Caution for Multi-Link and Double Wishbone Suspensions

In multi-link and double wishbone suspensions, if you tighten the upper arm bolts in an elevated vehicle, the ride height will not drop. This applies when the suspension arms attach to the vehicle body via rubber bushes, which is in most cases. You need to fully tighten the bolts when the car is back on the ground.

The relatively complicated multilink and double wishbone systems are becoming more common, because of their active and precise control of alignment changes during driving. When installing new shock absorbers or low down springs, you usually jack or lift up the car and temporarily detach the upper arm (Photo 1) from the vehicle body. Now when reattaching it at the end, if you tighten its bolt (Photo 2) while still in the air, its rubber bush will twist. The strain blocks the ride height drop, back at ground level. In the worst case, the bushes can become damaged.

The solution is to only loosely tighten the upper arm bolt with the vehicle lifted up, and fully tighten when it is down on the ground again (Photo 3). This prevents unnecessary strain on the rubber bush, so that the ride height will be as you set it up. We recommend also taking a test drive and checking your readings, since there may be another similar problem, such as failure of ride height drop unless the handbrake is released at ground level (Honda Fit GD2/4).