The car-nut

Could you please tell me what is the best way to test whether oneshould be replacing the rear shock absorbers?

I am aware of the conventional test that you push the car down and see how far it bounces back; however, I find the test to be rather subjective. In other words, I have tried on three different cars, and to me, they all seem OK. Nonetheless, I get a considerably loud clunk noise from the rear when I go over potholes on my 996. This noise is nothing like loose ball joint, etc.
Cheers
Farid

Jason @ Paragon Products

A shock dyno is what you really need but if your 996 is still on it's stock struts and shocks there's a good chance you're in need of some new suspension. You may also want to check your sway bar bushings as they are frequently the source of noise when they wear and fail.

DBJoe996

Stepping aside from the conventional test, the first step is a visual check of the rear suspension components. Jack up the car, remove the wheels and visually check the struts, strut bushings, rear suspension bushings and sway bar bushings. Signs of oil weeping or leaking from the strut is a good sign they are in need of replacement. Worn sway bar bushings are obvious. A clunk from the rear when you hit a pothole tells me you probably need to replace the rear shocks. Always replace both. My two cents....

alpine003

+996

Shocks gradually wear so even if you don't have a complete failure, you're probably facing degraded performance. If they have any kind of miles north of 30k and you want maximum performance, I would just get new ones regardless.

Think of it as an incandescent bulb over time, it still lights up but not as bright. Gradual degradation.

If you'd rather go the inspection route first and do not have a shock dyno, you can at least check the pistons for any fluid leakage and also remove the shock and compress it to see if it springs back on its own.

CarlOrton

Alpine, you mention removing the shock to compress as a test.

Very newbie question here: (BTW, I have the Bentley manual on my Christmas list...) I *assumed* that all 4 corners of our cars were struts. Is it possible to replace just the shock portion without having to remove the strut and remove the coil spring? Full guilty disclaimer: due to life in general, I have not even jacked up the car yet to look underneath, other than what I could see laying on the ground.

mcbit

We do a shock dyno as part of the annual safety inspection over and it definitely shows degradation with time irrespective of visible signs of damage.

Ahsai

Just replace them. They are due for the cars of our age/mileage anyway. Removing them to test will be the same labor as replacing them so you may as well replace them with RoW M030 or Bilstein B6/8, etc (from Carnewal).

alpine003

Sorry for the confusion, shocks and struts are often used these days interchangeably. You will have to compress the springs and remove them to replace the shock(strut) on any of the 4 corners for this car.

I agree with this personally but I know there are guys with the other mentality. These guys are the same guys riding around with old worn out engine mounts too.

The car-nut

Thank you all for you input.
I just got but the 996; so, since the shocks are reasonably expensive, and did not know whether they had ever been changed or not, I wanted to do some test. However, given the fact that the engine is riding on the rear "struts" on these cars, I think, I am going to bite the bullet and replace them.

Thanks again!
Farid