If you are talking about the little plastic cap, it is a seal for the dipstick tube in the transmission that keeps out dirt until the vehicle is ready on the production line to have the dipstick tube installed. No harm there.
If you mean literally small pieces, this would be the speedometer gear. This may be the cause of the speedo fluctuation you speak of as well. The contamination from the busted plastic gear can get imbedded in the clutches and bands (if any). Doing so will cause the transmission to have more damage creating a snowball effect doing more damage to itself overtime.
Saturday, December 20th, 2008 AT 12:41 PM