1993 850 sedan

so I'm gonna do it. Replace timing & serpentine belts, pulleys, rollers, damper, water pump - I don't want to open this engine again for a while. Bought all the parts, got some tools on loan from autozone (great program)

I'm ready...except for few questions.

Posts on this and other forums concerning timing belt replacement mentioned when replacing the dampener/tensioner part to replace the "plastic disc or clip" that snaps on (i believe) to the top of the dampener. Then again several posts concerning timing balt replacement do not mention this disc.

I called fcp groton for advice as I had purchased the belt there. The rep on the phone sounded knowledgeable and stated he'd never heard of or sold such a plastic part. Autozone and their supplier Goodyear didn't know about it either.

So I'm asking the Collective Wisdom of this forum for an opinion. Based upon actual experience, is this plastic piece that snaps onto the dampener arm important or not? Not having done a belt on an 850 I don't know whether the dampener arm beats against the belt and the disc provides wear and abrasion resistance preventing breakage. Or is it unnecessary? Or should I use the one from the old part if it's there?

This is one of those times when I could use help from someone' who has "been there."


Thanks

Paul