a spring if so how ?

Anybody have firsthand experience with Hyperco composite springs?

Van Steel sells them, they are cambered & tapered springs, just like the original GM fiberglass ones.

Are they arched appropriately?

Twin_Turbo said:

Been there, done that. 10" bolts with STOCK 82 spring, one corner -> tire blow out. NICE! Had to ground the end of the spring and use small spacers. Tires were 255s. I had 275s on mine 10" bolts and stock spring, no issues. Weird!

Click to expand...

You know, there is a ton of weird shit like that with these sharks like the engine horns not lining up with the mounts on driver's side prying the tranny around on i'ts tail mount, then the issues with the floorboards need widening like my car had to have to fit even a 200 4r in there, much less a 700 then other guys don't have to do jack......then this ride height thing, then now your spring experience with it being asymetrical in some way, cutting one tire but not the other.....guys talking of the body being all crooked as hell on the chassis, without any apparent accident damage....

kinda like my old 70 Lemans/GTO convertible, pass rear fender was lower than the driver's side....never could figger out why I gave up and stuck a piece of plywood under the spring, hell with it....:waxer::flash::bomb:

I suspect they are, ask VS. From looking at the pics and having seen/used other springs those would be the ones i would go with. I have hypercoil springs (coil springs) on my cars and they are a great product, their service is top notch also.

Hyperco coil springs have a very good reputation on F-body message boards. They seem to have high quality products.

I had to put a 10" bolt on the passenger side and a 8" bolt on the drivers side to get equal fender lip to ground measurements on mine. I don't really want to have to drive it that way because I think it's an accident waiting to happen. Any ideas as to what the problem is. With 8" bolts on both sides adjusted the same, the passenger side is about 1-1/2" higher than the drivers side, but my half shafts are level. The drivers side height is perfect @ 27-1/2" but the passenger side @ 29" has this big gap between the tire and the fender lip. With the 10" bolt on the passenger side the car now sits perfect but the half shaft on that side is no longer level being higher out at the tire than it is in at the differential. I have a VB&P 360 lb spring and smart struts, any ideas? Could body mounts make this big of a difference in height?

glassbowtie77 said:

any ideas?

Click to expand...

When the half shafts are almost parallel that's where it needs to be. Maybe somebody replaced the fender and now it's too high ?? The body mounts can make a big difference, check #3 and #4 (in front of and behind the rear wheel) on both sides.

Also take measurements from floor to frame and see if it's levelled when the halfshafts are parallel.

From what your describing I'm 90% sure your body needs to be "adjusted"

Frame to ground measurements are the same all the way around, measuring from #2 and #3 on both sides. I also put a level on the frame rails on both sides and it is showing level from front to back as well. I would hope it is the body mounts, although I dread having to do them from what I've read.