First poorstylishman, what does and where is the idler arm do. It is a pivot that connects the left side steering to the right, coming from the right wheel the tie rod goes to the idler arm, then at another point on the arm the drag link connects and crosses under the motor to the left side, the bushing is what usually goes bad causing wheel shimmy. I recently rebuilt mine and was both surprised and relieved that the bushing and bolt could be replaced rather than having to change out the entire arm (at more expense I'm sure). I am by no means an auto tech but have turned enough wrenches in my time and yes many times the various manuals don't quite cover what you are looking for. I hope that this helps answer your questions.

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1991 300SE (my ride, 279,000 miles, looks almost new
1954 Cadillac (21 yo son's car, he bought when age 15)
1972 SeaBird 19 ft runabout (old but solid, slant six, Volvo sterndrive perfect condition, undergoing complete overhaul and refit)
1998 Toyota Rav4 (my sons daily driver when he is in the Continental US, PROUDLY serving in US Navy)