Noisy suspension?
 

Whenever I go over bumps I hear a creak and a "thunk" noise coming from the back end of my car. What could this be? Does this mean my shocks and springs are worn out?

The shocks suck new but unless a mount is loose thats probably not what it is. There is a lot to squeak in these 4 link suspensions but I think the most common is prolly endlink.

mine does the same thing. im going to put my umi adj. phb on this weekend and replace my swaybar endlinks. and while i am under there im going to make sure everything is tight.

It's probably past due to take off, lube and retighten the
LCA and PHB and the sway bar bushings. All of these have
squeaked or banged on my car and it's plenty younger
than yours. I favor the graphite / moly engine assembly
lube you can get at auto parts stores. You may find the
PHB upper mount wants a big fat fender washer outside
it, for backing up the wimpy sheet metal tab. Mine spread
just from the hydraulic pressure of greasing through the
zerk fitting (aftermarket). My sway bar bushings creaked
when cold but a dab o' graphite goo fixed that up. All
fairly easy jackstand work. With the axle hanging you
can get an idea if there is any slop in the linkage.

I'm thinking about changing all my bushings with a master kit. I am more concerned about comfort and quiet than performance as I have a 150 mile round trip commute. Any recomendations on bushings? Energy Suspension? Performance Suspension Technology?
I'm driving a bone stock 1998 Z-28 with 165k miles.

Hello
Thanks for choosing UMI Performance! Like mentioned above! It is possible that your bushings in your rear suspension components are shot. I would suggest checking them and make sure all of the hardware is not only tight but also in good shape. That is why we offer control arms with grease able fittings. To allow you prolong the life of the bushing especially if the car is driven hard. They will hold up a lot better under pressure. Below is a link to show you what UMI Performance has to offer for stock replacements.

http://www.umiperformance.com/catalo...3qge8p1crspvr4

If you have any other questions feel free to ask! I will be glad to help.
Thanks
Brad :D

you just replied to a 2 year old post.

There is a post above it that could use that info.....

I've had my UMI LCAs and Panhard bar for about 3 years now and the bushings still look and feel brand new. I put a pump of grease in them every 5-6 months.