I am driving a 91 350SDL with 200K mi. Can anyone tell me what the proper procedure is for checking the front end? (tie rod end looseness, idler arm etc.) I believe I read somewhere (or perhaps it was a senior moment) that the inspection should not be done while the wheels are hanging down while the car is on a chassis lift.

Thank you, Noodles

To inspect those items put it on a lift or keep it on the ground and grab them and wiggle them from side to side and up and down. IF you have to much play then replace.

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1986 300SDL, 211K,Dealership serviced its whole life
1991 190E 2.6(120k)
1983 300D(300k)
1977 300D(211k)

Any play really. Look for torn boots and crack rubber.

I prefer to look if they are new and shiny parts

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Thank you both for you prompt replies. If I am interpreting correctly the wheels should be supported as if it were on the ground before checking for any play. My question is prompted by having the a State Inspection guy raising the car so that the front wheels were hanging free. He then proceeded to shake the wheels and concluded there was play in the tie rods. Logic tells me that when the wheels are hanging the front end is not in its natural position and is in fact stressing the ball jointed tie rod ends which in itself creates a false looseness that is not there. Do you concur?
Noodles

No he maybe quite right by shaking the tire. I believe if you have horizontal motion it is in need of new tierods, vertical is UCA. Someone correct me if I am wrong.

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http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

Horiz play indicates tie rods, center link, bushings, steering box and/or wheel bearings. However, I believe you must have the wheel and suspension hanging as if it where on a body/frame lift or have it jacked up by the body/frame points to check the vertical play. It woud help also that one of the front tires be on the ground to stabilize that half to the front end. This is not neccessary, but helpful for the untrained eye. If play shows up in the vertical direction - you should suspect ball joints and/or wheel bearings. Keep in mind that worn bushings could cause play in any direction. The best thing to do is get a buddy to do the wigling and you watch for the source of the slop. Pay attention to tie rod ends, ball joints, bushings, wheel bearings, and the steering box. Horizontal play typically means tie rod ends but could very well be a loose/worn steering box. When this is the case the pitman arm will wiggle, but the steering wheel shaft will NOT.
V

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80 300SD, 82 300SD (future drive train donor), 95 Cadillac Sedan Deville, 72 Chevy Fleetside w/Pontaic 400, 67 GTO (My First Car), 67 Austin Healey Sprite, 76 Chevy Farm Truck (Old Gold), Ford 8N, Farmall Cub, Some Chickens, a Dog, a Cat, and some Fish.

If you are not comfortable with checking this yourself I would highly recommend getting a 2nd opinion from an alignment shop. They would be better qualified to make that decision and or repair. If your inspection facility stated it would not pass inspection it is probably a safe bet you need some parts replaced.
As far as inspecting yourself the above advise is correct. Tie rods and other steering linkage parts can be evaluated no matter what position the wheel is in because the linkages flex with the suspension. Ball joints however are stressed during jacking and cannot be evaluated without support under the lower suspension.

Thank you all for taking the time to answer my question.
Noodles