Rear Lifted after Upper and Lower Control Arm Bushings

Zolll · Post by **Zolll** » 31 Aug 2020, 08:22

Hi There, I've recently replaced the rear Upper and Lower control arm bushings with polyurethane ones on my 2004 XC70. The upper arm bushings were shot so I took the opportunity to upgrade the bottom arms bushing while at it. An online search on changing these bushings had zero results; seems like no one has ever changed the rear UCA & LCA bushings - I can't blame anyone, it was a 20 hour job! Anywho, after all was done, the rear is now sitting approximately 1.5-2" higher than before, to a point where I'm competing with Tacomas. My mechanic said that he was able to properly align the rear despite that. A week of driving did not show sign of 'settling'. Anyone knows what could've caused this, spring seats? A worn bushing would only have 1/4" of play at max and ride height appeared normal before. The ride is much tighter now but it feels like the rear end is laterally jumpy on bumps!

Thanks!

Post by **RickHaleParker** » 01 Sep 2020, 01:29

Lever and and fulcrum ... mechanical advantage. A little bit of movement on one end of a lever results in a much greater movement on the other end of the lever.

The new bushings do not compress as much and hold the control arm closer to perpendicular then the old ones did.
In short: The new stiffer bushings changed the angle which the control arms ride.

Hold a pen by the end, wiggle it a little and watch how much more the other end moves.

This is why it is much easier to touch something with a yard stick then it is to touch it with a 10 ft pole.

RicardoV · Post by **RicardoV** » 13 May 2023, 14:05

Zolll wrote: 31 Aug 2020, 08:22 Hi There, I've recently replaced the rear Upper and Lower control arm bushings with polyurethane ones on my 2004 XC70. The upper arm bushings were shot so I took the opportunity to upgrade the bottom arms bushing while at it. An online search on changing these bushings had zero results; seems like no one has ever changed the rear UCA & LCA bushings - I can't blame anyone, it was a 20 hour job! Anywho, after all was done, the rear is now sitting approximately 1.5-2" higher than before, to a point where I'm competing with Tacomas. My mechanic said that he was able to properly align the rear despite that. A week of driving did not show sign of 'settling'. Anyone knows what could've caused this, spring seats? A worn bushing would only have 1/4" of play at max and ride height appeared normal before. The ride is much tighter now but it feels like the rear end is laterally jumpy on bumps!

Thanks!

Post by **scot850** » 13 May 2023, 16:42

Did you tighten all the control arm bolts while the car was on the ground with weight on them? If not, then maybe you want to loosen them again and re-tighten with the weight on the suspension.

Neil.