Guybrush Wilkinson

What would be the life expectancy of original 996TT suspension? At which mileage have you aquired new shocks because the originals have become soft / wobbly?

Dock

Are you seeing something that doesn't seem right in the way your car drives?

haulinkraut

Great question! I would also like to hear from anybody replacing control arms, shocks or springs due to wear or other failures.

SSST

It probably has a lot to do with how the car has been driven.

Macster

Life expectancy of the suspension depends upon several things. Hard to say what one will get.

My 03 Turbo with nearly 66K miles on the clock still feels nice and tight.

My 02 Boxster with over 242K miles on its clock doesn't feel quite so nice and tight. But the car still stays on the road and stays planted through corners even if the pavement's rough.

The rubber suspension bushings will likely need replacing before the shocks.

I was told if the shock isn't leaking no need to replace it.

You can 'test' the suspension some. Use your hands with your body weight behind them to push down on the car's corner then release and repeat at a rate the gets the car's corner moving up and down, from the spring's natural frequency (?). Then stop.

If the bouncing continues any at all the shock is suspect. If you can get away with it try this on several cars to develop a feel for how fresh shocks react and how shocks with more miles on them react.

Do this test at all 4 corners.

If you find a corner than continues to move up and down any more than the rest or any more then a newer car you've found a questionable shock. (This test doesn't mean squat if the shock is leaking or there are other signs of shock trouble. But shock trouble is rare.)

Then the question becomes whether to replace just the bad one, both on that end of the car or all 4. I'd probably at least replace both on that end of the car.

Sincerely,

Macster.

haulinkraut

I agree. And alot can be learned from other's personal experiences. Hopefully whoever shares here can also share their driving background (ie track driving, drag racing or agressive street driving).

Dock

Have you tried that on your Turbo? Even before I installed X73 suspension on my Turbo, there wasn't any way to get any corner to move up and down using the technique you described...the springs were way too stiff.

Mikelly

If you get a copy of the FSM and take a look at the bits associated with the upper spring mount/perch/bearing assembly, you'll see that it might not be uncommon to see wear on a car that's been driven for any appreciable mileage. These cars are heavy and I'd expect a suspension rebuild at around 50K miles... Will you need Struts? Probably not, but I'd expect other bits and pieces... Especially motor mounts and other rubber bushins... Def. should get an inspection on them...

And before the great debaters come out of the wood work, I'm basing this SOLELY on what I've seen first hand on other members cars at my shop. This is ONLY my experience and I am quite certain that others mileage may vary.
Mike

Guybrush Wilkinson

My car has 45.000 miles. The front seems a bit soft on our bumpy roads. I am not quite sure though, I just traded in my Carrera 2 which had the front even softier.

As an active snow cross and enduro ethusiast I do a lot of adjustments with shocks according to different riding conditions. The front of my Turbo feels like the rebound damping is not what it could be. Also the car nods quite deep some times.

On curves - when there is no bumps, the car goes perfectly. No tilting. Also, suspension, bushings, arms etc do not make any sound.

Mikelly

Get the car in the air and inspect the front struts for any signs of seal failure on the strut assembly. If you feel the car is blowing through it's dampeninng then there may well be an issue with the strut.

Mike

Macster

Not that I can recall. I've done it to the Boxster a couple of times.

I don't have the Turbo handy right now to try this but later today I think I'll give it a try and see if the bouncy test can actually be performed on the Turbo.

Added: It just occurred to me though that if the bouncy test 'works' that could be a sign the shocks are in need of replacement.

Sincerely,

Macster.

fedmax

I now have 80'000 miles on my 2002 turbo suspension still fine (road car no racetrack)

Guybrush Wilkinson

Macster, your test will be good info for me. I just did the bouncy test on my original front suspension. No bouncing. When I press down sharply using the weight of my upper body, the front of the car dips down about an inch. I weigh 165 lbs.

I opened the front compartment lid and pressed down on the center of the front bumper.

How does my inch compare to yours? Does my inch mean the front shocks have seen the best days?

Dock

What you are doing is just compressing your front springs. To check for shock dampening you have to set up a brief up/down cycle by compressing your springs, letting them release, compressing them again as they reach the top of their travel...doing this several times until there is some inertia built up. When you stop the manual compression the "shock check" is seeing how long the up/down cycle continues. This technique works when someone can actually compress a car's springs enough to start an up/down cycle. I don't believe you can get any cycle going with only an inch of spring compression. That was my point when I opined that the Turbo's springs are too stiff for this type of shock test.

Macster

What Dock said.

The bouncy test may not work with the Turbo. I haven't had a chance to try it. Some personal business came up unexpectedly and because this required me to drive all over this area I decided to park the Turbo and have been driving the Boxster. I was going to pick up the Turbo today but rain came in and I decided not to risk the Turbo on the road with all these lousy CA drivers who can't drive in the dry let alone in the wet.

Anyhow, chances are as long as your car's shocks are not leaking or showing any other signs of trouble, making any noises, they're ok.

Modern shocks are pretty good. The Porsche shocks I think are over engineered for the usage we give them. Remember these cars are designed to run at high speeds on all kinds of roads (smooth highways, mountain roads, and rough secondary roads) for long period of times and most of our driving doesn't push the car or make that many demands on the shocks. Even with other makes of cars, I can't recall the last time I replaced a shock on any car I have owned and I've put some big miles on some cars.

Oh, I will say I have seen the front of the Turbo subjected to a bounce like test, when the car was on the alignment rack the tech after making some adjustments under the front of the car would reach up and grab some steering/suspension arms and pull the car down and then push it up and do this several times and get the car's nose bobbing up and down to I guess settle the suspension/steering after making the adjustments. The car stopped moving as soon as the tech stopped exerting any force on the car.

Sincerely,

Macster.