What causes wear on the idler arms?

Dear Car Talk

Dear Car Talk | Mar 01, 1990

Dear Tom and Ray:

I keep noticing that my tires are wearing on the outside edge of the tread. I felt it was a matter of keeping the front end in alignment. However, at the Sears Auto Center, I am being told that the idler arms are wearing out, that they cost $200 to replace, and that the 1987 Chevrolet Astro Van has a problem with idler arms. The technician said they might only last about 11,000 miles. This sounds ridiculous to me. Have you heard of any such problems with 1987 Astro Vans?

RAY: Let's start from the beginning. The wear on the outside edge of the tires really is an alignment problem. Normally, a wheel alignment would be the solution. But what your mechanic is telling you is that he CAN'T align the wheels because the idler arms are worn out.

TOM: The idler arms attach the moving parts of the steering apparatus to the frame of the vehicle. When the idler arms wear out, the steering parts won't "stay put." It's then impossible to align the wheels because the steering components are "sloshing around." It's like trying to thread a needle while standing in the bathroom of a moving Greyhound bus--or something like that.

RAY: We've replaced enough idler arms on Astro Vans to conclude that these parts were probably under designed (ie. not heavy-duty enough). Many cars get 100,000 miles out of an idler arm, and we've replaced idler arms on Astros with far fewer miles than that.

TOM: If you've got 50,000 or 60,000 miles on the van, just bite the bullet, spend the $200, and have the arms replaced. But if you've got significantly less than that, I'd write to General Motors and suggest they make a sizable donation to IARF--the Idler Arm Relief Fund.

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