87 300D Front end shudder when braking - tie rods?
 

I am still diagnosing various problems with my "new to me" 87 300D. One such problem is a front end shudder when braking, especially from faster speeds. If just slowing down from say 10 or 20 mph, it isn't very noticable, but when I slow down from 50mph, it is very noticable. Would worn tie rods cause this problem and is there anything else I should look at? I have detailed my troubleshooting steps taken so far below.

I suspected it was a brake rotor problem so I removed the front wheels this weekend and inspected the rotors. They checked out visually, no cracks, gouges, or other imperfections. I measured as best I could with my crappy micrometer and they were all within spec still at about 20mm. A very small lip on the edge of the rotors and the pads seemed to have worn evenly. I can't guarantee the rotors are good until I can get in there with a good brake micrometer.

I checked the rest of the front end components by moving and shaking them and the only thing I found that seemed abnormal were the tie rods. On both sides the boots were totally shredded and when I turned the wheel back and forth quickly, I got a clicking sound seemingly coming from the tie-rod ends. When I manually try to move the wheel, there doesn't appear to be excessive side to side play in the tierods, but there is some up and down play. I never noticed this before, but after putting the wheels back on and lowering the car, if I jerk the steering wheel back and forth I can here the clicking sound coming from the front end.

Thanks for any help for this novice mechanic,

Jeremy

Tie rods are only part of your problem, did you do a runout test, I'll bet you have warped rotors also.

OH, and while you are under it check the other dust boots on the Ball joints and center link too. If those are bad you should do them all at once. Alignments do cost quite a bit more than $10

runout test
 

In order to do a good runout test, do the rotors need to come out? I imagine there is some kind of device they need to be inserted into in order to keep the rotor and micrometer stationary while the rotor spins around.

J

Typically no. use a magnetic base with your dial guage. And slowly spin your rotors mounted on the car. You may have to pull your caliipers to check the backside. But first look for the obvious such as loose wheel bearing and worn Balljoints.

Your rotors are warped, either have them ground or replaced. They're not too expensive to replace or have turned. Don't turn them if it's been done to them before, but the machinist will tell you if they're too thin.
Thanks
David

Tie Rods and Drag links usually show vibration at higher speeds. My guess is warped rotors.

Check the ABS sensors, too -- if out of place, you could be having the ABS activate and that "pumps' the brake pedal.

Do both tie rods and the drag link, and buy a new steering damper too, you are due for all four. When the damper goes bad, the vibration batters the tie rod ends to death. Set new tie rods to the same overall length of the old ones and it will be close enough to drive to the alignment shop. Drag link isn't adjustable.

You will be stunned at the difference in handling when you replace this stuff, since you are currently darting all over the road.

When you get all that done, save your pennies for torque and thrust links in the back. Dollar to a donut, if you jack a rear wheel up off the ground and apply torque to a lug bolt, the wheel will move back and forth about an inch -- this means torque link (and probably camber and thrust link, too) are completely shot. Causes thumps under the rear seat on hard shifts, too.

Peter

While you're under there, you might as well get the idler arm bushings replaced too. Not much more cost and quite helpful.

Ken300D