The yellow bumpers are designed to be part of the suspension springs. They should be close to touching, if not touching, the lower control arm. They are a foamed polyurethane, softer than the rubber ones you used to see on vehicles. They are also tunable, in that they can be soft on initial contact and get harder as the suspension gets close to full compression.
Trust me, they are supposed to be that way. Go through a big dip and you notice (or don't notice) the impact into the bump stops. Try taking them out and do the same thing, after you get your chipped teeth fixed, you'll realize they work well.
2002 Chevy 2500HD LT, 4x4, CC, SB, 8.1L, Allison, Summit White w/Grey Leather<br />- Rancho 4\" Suspension Lift, RS9000 shocks, steering stabilizer, and skid plate<br />- 285/75R16 BFG AT KOs on 16x8 Weld Sidewinder wheels<br />- Snugtop Xtra Vision shell, BedRug, Go Rhino side steps