agent325

I have a 04 C4s Cab with 60K miles. I've noticed lately my car has a very very harsh ride over moderately uneven surfaces, especially on the freeway when I’m up to speed.

The drive feels better when the road the super smooth, but just doesn’t feel right.

I know I need tires - as they are starting to crack a bit, but could tires cause all of this?

Are my shocks done?

RPMulli

I am guessing your tires are due for replacement. What is the tread depth? Also, ensure the tire pressures are good. I doubt that your suspension is getting tired with only 60k.

street rod

Install the new tires and alignment first and see if it fixes the issue.

SSST

If your tires are cracking, that is definitely affecting the ride and noise. Also, if your tires are cracking and you have tread left, you need to drive it more.

Just saying.

logray

Plus one to check for pressure, and if the tires are worn that can be a big factor.

white99c2

My 996 has 19's and I recently started a post about cupped tires and noise. On the advice of another member I raised the rear pressure to 40 and the fronts to 36. Today I added more air and made the rears 42 and the fronts 37. The car really does ride much more solid, no more BANGING when I hit a bump in the road and best of all the tire noise is down by probably 50%. I am amazed on the impact this has had.
My car had 17's on it until December and I had the pressure set the same way I did with the 17's and that was all wrong for the 19's.

Jacks911

1) If your tires are "cracking" they likely are old and hard. Did they come with the car when you bought it? I had the same problem when I purchased my 2000 C4 in 2010 and discovered the tires were nearly as old as the car. The PO had no doubt switched wheels and tires with another set that had sat in the garage for years when he got ready to sell. Check the Date Code on those hockey pucks!
2) I have been told that gas shocks can "go hard" if they leak the gas... not fluid. Had this confirmed on my 1998 Audi when one strut stiffened up - after 100,000 miles - a new set of Bilstein Sport struts fixed things very well.
3)May or may not be your issue but my 996 suffered a bent front strut after a meeting with a San Fransisco pothole and that gave the same result - a very "firm" ride. This also made thunking noises at low speed which lead to the diagnosis and ... again a new set of Struts - PSS9's this time.

Hurdigurdiman

For rubber to be cracking it has to be perishing or drying up. Get those tires changed pronto before you have a blow out at speed.

skiracer

Tires.

function12

Throw out the fat chicks.
But it could be tires too.

BruceP

Performance tires deteriorate rather abruptly at 5-6 years of age, regardless of treadwear. Might have a look at the date codes on your tires and see how old they are.

Replacement is expensive, obviously, but if they're aged out you might be amazed at the difference fresh rubber will make.

agent325

- Tires are from 2006, I am getting them replaced this weekend

- Tire pressue was a little low, I added a 5 lbs to the front, the drive is a little better

agent325

So replaced my cracked bridgestone SO2s from 2006 with New P Zeros. The Ride feels Much Much Better. Nothing like new shoes!!!

RPMulli

We told ya so!

Pac996

Great news. Tires are only a 6 year life span. I had some 1 year old bike tires go into cracking sidewalls from not riding for a year while on a trip and the bike just sat in the garage. Best to keep the tires exercised which keeps the rubbers chemicals spread throughout. Sitting doesn't allow the flexing to help spread the stuff that keeps the rubber good.