Go Back   986 Forum - for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Performance and Technical chat

Reply
 
LinkBack Thread Tools Display Modes
Old 12-29-2008, 07:48 PM   #1
Registered User
 
Join Date: Jul 2008
Location: Michigan
Posts: 10
Nasty Shimmy and Shake...

I have a 99 Boxster with 30K miles. She has been absolutely perfect, until yesterday. Over 60 MPH, the car felt like it was a paint shaker. Anyone have any thoughts on what it is? I apologize if I should know this, but I am new to the site and new to owning a Porsche (6 months now). Thanks for any help.
randoodoo is offline   Reply With Quote
Old 12-29-2008, 10:19 PM   #2
Registered User
 
Join Date: May 2007
Location: California
Posts: 72
At the very least, go out and check your lug bolts. Also, you may have thrown some wheel weights - hit any potholes lately?

Can you isolate where it starts first?.... front, rear, etc.

good luck,

kj
Boxster44 is offline   Reply With Quote
Old 12-30-2008, 04:27 AM   #3
Registered User
 
Join Date: Sep 2006
Location: NEPA
Posts: 343
Quote:
Originally Posted by Boxster44
At the very least, go out and check your lug bolts. Also, you may have thrown some wheel weights - hit any potholes lately?

Can you isolate where it starts first?.... front, rear, etc.

good luck,

kj
The man is right about checking the lug nuts, but also check them for correct torque and not just to see if they are tight. Correct torque is imperative if you want a safe and wobble free ride. Ed
cvhs18472 is offline   Reply With Quote
Old 12-30-2008, 05:35 AM   #4
Registered User
 
Join Date: Jul 2008
Location: Michigan
Posts: 10
Thanks. Lug nuts are tight and wheel weights are there. I didn't check the torque. The shake is so bad it is hard to tell if it front or rear, but I'd guess rear.
randoodoo is offline   Reply With Quote
Old 12-30-2008, 06:35 AM   #5
Registered User
 
Join Date: Jul 2004
Location: Houston, Texas
Posts: 7,236
Just to rule out your wheels and tires, get them road force balanced on a Hunter 9700 series machine. Many Discount Tire shops have them, but some don't so ask. With this machine, they have the ability to see the heaviest part of the wheel and the lightest part of the tire and match them to make the unit more balanced without weights.

If after you've done this the car is still shaking like crazy, a Porsche mechanic (dealership or indy) needs to inspect the car and drive it. He can then tell you if one of your wheel bearings is shot or not, which can cause bad vibration. My car had a horrible vibration problem that I could never fix with wheel balancing. I changed out the wheel bearings all the way around and it rides like a brand new car now.

These are the things that spin and cause vibration at speed. Another thing to check is your motor mounts, but frankly, they degrade over time and don't crap out on you overnight like what you are describing.

If it's a bearing, you should find a good indy shop to do the work for you. The dealership will rape you. The part is only $50 but the book rate for labor is something like 4-6 hours. An indy might just charge you actual time.
__________________
'97 Boxster (Black Hole for 42,000 Dead Presidents and counting) - 122k
New motor, transmission, suspension, and on and on and on it goes...
RandallNeighbour is offline   Reply With Quote
Old 12-30-2008, 08:17 AM   #6
Registered User
 
Join Date: Jul 2008
Location: Michigan
Posts: 10
Great tip. Thanks. I might just swap the wheel bearings as you suggested. I have new Sumi's coming this week and I'll see if they use the Hunter. I have heard from many people that the Hunter is the best way to balance. I'll advise later this week if that worked. Thanks to all. This is a really great site and everyone is extremely helpful.
randoodoo is offline   Reply With Quote
Old 12-30-2008, 09:03 AM   #7
Registered User
 
Join Date: May 2007
Location: California
Posts: 72
I suppose a wheel bearing could be the culprit, but that would have to be one bad bearing (and you'd probably be hearing a drone or dull whirring sound).... as a sanity check before anymore freeway driving, jack up each corner and grab the top and bottom of each tire and push/pull hard to see if you can detect any play from the hub (also known as 'wheel bearing carrier').


good luck,

kj
Boxster44 is offline   Reply With Quote
Old 12-30-2008, 09:32 AM   #8
Registered User
 
Join Date: Jul 2008
Location: Michigan
Posts: 10
Unhappy

Ah ha! I couldn't tell by the way I was parked before, but now I see the OBVIOUS problem. My PS Rear Tire is canted about 5 degrees toward the top. Something broke... Great! I'm sure it will be inexpensive. (sarcasm)
randoodoo is offline   Reply With Quote
Old 12-30-2008, 09:38 AM   #9
Registered User
 
Join Date: May 2007
Location: California
Posts: 72
It'll depend on which link "may" be broken.... possibly an eccentric adjustment has come loose and a realignment may be all that's needed - hope for the best.

If it's a link, it should be pretty straight forward to replace and realign.


kj
Boxster44 is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -8. The time now is 04:06 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page