Idler Arm Failure

My 73 Duster is on it's third replacement idler arm in maybe 30,000 miles. The last one that failed was a moog problem solver which looked pretty robust but had gone completely loose at the centerlink pivot. loose enough that the linkage was hitting the header where it did not before. Current one installed over the week end is a TRW which surprisingly uses the same forging as the moog but does not have problem solver stamped on the cover plate. It too looks up to the task.

The car has headers and the idler comes in close contact but never touches them although I am sure the part gets hotter now than it did with manifolds on it.

Assuming the quality is there because I never had problems with moog or trw parts in the past on any of my other cars (chevys) I am thinking it's possibly a heat related and lubricant problem.

Until recently I never gave much thought to the type of chassis lube I used. Most of the time it was a lithium based multi purpose lubricant. After researching a bit I found that some lithium based lube has molybdenum added as an extreme pressure additive to prevent scuffing, galling and wear. I also noticed different grades and brands have higher operating temperatures where the oil won't separate from the lithium soap it is mixed with. All the time I spent on researching the best motor oil it never occurred to me that not all greases are created equal.

The idler seems to fail more often than any other steering component which means it needs a high quality lubricant to protect it under the high heat and pressure it sees, especially with headers. So far I have found the lithium with moly added is available even at wally world. There are some synthetic lubricants too but may not mix with the lithium based stuff already in my parts. I suspect the 2525035 multi-mileage lubricant called out in my owners manual was moly-lithium grease. It only said to lube every 36 months or 36,000 miles. I lube every 3,000 when I change the oil.


Thoughts?