After having new tires installed, I begin now to notice clicking sounds coming from what sounds like the passenger side rear tire, which varies in frequency by speed; ive checked the tires to see if a rock got lodged in the treads, but noting seems there...any suggestions?

Had the same thing on front tire this summer - sounds like hitting joint in the road -but there are no joints. Turned out to be tread separation in the tire. The faster you go the more pronounced the clicking as the tread slaps against the tire core. Only give-a-way was there was a slight bulge in tire tread about 10" long making the tire slightly out of round. Have your rear tires checked. Only suggestion I have.

while the car is up on the lift you may also wish to check the balancing weights on the inside of the wheels

often times, tape weights barely clear the brake caliper and emit a clicking sound as they lack clearance and strike the caliper as they go around

this can be remedied by different (thinner) tape weights or by hammering down those currently installed

- - this is also a good opportunity to check the drive shaft bushing(s)

good luck and let us know how it turns out
-fad

I had a similar problem one time. The front wheel on my 300e had the "Kleen Wheel" Dust shields, (which keep the brake dust from getting on the wheels), anyway, the dust shield was bent on the edge, just enough to let it hit the brake caliper as the wheel turned. The sound was very similar to a rock stuck in the tire. I hope this helps you find your problem.

Ken Yancey

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1987 300SDL
1990 300E
1989 300E
1986 300E
1981 300D
1983 240D