CRX - Violent shaking under breaking

[bvondran]

All,
First time poster, but I've lurked here for a long time. I need some help.

I did a pdx this weekend at Nelson
Ledges and my car developed a violent shaking under light braking before the kink. It was an up and down oscillation, not a side to side shudder like warped discs. And it was violent at times, like I could see the dash oscillate up and down. There was a slight vibration under braking for 12, but nothing like before the kink.

The car is an 88 crx prepped for ita. New front pads (hawk dtc 60) and new front rotors. Rears are old and could be the culprit I guess.

What about ball joints or bushings, could they be causing such an issue? Or maybe the pads are cooling down too much?

Any help would be greatly appreciated.

Thanks,
Brian

Edited for additional description.

[Ed Funk]

I'd check shocks and CV joints.

[jumbojimbo]

I'd quit braking before the kink. And listen to Ed about possible causes.

[Tom Blaney]

I believe it could be a number of items but in order of importance I'd check

Lower Ball Joints
Radius Rod Bushings (yes I do make the best replacements)
Tie Rod Ends (but if it's up and down it's less likely)
Front Shock's for Bump setting then Rebound
Front Springs should be 500lb to 800lb rate depending on your driving style (with rears going from 750 to 1000 in proportion)
Upper Spring mounts (perhaps)

[tom91ita]

double check that the caliper mount bolts are tight. the two bolts that connect the caliper to the knuckle sometimes are not tight enough and can be loose.

[Knestis]

I had kink-related violent shaking but it happened after I misjudged a pass about dawn at the Longest Day, catching a slow car right at the apex. I lifted, went off backward driver's left, and didn't stop sliding in the wet grass until I was over the access road and down past the workers' station at the last turn onto the straight...



K