Once the odometer passed 35K miles, I noticed that my wife’s care was making some unusual noises and thumps when moving away from the curb, accelerating and sometimes in turns. This got quite annoying and there were no other indications of half-shaft/CV joint, wheel bearing, steering gear or other suspension problems.
I got underneath on the lower “H”, front mount/support assembly and checked for loose nuts/bolts and found nothing suspicious. Then I decided to check under the hood to see how loose the upper front cross-member-to-strut tower braces and sure-enough, the bolts seened quite loose (less that 30Ft/lb). I attempted to tighten them up, but one of the forward bolts stripped on me at less than 60 ft/lbs of torque. I removed the bolt, and re-tapped it to the next larger size. Then I went and did the same to the driver’s side bolts. After completion, the vibrations/noises/thumps (looseness/unstable steering) disappeared and the car felt almost like new. This was all in 2008 and had been problematic since 2006 or so. Last week I drove my wife’s car again and noticed that the problem seem to be back, so I checked the torque/re-tightened the bolts, which felt loose again, and the problems have again disappeared.
I don’t have a manual for the car and I don’t know what the torque spec is for those bolts, but I have mine around 50ft/lbs. I would guess the spec to be 40, maybe as height as 60. If you have a similar problem, you could try torqueing them down a little and drive the car; the change could be dramatic. I just got new tires/struts/alignment and the error they found on the caster (both front wheels were off) could be related as the strut-tower could move forward/backward slightly. This seems (to me) to confirm that those upper bolts, if loose, are the cause of the problem. Hope this helps. I would include a pic with the location of the bolts to check but I can't seem to upload an attachment.
If you know of any after-market products to improve this upper-front assembly, I would be happy to hear from you.
