w108,107 Parts Hoarder
Date registered: Jun 2010
Vehicle: 4Keep:450slc5.0cab 280sl5sp 280se4.5 500seAMG 2sell:500sl92 380se83 300se86 350sl4sp 75slc MorInSig
Location: Philadelphia Area
Mentioned: 29 Post(s)
Quoted: 1672 Post(s)
What happens when you jack up these rear axles is the wheels come down really far and swing IN. So for sake of conversation, let's say there's 4 feet between the two tires when the axle is straight. Then when you jack it up in the air, the bottom side of the tires is only maybe 3 feet apart. Then you drop the car back down, and the tires hit the pavement, and the rubber doesn't slide out as the tires force outward pressure on the pavement. The friction holds the rear end up in the air. You need to roll the car forward or backward to allow the sideways friction to be eliminated.
I learned this when I ruined some freshly laid blacktop on a hot day at my mechanics lot. The car ultimately slid down by pushing a large chunk of black top outward on one side, creating a huge divot in my mechanic's lot. My mechanic LOVES me! (Sarcasm.)