240 Violent wheel shaking on braking

I think I know what needs to be done but I wanted to check for either confirmation or additional items to look for.
Relevant information:
1993 245 B230F
BNE Camber plates -1 degree camber
Caster 0
Polyurethane control arm bushings.
DIY coil over with 400#/in and luxe steer
BNE quick steer roll correction
BNE adjustable swaybar link
IPD swaybar
Cadillac calipers and v70R 330mm rotors

I replaced the rack 4 years ago because of heavy shuddering during turning and again two years ago for the same reason, both from Jorgen Automotive. Starting around two months ago the steering wheel would shudder while braking from anything above 40mph. Starting a couple weeks ago the shaking became progressively worse. As of yesterday and today it has become violent shaking to the point where I should not be driving it. This morning there was a distinct clunk in the front end during severe shaking and the severity decreased.

I have had the car up on jack stands and checked the torque on all the bushing bolts, looked for play in the ball joints, outer tie rods, checked torque on the quick steer roll correction to strut and all bolts are torqued properly.

Is it time for another steering rack and or a replacement inner tie rod? Are there other possibilities that should be checked?

Thank you all.

Ball joint seated in it's holder?

When I had the car on jack stands and jacked up on each ball joint I did not see any play, but then I did not jack up the hub to see if the two separate. I will investigate when I get home.

Also make sure that the rear poly bushing isn't torn. That's happened on 2 different cars and they would get a nice "clunk" under braking.

Sounds like warped rotors to me

culberro said:

Also make sure that the rear poly bushing isn't torn. That's happened on 2 different cars and they would get a nice "clunk" under braking.

Click to expand...

Didn't even think that was possible, it is so captive, but I will look.

VB242 said:

Sounds like warped rotors to me

Click to expand...

The passenger side rotor never felt quite right so I will check it, too bad I do not have access to my dial gauges right now. Could a warped rotor be the only source to the issue or just compounding other issues?

Bad rotors. If it only happens under braking. My wife's car is starting to do that. Got new rotors and pads and I will cross drill them and install when we get back from vacation. All of our [4 240 wagons] have cross drilled rotors, I have had good results doing this, the biggest problem is living in the northeast and the salt that they use on the roads in winter rusts them out.

Starting yesterday I do get a slight shudder on low speed turns but otherwise do not notice shaking under normal driving.

Sounds like warped rotors

I use a machine that cuts the rotors when still on the car. Rotors don't warp. It's called lateral run out.

Add me to the rotor list. First hand experience of exactly what you're describing. Could be a couple things. Might be pad material buildup on the rotor causing a thickness variation, could be runout on the rotor, could be runout on the hub, could be uneven torque on the wheel or the adapter if you have adapters.

In my case any moderate to heavy braking would really shake the wheel. Grabbed the dial indicator, found the LF was around .003, RF was .006. Played around with clocking and torque pattern and values, got both to around .001, stops smooth as butter now. Then I got new meats on the wheels, tire guys retorqued the adapters to xyz spec, the issue came back, so after fixing that, again, every visit I specify not to retorque the adapters.

Thanks everyone. I got a new set of rotors as a stop gap until we are moved and I have all my tools again. I will post back once I get them swapped out today if it ends up being the issue. So 6 thousandths is enough to mess things up sheesh. I have adapters. I was thinking about repacking the bearings while everything is apart. We will see how much time I have today.

ZVOLV said:

I use a machine that cuts the rotors when still on the car. Rotors don't warp. It's called lateral run out.

Click to expand...

To bad you are not in the bay area on the peninsula otherwise I would be visiting you.

Try rotating your tires to see if one is out of round or balance.

Typical max runout is around .003-.004" for most rotors these days.

Wire wheel the hub to knock off any rust or any chance of the surface being uneven.

Before pulling the wheel, pull it from the top and sides to check for play in the balljoint, bearing, or tie rod ends.

I do the above whenever I put a car in the air. Usually on the way up, during an oil change. Inspect pads at the same time.

I had the same issue, new rotors fixed it.

To add to the chorus: replace rotors (and pads).

Lateral run out is the winner! You can see the variation in the coloring on the back of the rotor. When I was checking it I could see a slight variation in the width of light between the pad and the rotor.

More importantly, also figured out the reason for the lateral run out problem. When I rotated the hub without the caliper, rotor or adapter it was extremely crunchy. That cannot be good. Take off the hub and I see this.




Quick run to OReilly's for the 3rd time in 3 days and pick up a new outer bearing National brand. Throw it all back together, new rotors and pads. cheap stuff from OReilly's, and back in business.



Drove it around the block and did a few hard brakes from 40 to 10 and it felt nice and smooth. Thank you all for pointing me in the right direction

Don't over torque your lug nuts.

85 ft-lbs with a torque wrench. Changed the oil and rotated the tires while it was up in the air as well.