Crown Victoria (Police Interceptor) Shuddering

[AbusingTheMoog]

Posted this in the Ford section of the forum last week and haven't gotten any replies so I figured I'd post it here on Yank Motors.

Original Post:

Hey all,

Ive been having this problem with my Police Interceptor (2003 model); When I press the brakes at speed (30-45mph) the steering wheel shudders and the brake pedal vibrates quite a lot. My first thought was that the break rotors were warped, so I changed them to new vented rotors with new pads, and since I was doing the work I decided to change the wheel hub bearings at the same time (it was about time anyways, the car has 190,000miles on it), after four sets of bad bearings from the parts guy, I ended up buying the more expensive USA made bearings and they are perfect as far as I can tell (as well as a machinist friend of mine can tell). Now even after all of this work the shuddering is still there and it is still only happening during breaking. While I was doing the repair work I checked the suspension and bushings and everything appeared to be in order. My question is does anyone have any experience with a similar problem? And if so what was the remedy? Its driving me up a wall not knowing where this shuddering is coming from.

Thanks in advance,
- Matt

[chevy-stu]

Had this on my old IROC Camaro, new discs pads, track ends & bushes fine,turned out to be worn ball joints....

[redvictor]

It's in your suspension if you've checked run out of your discs. Usually it's the control arm bushes(stops the wheel going backwards and forwards under braking) but it can be you upper/lower arm bushes,front subframe bushes,ball joints,steering rack,tie rod ends etc. You need to jack the car up so as to take the weight of the suspension,get a big lever bar and try and move the suspension/steering to replicate what is happening. Either that or get the car on a 4 post ramp and do the same.
Hope this helps some.

[AbusingTheMoog]

Ahh good idea, I get it on a lift later this week hopefully and see what kind of play I can discern. I was leaning towards suspension but upon visual inspection the bushes looked pretty good almost new in some areas. But I'll take a look and see what I can find. Thanks for the info.

[AbusingTheMoog]

Haven't gotten the Vic on the lift yet, but I did have another look at the suspension and it looks like the passenger side from bottom ball joint bushing is crumbled and needs replacing. So it looks like its bushes, and Ill be replacing those soon.