Hello,
I don't know if this has to do with my suspension but I hope someone may be able to help.
On my 94 Z-28, I get a loose/wabble sound underneath when I drive over a road that has some minor dips in it. This DOES NOT happen when I hit a bump, or drive over a curve ect. ONLY when I drive over a road with some dips. Its like a wabbling sound of some sort. This sound does not occur on a flat road as well. Any suggestions out there please? What does this sound like it could be?
Thanks!
Jason

 

is there a vibration with the noise? thats a pretty general description so it could be one of many things. hard to respond to. off the top of my head i would look at the universal joints.

 

Hi Craby,
It's hard to explain without verbally making the sound but it 's like a shaking/loose wabbling sound underneath but I don't think its the suspension because it doesn't make that sound when I run over a curb, or bump, it only happens when I'm going say, 30mph's or higher on a road that has little "dips" in it. When I drive over the dips, it makes like a shaking/wabbling sound underneath, but only when I hit those dips. sometimes the road may have several dips in a length of road and it will make that wabbling/loose shaking sound until I hit smooth road again. The steering wheel DOES NOT shake, its more directed in the middle/back of the car from what I can feel. There is no vibration, only when I hit these types of uneven dips in the road, does this sound occur, and it can get pretty loud as it shakes.
What do you think? Did you ever hear of anything like this?
Thanks Again...
J

 

sure sounds like the rear universal joint is making itself known. is the car lowered? is the suspension stock? could be a failing u joint. or what can happen is if the bushings in the rear control arms and/or torque bar are worn the rearend will move allowing the front area where the u joint is to move up and down. this creates a condition where the shaft can be out of alignment to the point of vibrating. this will happen when the car body moves up and down like you are saying.

 

Thanks Craby,
I'm almost 100% sure its stock, its not lowered but it does have 17 inch tires on it.
I guess my concern is, is it safe to drive on and if I had a mechanic work on it, what do you think the cost of something like this would be range wise?
Thanks again for your help...
J

 

how wide are the tires? what offset are they? are you sure they are not rubbing?

 

Don't know the width and I'm pretty sure they are not rubbing. There is about a 2 inch gap from tire to frame. They are your standard 17inch tires..
THanks,
J

 

ok if they are no wider than 245 then you should be ok. my 245 45 17s would rub on the ouside but im lowered about a inch on back. does it make the noise when the car goes up or down on the bump? cost should not be that bad for a u joint install if thats what it is. when you move the car from reverse to forward are you feeling a clunck or bump. like the rearend is moving a bit?

 

Thanks Craby,
I tried it slow, hitting bumps and curbs, even reverse.
It only makes the sound when going around 30 mph's or higher on streets that have like small dips in them. It's only when I hit the dips, do you hear the waddle/loose shaking sound, its weird. I thought it may be the suspension at first but when you hit a real bump or pothole, that sound does NOT occur, only on a waving street. You can tell when the street flattens out, the sound goes away...
I know, weird but its VERY annoying when the sound occurs, it can get pretty loud...
J

 

yah it sure sounds like a universal. how about a couple pictures of the car.