Shakin 94 Coupe

[DaleB]

Howdy Folks

My old 94 coupe rides fine on the highway (up to 134 smooth as glass), but when I take the top off, it takes two men and a boy just to hold on to the steering wheel it shakes so bad. I put some new Bilstein shocks on today, but I think I wasted my time, as well as money. I couldn't find anything wrong with the old ones.

Anyone got any suggestions? I'd appreciate any guidance, or maybe direction where I might get an answer.

Thanks - I might also add that I am so mechanically inclined that it took me 6+ hours to put on just the front shocks. Hard work with a pair of pliers and a screwdriver.

Dale:confused

 

[Ken]

...but when I take the top off, it takes two men and a boy just to hold on to the steering wheel it shakes so bad.

Howdy Dale, are you sure you not exagerating just a wee bit?

I can't think of a reason for such excessive shake with just the roof removed. Is it a ***** to remove when you DO take it off and put back on? If that is the case, then that would only affect the windshield frame I would think, and not the handling. But I guess you never know. :eyerole

Does it shake severely over smooth as well as rough road surfaces? :confused

_ken

 

[DaleB]

Howdy Ken

Us Texans have been accused of telling some Tall Tales, but this one is truly strange.

We have experimented over different roads, and different parts of town, but still shakes like a half empty beer can tied to the back of a newlyweds pick'em up truck. The new shocks did help somewhat the normal driving but I'm afraid to take the top off again, but will tomorrow. I thought maybe the wind shifted the balance of the machine, but what the heck, what does a Texan with his head tuck in the clouds, his feet on two continents and nose the size of Mississippi, know about a Vette anyhow?

Whatever it is, it probably only happens to me. But we still enjoy the drive.

Cheers!

Dale

 

[John-C5]

Howdy Dale

I've been a guest at the site quite frequently since I picked up my first vette a couple months ago. When I saw your post I had to register so I could reply. I’ve experienced the same problem. First time I took the top off I couldn’t figure what I out what was going on. Since then I’ve had the tires balances, the car aligned and replaced the front shocks. It’s much better, no problem on smooth roads, but it still feels a little strange on a rough road with the top off.

I thought for sure it was only happening to me also, nice to know I’m not alone.

Enjoy your ride, I know I am and I’ve spent a lot on time driving it in the last two months.

John

 

[Tanzanite3]

Our experience is all good.

Hey guys... sorry to hear about the shakes!!
Luckily for us.. ours is smooth as can be expected. Top on or off!!
Just windy as heck. 'bout blows yer ears off!
Oh yeah.. the main reason I got in here is to welcome a lurker!
Hey John-C4... welcome to the CACC.. best there is anywhere on the web.. Great friendly folks!!

 

[Patti]

Welcome to the forum, JohnC4....glad you came out of lurkdom. I don't have any advice for the shaking when the top is off, except
to mention keeping the top on. Congratulations on your first vette.


Patti

 

[Ken]

Hey guys, that is not an unusual occurence for the car to squeak and shake with the top removed. They did upgrade the chassis with the convertible-inspired structural member for the coupes, but the C4s, especially the older ones, all wind up suffering from the shimmy and shakes after time.

One thing that has seemed to reinforced my C4 was the addition of the Cross Bar from R-D Racing. (You can find that link in our Corvette Portal.) I have yet to meet Dave face-to-face, but he certainly goes out of his way to take care of you.

Check it out, it might be the fix you're looking for.

_ken

 

[Eric]

Howdy John-C4, welcome to the CAC! Nice to see a converted lurker on board.

 

[Rob]

Not sure how I missed this thread. One of the inherent quirks of the C4 chassis is that it's prone to flexing. It's not too apparent with the roof panel on, but becomes so when the panel is removed.

Part of the reason the flex occurs is because the roof panel is actually a very important support member so to speak. When you remove it, you remove that extra support. This is the reason why if you've noticed in the past, if the car is not parked on level ground and you try to put the roof panel back on, you either won't get it back on , or you'll have a difficult time getting it on. Same with the hood. The hood may be difficult to latch if the car is not parked on level ground. Again this is due to chassis flex.

It is however, less noticeable in the later models (in my humble opinion. My '90 flexes quite a bit with the roof panel off. I drove a '96 Collector's Edition with the roof off a couple years ago and was amazed that it was as solid as my '90 with the roof panel on. 6 years of refinement definitely paid off.

 

[Rob]

I actually can't say. I've never spent enough time in a C4 convertible to really say. I've heard that the convertible is just as susceptible as the coupe to chassis flex.

 

[vms4evr]

Rob hit the nail right on the head :bang
My92 is a little shakey on rough roads with the top off. You feel even more vibration through the steering if your wheels need re-balancing. It's annoying but not terrible.
As I understand it what Rob says is correct. The C4 design makes the whole car body integrated and acts like it is part of the frame. Seeing as how the car doesn't truly have a full frame. So if you pop the top then you break the unitized body in one section. That will allow it much more flex than it normally has.
Where I work they implemented speed bumps, only they're more like speed mountains... My whole car fits on the damn thing! Go over that with top off and the body will really flex
Graham

 

[Ken]

When ya love 'em, ya learn to live with 'em.

_ken

 

[Ken]

Hey, Cowboy Dale! Did you happen to see these on shaking and rattling?

Shake, Rattle but no roll yet...

Shake, rattle, & roll update

_ken

 

[DaleB]

Shaken Shaken Shaken

I didn't know there were so many of us. Just might start a new dance craze. Do we syncronize the shakes or free shake?

I am dropping by Bowling Green tomorrow, so the wife said might as well pick up a new one. Right! as soon as I hit the Lottery. I had to sell my eyeballs to get the 94. I still get confused on new roads with a co-pilot telling me which way to turn and how much to turn the wheels. Kind of nerve wracking. I am learning the sounds of new car horns.

Safety alert for the day. If your traveling between San Antonio and Bowling Green, LOOK OUT.

Be Cool, Be Careful, AND HAVE FUN.

Dale :J

 

[Ken]

Re: Shaken Shaken Shaken

I had to sell my eyeballs to get the 94.

:J I got it! :J

:L Remember "Hoot" Gibson? Well, Dale, I think "YOU'RE A HOOT!" :L

_ken

 

[John-C5]

Hey fellow CACC members, thanks for the warm welcome. Didn’t know it was a crime to be a lurker.

I’m getting some really great feed back on my shaking problem, being my first vette I suspected it was somewhat normal when you remove part of the body but it’s nice to know it is. You’re right on about the hood and roof adding to the stiffness of the body. I found that I had a loose hood hinge. I could move the front of the hood up and down about 1/8 inch when the rubber bumpers were backed off. Replacing the hinge cured some squeaks and rattles in the front and makes the car drive better. Guess it just a lot of little things that add up as the car gets older.

Ken, thanks for the tip. The Cross Bar from A-D Racing may be just what I’m looking for to stiffen her up a bit.

John