126 Wheel Shake At Brake Above 65mph - PeachParts Mercedes-Benz Forum

1987420SEL · #1 06-25-2008, 11:31 PM

I searched but any close concern never seamed to be answered.

1987 420sel 90k started to develop what felt like a loose front wheel upon braking at speeds over 65mph. No pulsing in pedal just a violent wheel shake. I have tried and have even had several shops try to find issue and all come up blank. Car has new tie rod assy, center link, idler arm steering shock, thrust bushings, brembo rotors, oem pads, timken bearings, etc. Wheels have been swapped as have tires. They have been rebalanced 2x with zero change.

The car is perfect and rides like new unless over 65 and you hit the brakes. Sometimes it appears to subside but is apparantly worse after car sits in stop and go traffic.

Front rotors have .0025 on LF and .004 on RS of runout. I have tried every adjustment possible with the bearings to try and worsen or better the condition. It has zero effect. I even installed new Timken set again and set to proper specs. I have done with both gauge and by feel.

I have had car for years and is my favorite ride but I am looking to sell her and just do not want to push off on new buyer. I want it perfect so i can sleep at night.

What can cause a possible heat related shake? Or an issue that gets worse with heat as it does exist before hot just not as violent. The only issues that I have noted is the RF bearings are a bit tight to slide over the spindle but are loose once on and take adjustment fine. Also LF tire might lock up ever so quiocker than the RF. Tires are Michelin and were on car before problem developed. They have approx 5k.

ANY IDEAS????? THANKS

mbdoc · #2 06-26-2008, 08:02 AM

Most likely the brake rotors despite of the run-out that you measured.

scottmcphee · #3 09-10-2008, 02:34 PM

You didn't comment on the condition of your front shock absorbers. Wheel hop -> bad shock/s. From excessive wheel motion maybe your shocks are heating up and thinning out their damping effect?