The "twitching" could be a bent/broken spring or shock.
Or worse, it could be a damaged trailing arm, or that
axle/subframe thing... damage from getting hit?
Get it up on a lift, and while your at it check your front
suspension for any damage/wear, thing like control arms,
bushings, etc. Are you sure none of the rims are bent?
Also be sure to check for wheel bearing play.

Whenever I had suspension problems in the past with
other cars and it was hard to define/pinpoint the problem
I would drive the car harder to make the offending part
either make itself more evident, or break it. yes I am
insane, and don't always suggest this. But there is a method
to my madness. :evil:

 

Checked the tire pressures? I've had that twice, once was a shock and the other was a soft tire. Then again on a Jeep Grand Cherokee (rented from Hertz for a 5000 mile drive) that's standard strange handling.

 

Colin, I can't imagine it was damaged in the hit. It was a parking lot fender bender, and I've put 1500 miles on the car since then. The shaking from the tires at speed (which is always present at the given speeds, bumps or no) came about 2 weeks before I had the tires swapped. I got them swapped thinking they were out of balance. Only when I finally got the car back, not only was the shaking still there, but this new rear end twitch developed.
I think if any of the rims had been bent, they would have said something to me about it at the garage. They're usually pretty good like that. Though tomorrow's project will be to swap tires on the rear end, and visually inspect the rear suspension for any damage.

Geordie, that was actually the first thing that went through my head, so I checked and adjusted all tires to 37psi, ready for my first AutoX next weekend. However, if this twitching isn't gone by then, my car will be sitting in the parking lot the whole time.

I can't help but think that the speed-related shaking and the new twitching are somehow related.... :???: :nervous:

 

Colin, I can't imagine it was damaged in the hit. It was a parking lot fender bender... I think if any of the rims had been bent, they would have said something to me about it at the garage. They're usually pretty good like that. (

Are you sure they checked your rims?
And are you absolutely sure your suspension is okay?
You don't sound too sure.

It doen't take much of an impact, even at just 5 m.p.h. damage
can occur. Get it on a lift, with a good mechanic there too. :wink: [/b]

 

Well, the wheel came off, and to no one's surprise, here is what I saw...

Yummy shock fluid. Lots of it. Everywhere.

::sigh::

The other side is bone dry. I guess this is a sign that I need to get lowered...
And it's gonna have to happen before I get new brakes, which, as you can see, need it pretty badly. They still work, though, so they get the bump for now. :sad:

Like they always say... You've got to pay to play.

 

Yep, new suspension time... and those rotors are shot!

Jimmy

 

those rotors look horrendous. uke:

 

^^^^ what he said!

 

You'd think those were the wrong pads, it's obvious they used to contact the whole surface in the past. Were the wrong pads put on? Both the shocks and the brakes are a safety issue. I'd agree with your priorities but since I do my own brakes I'd fix those today. Now. Rear shocks are very easy too, even if you do them before the full suspension job.

 

I took a quick look at my back disk. This is on a B5.5, but surely the swept area should look the same. The rust colored strip on my disk is only a few mm wide.

Those rear disks almost look cracked, it looks like there are a couple of radial lines on them at the 9 and 1 o'clock positions on the picture. At vwparts.com they're $36 each, pads are $40 per set. You got $120 for your life :wink:

 

Ya, something's terribly wrong with those rotors... you need to fix them NOW.
They appear to be cracking from heat stress too...
I suspect someone has put the wrong pads on your calipers.
You need new shocks, rotors and pads. All are fairly inexpensive, and can be fixed at home.

Jimmy

 

You most likely had a part of the pad rip off in the above pic... you ouly have about 70% of the contact that you are supposed to. I'm guessing that the back side is clean.

 

I'm quite aware that my rotors are nearly dead, and the other side is about the same, too. And yes, it would seem like the wrong pads were put on, as both of the rear rotors look the same. I'll check tomorrow to see if the backsides are fully swept or not, but I suspect that they are not. Certainly not gonna do it tonight, I'm sick as a dog.

What's interesting, though, is that there is a substantial different in height between the swept and unswept areas of the rotor. I would say nearly .030". It would seem as though the car has been driven with this mismatch for quite some time. I can account for some, but not all of that driving.

And, to address the concerns of the rotors being cracked, those are most definitely pad material deposits. I took a very close look when I saw those, and that's definitely what they are. Not cracks.

I'll take another look and some more pics tomorrow.