Idler Arm Question - PeachParts Mercedes-Benz Forum

tobybul · #1 04-15-2010, 02:37 PM

What does the ideler arm do and what are the symptom(s) if the idler arm needs work or replacement? Thanks

rrgrassi · #2 04-15-2010, 03:11 PM

It works in conjunction with the pitman arm, allowing the tie assembly to move.

If the Idler has any lateral play in it, in needs to be rebuilt or replaced.

I had one go bad on an old Pontiac. Steering was affected a bit, but I could hear it rattle. It rattles like a failing tie rod. I'm sure a total failure can cause a really bad accident.

tobybul · #3 04-15-2010, 03:20 PM

I noticed on my 84D that something is 'clicking' down there when I make either right or left turns. Could that be the idler arm? Will using the idler arm bushing repair kit correct that?

rrgrassi · #4 04-15-2010, 03:30 PM

It can be. You need to get under it and check it out.

Bad bushings can cause that and the repair kit should fix it.

Stevo · #5 04-15-2010, 06:57 PM

The one I replaced made a loud "creaking/groaning sound when the wheel was turned. An easy, quick, cheap, job

pawoSD · #6 04-15-2010, 07:00 PM

Quote:

Originally Posted by tobybul

I noticed on my 84D that something is 'clicking' down there when I make either right or left turns. Could that be the idler arm? Will using the idler arm bushing repair kit correct that?

Bad idler arm (bushings) can cause steering play, vibration while driving, and groaning noises when turning the wheel. I recently replaced it on our W201 and W124, and it makes a difference.

Essentially what needs to be replaced is a bolt, and two rubber bushings with a metal tube inside them....the arm itself is just a giant piece of steel, doesn't really wear out.

patbob · #7 04-15-2010, 07:36 PM

The arm keeps both front wheels pointing the same direction by keeping the parallogram geomery identical on both sides. When the bushing wears, the geonetry doesn't stay identical and will shift around. That will cause the passenger wheel to be able to turn a few degrees left and right independently of the steering wheel and drivers wheel.

You'll almost never notice it as a steering problem unless you go over some ridge in the road that's nearly (but not exactly) parallel to your direction of travel and only on the passenger side. When the front passenger tire hits it, it might turn a few degrees and cause the car to veer slightly left or right.

Other than that, you'll probably only notice it as increased tire wear and noise. If it gets extreme, you might notice it as an alignment problem that changes.

When you get it fixed, ridges in the road like I described will not cause the car to veer at all, even a little bit.

YMMV, but that's what I discovered/learned/deduced when I noticed my car would veer when I drove (slowly -- <5MPH) over a part of a road where the asphalt had delaminated near the curb.

layback40 · #8 04-15-2010, 09:16 PM

Its very easy to put the kit in. Have done it 2x. makes the car stop wondering when its going in a straight line.

tobybul · #9 04-17-2010, 06:15 PM

Well, as it turns out I believe my steering gearbox is the one causing the clicking. I adjusted it a bit and the clicking is somewhat reduced. I may have to adjust it some more. Looked like the idler arm was good n tight.

pawoSD · #10 04-17-2010, 06:38 PM

Clicking might mean internal issues with the box....also, it is hard to tell if the idler arm is in good shape unless the tie rods have been disconnected from it, only then can you tell if it is loose or has much play...even a small amount can cause vibration...