All rear suspension link bolts must be tightened with the rear axle horizontal, i.e. the rear axle must not be hanging down when the suspension link bolts are tightened.

The bushings in the supension links act as torsional springs and they have to be unstressed at ride height i.e. when the vehicle is set down on its wheels.

If the suspension is at its lowermost position (also called full droop position) (for example when the vehicle is lifted off the ground and supported by the four jack points on the chassis and the wheels are hanging down unsupported) when you tighten the bolts on the links, then that becomes its neutral position and when you let the vehicle down on its wheels, the busings get wound up and you have basically loaded the torsion springs. Now the torsion springs (i.e. busings) will try to react the load and go back to their neutral position which would be the full droop condition thereby jacking the car up on the rear.

Also, if the rear suspension link bolts were tightened with the supension in full droop, then all the suspension link bushings will prematurely fail since they are loaded all the time.

If you do a search there are a few articles that discuss how to support the suspension to get the rear axle to be horizontal befor tightening the bolts.

Good luck and keep us posted.

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1986 300E (3/2002) Rear ended and totaled (10/2009)
2000 Xterra (5/2000)
1992 400E (11/2009) -Sold
1986 300E (12/2009) - Sold
2004 E500 Wagon (6/2013) - Sold