70 series control arm loading question

[erikv11]

Just reading this thread. There are so many suggestions for jacking under the control arm, but hopefully people realize they are all exactly the same, noone is better (or any different!) from another. Jacking until the arm is near to level, jacking until you measure a certain height, jacking just until the car starts to raise ... they all do the same thing. Just do what for you is safe and easy to remember.

I have also pre-loaded them by putting on the wheels and dropping the car onto ramps, it works great but I find it to be a hassle in my narrow garage space. Jobs like preloading are exactly why I hang on to that otherwise useless little (2 ton) lightweight hydraulic jack!

[scot850]

Just thought I would add to the info and not correct Lee, but clarify. There is a pre-load for the rear suspension on AWD cars. Volvo has a special tool that jacks under the lower control arms and lifts the car by rollers running out on the control arms. Like the picture shown here, you measure the distance from the center of the axle at the hub, to the wheel arch:

The rear suspension is in the normal position when
the distance from the fender edge (1) to the center of
the wheel (2) is 381 mm (15”).

If you read my blog on the subject, you find there is no mention of how to set the upper control arm bushes. You cannot do this without the weight of the car on the suspension, but with the weight on the suspension, you must have the fuel tank removed to access the nut on the front bolt of the upper control arm. Volvo would not release a how to, so eventually, I measured the free height of the lowest point at the center on the top side of the upper control arm to the top edge of the sub-frame on both sides. One was 125mm and the other 135mm. I averaged and set it at 130mm.

I then used the same method as suggested for the lower control arm and other suspension bolts and raised the lower control arm at a point as close to the hub under the lower control arm until the measurement was achieved. In this case you can lift the control arm higher than the required position!

The dealer then confirmed all was good and torqued correctly when I took the car in for 4 wheel alignment.

Neil.