philadave19030

Hey guys I asked this question earlier in the month and I'm still puzzled. My car sits too high in the rear, it looks like whoever did the suspension put in the aftermarket trailing arm to spring bolts the ones that are about 8". With the nuts backed almost all the way to bottom the car still sits at almost 30" from ground to wheel well. The car does have aftermarket wheels, I'll provide the tire size as soon as I can; however, the tires are only about 25-26" tall which I'm told is too short. Anyway please look at the pics and tell me do I have the wrong rear spring installed which is causing the ride height, is it the tires/wheels or a combination of the two. Thanks a lot guys. Also in an unrelated issue yesterday I was driving the car and when I got into 2nd gear the transmission began to tick. Just like one of those prize wheels at the carnival. As soon as I change out of 2nd it stops. Any ideas? I was told a broken tooth because 2nd gear always whines. It's a Borg Warner T-10 out of a I believe a 78 Chevy can't tell which model car yet but it's the 903 aluminum case. Thanks guys.

MelWff

the nuts are supposed to be near the bottom of the bolts to lower the car. You currently have the nuts all the way to the top which raises the car.

Alan 71

Hi pd,
Pretty much all the info from your previous thread still applies.
Ride height and the space from the top of the tire to the wheel arch are a function of the height of the tire and the suspension components being used.
A longer than stock trailing-arm to spring bolt with the nut just fully threaded on to the bolt will lower the ride height, but it doesn't address the cause of the ride height you're seeing.
Loosen the nuts on your current bolts until there is just one full thread showing below the nut and then measure. (Drive car before measuring.)
Regards,
Alan

philadave19030

The pictures are from before I loosened the nuts. The rear tire size is 255/60r15. What I don't know is if the rear spring is correct.

MelWff

there is nothing wrong with the tire size
if the nuts, contrary to what your pictures show, have been adjusted all the way down and the car still sits too high, the spring is the issue. Nobody can tell from a picture like yours who made the spring or how stiff it is.
You have no current pictures with the nuts all the way down and the suspension settled by driving the car?

Alan 71

Hi Dave,
The Ride Height Dimension Chart is based on the car having a 27" tall tire. (F70-15)
The spring 'appears' to display characteristics that original springs had…….
ends curved up each end of each leaf except the longest, a taper cut into each side of each leaf extending about 2" into the leaf, two 'clipped' corners on the bottom (longest leaf).
Regards,
Alan

Hard to know what condition it's in from the photos.

philadave19030

Ok guys thanks I'll grab some pics tomorrow (I work nights) and post them up. I have a feeling the spring is probably an aftermarket one. The car has an older resto so possibly the previous owner put a aftermarket spring in and tried to compensate for it with the longer bolts. It seems like that makes the most sense. Thanks again guys I don't mean to be difficult.

gcusmano74

Those nuts need to be retained positively. The factory used a cotter pin and a castellated nut on a cross drilled bolt. VB&P used nylock nuts (9/16 NF). If they unscrew while you're driving, it will very quickly become way more exciting than you planned.
And, yes, to lower the car, run the nuts closer to the bottom of the bolts. The factory spec on the rear ride height requires that the difference in height between the inner and outer strut rod bolts be some certain amount. (about 2 inches, IIRC) But if you set it up so that the half shafts are horizontal with the car resting on it's wheels, you will be close enough. You may have to push the car back and forth a yard or two to settle the suspension after each adjustment..

bmans vette

I'd be concerned about those bolts in comparison to the rim/tire sidewall height.
If you have a complete rear blowout, there is not much that is going to stop the bolts from bottoming out on the road. And that will not be pretty. I'd want the rims to hit before the bolts did.

A taller tire (stock height like Alan said) would help.

Good luck figuring it out.

Be safe.

philadave19030

So I just looked the rear spring is the 9 leaf version and the trailing arm bolts are 8". Do you guys think since I don't have the spare tire and carrier that is where the extra height is coming from?

Alan 71

Hi D,
Not having the spare-tire and tire tub will affect the ride height, but just a little bit.
I believe I've read it takes a 100# to lower the car 1".
Do we know the front ride height? A car low in the front will sometimes be tilted up in the rear.
Can you post a photo of the entire rear suspension…. from tire to tire?
Regards,
Alan

philadave19030

Thanks for your help Alan unfortunately I've just left for work but I know the front sits at approx. 28". I need to measure the clearance at the gram rail under the doors. I just can't seem to figure out why the car would ride that high in the rear. If it helps at all the rear tire size is 255/60r15 and the front is 225/70r15. Thanks again

Alan 71

Hi pd,
Both fronts and rears are slightly taller than the original tires, but there's more going on than that.
Under 'normal' conditions the rear spring should have just the 'slightest' reverse curve to it, and the half shafts should be about level with the surface the car is sitting on.
Regards,
Alan

philadave19030

Could have anything to do with the body mounts?

Peterbuilt

Did you do this yet?

philadave19030

Yes the nuts have been beaches down to about 1/2" off the bottom of the bolts. I can't see how that remaining 1/2" would get me down almost 2". I'm just at wits end because I have no clue where to go from here. I don't wanna replace the tires if it's not necessary. However idk what else it could be if the spring is correct which it appears to be. Even though the spring is 9 leaf could it still be too stiff?

Peterbuilt

Maybe you do not have a stock spring.
Stock spring is 140 lbs.

See page 163 here:

https://gmheritagecenter.com/docs/gm...t-Corvette.pdf

philadave19030

Thanks for the info, I just don't know how to tell the spring rate of my spring and I don't just want to throw parts at it. I'll call ecklers tomorrow and see what they say

havesometo

I have read if the leaf spring was installed while the car was in the air and everything was tightened it can cause this problem. Try losing the nuts and bolts just a little at the differential. Then push the car forward then backwards a few feet then tighten the nuts and bolts and see if that helps.

'75

I read here not too long ago that the current replacement springs, while having the right amount of leaves, are made with thicker leaves and may cause the problem you are having.