Idler arm - quick question

A quick question - just in the middle of changing my steering idler arm & when i got the old one off I found a thin shim between the arm & the rubber seal/spacer/ring. None of my manuals show a shim here, is there a well known reason to fit a shim (that I don't know about), or is it just another mysterious previous owner thing?
Thanks
Paul



A quick question - just in the middle of changing my steering idler arm & when i got the old one off I found a thin shim between the arm & the rubber seal/spacer/ring. None of my manuals show a shim here, is there a well known reason to fit a shim (that I don't know about), or is it just another mysterious previous owner thing?
Thanks
Paul
It's literally a thin shim placed under the seal between the idler arm & relay rod. It doesn't cup the seal (a thick rubber(?) ring), it just sits between it & the idler arm. I can't see any mention of it in any manuals so I left it out, but I'm wondering if there's some reason for fitting one?



