Scuttle/Cowl Shake after new suspension

[FunElan]

Hi all - finally got some canyon miles on the M100 on a nice day in Los Angeles. I've only driven it really on the highway and around town. Noticing that over "rougher" terrain (meaning, not smooth like glass) and certain bumps, I get a fair amount of shake in the cabin. I can keep my hand on the a pillar and feel it wiggle back and forth. Normally I'd accept this as part of owning a convertible, but the M100 is supposed to be fairly rigid!

All suspension is brand new (less than 300 miles) save for rear wishbone bushes. The car was aligned, corner balanced, and ride height set close to factory. I have GAZ struts, currently turned all the way down (full soft). My only thought is to increase the GAZ damping, but I can't help but feel like it would make things worse?

Perhaps I need more miles for the bushings to settle? Curious what you all think.

Thanks!

[Tuga2112]

its free to adjust the struts.

my car is a hell lot more shaky/rattly after i changed the springs and dampers. a few years ago

my GAZ struts are set 2 clicks softer from the middle point. i found that to be the softest setting where the nose didnt dive too much when braking. i need to have another go at setting it after a year and new tires. i need to set the geometry and get that re-adjusted.

i suggest start by making them stiffer. just to find out what happens.

[RonR]

Do the GAZ struts come with Poly top bushes?

Since fitting front AVOs a while back my car handles well but feels a bit shaky over uneven road surfaces - The struts came with Poly top bushes, which might be the culprit.
I think what's happening is that any small wheel movement isn't being fully damped by the bushes and is being transmitted into the chassis.
I'm going to re-fit some rubber top bushes to see if it makes a difference.

[FunElan]

its free to adjust the struts.

my car is a hell lot more shaky/rattly after i changed the springs and dampers. a few years ago

my GAZ struts are set 2 clicks softer from the middle point. i found that to be the softest setting where the nose didnt dive too much when braking. i need to have another go at setting it after a year and new tires. i need to set the geometry and get that re-adjusted.

i suggest start by making them stiffer. just to find out what happens.

I think the added "stiffening" of just having new stuff is definitely contributing. I'll stiffen the dampers a tiny bit and see if it changes, but they're already set to full flaccid which I would assume would be the best setting for this....

Do the GAZ struts come with Poly top bushes?

Since fitting front AVOs a while back my car handles well but feels a bit shaky over uneven road surfaces - The struts came with Poly top bushes, which might be the culprit.
I think what's happening is that any small wheel movement isn't being fully damped by the bushes and is being transmitted into the chassis.
I'm going to re-fit some rubber top bushes to see if it makes a difference.

Hi Ron - they actually have rubber on the top, poly on the bottom, that is, if I assume what you're talking about is the rubber cup bushings on either side of the strut top. They're nipped up tight with a small nylock.

The bottom of the GAZ I have bolted to a poly bush in the control arm (with those funny arms that make room for the axle to go through). So I have a rod end for an endlink, and the poly bush with a bolt going through, securing both the strut bottom and the sway bar.

Rear GAZ have a poly bush at the bottom.

[Tuga2112]

I think the added "stiffening" of just having new stuff is definitely contributing. I'll stiffen the dampers a tiny bit and see if it changes, but they're already set to full flaccid which I would assume would be the best setting for this....

my thinking is.. .

maybe its too soft. and its reaching the end of its travel. making the end of that movement a complemtely "un-dampened" vibration.

as i said. its free. and worth go