So what's the deal?

Going to work and back, on a recently re-paved highway, my car feels "bouncy" in the suspension. I can feel it in the butt so I think that is the rear end no? It really gets going between 60-70mph. Feels like it's going to shake me and the car apart. It is not comfortable at all.

While it's doing this shake and bounce, if I take the "slack" out of the gear shift lever, it's moving back and forth with the frequency of the shake. Does that mean the engine and tranny are moving around also?

The car has:
New tires
New Bilsteins
New springs
New front wheel bearings
Engine and tranny mounts look good
New 4 wheel alignment

This issue is driving me nuts!!

Let me add... The car did this before all those things were replaced also.

Rusty:

Sounds like maybe the motor/transmission mounts ???

Have someone else put the car in 1st and take off fairly quick...You look underneath and see if the motor/trans moves before the car does...

Just make sure the person who is driving knows the difference between 1st and reverse...

2-OH!

Motor and trans mounts were my thoughts too. There's not really to much else to be wiggling around back there. It also could be your rear suspension console. Have you checked the trailing arm mounting ears for cracks? Most likely motor mounts though.

Do you have wheel spacers or adapters ??

Ball joints (new or old ?)


B

Thanks for the suggestions. I'll get someone to drive the car so I can take a look. I'll also get someone to drive behind me at speed and see if anything is jumping around.

No adapters or spacers.
Haven't changed ANY of the suspension bushings.

Suspension seems very stiff. Hardly moves if I push down on the bumpers.

Forgot to mention some other new parts:
New turbo tie-rods
New ball joints

Thanks.

hahahahaha, man, i nearly spit out my mouthful of lunch at the monitor when i saw that. first week after i got my 914, i was trying to back my 99 honda accord out of the drive way, couldnt figure out why car wont move backwards. thought i have the e-brake on or something, no, that wasnt it. dammit, whats wrong, tranny blew? unlikely, car is only a few years old... took about 2 minutes to figure out i got 914-shifting-itis

Well, I just went snooping around the rear end of my car. Took out the rear shocks to take a look at my shocks and springs. While putting the wheel back on, I noticed a clunk. Turned out that the passengers inner trailing arm bolt was loose and I was getting some lateral play. Tightened it up and no more clunk. Haven't taken it for a test drive yet.


Does this seem like it could have been the problem? My thinking is that it could have been loose for quite some time or maybe the alignment guy loosened it for some reason and never torqued it down.

I bet you got it...

2-OH!

hopefully it didnt oval your suspension ear

One other thing I was wondering about. Could my suspension be too stiff for my tires? My tires are 195/65s on 4-bolt Fuchs. Could the sidewalls be that bouncy?

I thought my springs, bought used, were 100#. But now I'm thinking they are 180# progressives. What do you think? The wire diameter measured about .55".

Here's a photo.

I was thinking that too. I'm sure it didn't do it any favors.

Here's a close up of the springs. I thought the coils at the top were dead coils....

180's

Test drive it and report.
My first thought was as mentioned, trans mounts.
My shifter was dancing around too, and vibrations in the cab.

911 sport mounts fixed it all.

KT

Happy, happy, joy, joy!

Well that loose nut seemed to be it. Sheesh...that must be the only fastener I haven't touched. Car and shifter was not dancing around this morning. It was a very pleasant drive. A little stiff, but nice.