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Old 01-17-2021, 01:33 PM
oldskewel oldskewel is offline
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Quote:
Originally Posted by Clavurion View Post
Remember that you should disconnect stabiliser link when jacking the hub. Otherwise part of the weight is distributed to other axle via stabiliser and the vehicle rises off the stand before the hub is in neutral position.
It's true that leaving the stabilizer links connected will mean that the link is pulling the side you're working on down, assuming that the other side is in the air as well, so the stabilizer bar is torqued.

But what you are actually aiming for here is not to match the grounded force by each component, but rather the resulting on-the-ground bushing geometry. So measuring hub center to fender lip distance is what you acutally want to be matched, regardless of what forces and torques put it in that position.

If the car is off the ground and the suspension is jacked up so that distance matches, then the suspension bushings will be in the same geometry as if they were on the ground, and you can torque them safely.

So rather than take the extra step of disconnecting the sway bar link, I jack a little further out to compensate for leaving that extra force on the suspension. And BTW, it's not just final torquing - the bushing bolts should be loose enough that they can freely find their stress-free rest positions.

I actually just replaced my guide links and did an alignment, so I went ahead and measured things so I could provide solid info.

With the car on the ground, I measured 18-1/4" from hub center to the underside of the fender lip. When jacking the suspension prior to final torquing, I had the jack contact point about one inch inward of the outer edge of the brake rotor top hat (so this is further outboard vs. where the effective force center from an installed wheel on the ground would be, so the same force would give more torque, giving a little extra spring compression and suspension movement). I jacked until the car just started to lift off the jack stand.

I measured the hub-fender distance at 18-1/8", so actually a little more compressed, but within measurement error, so I'll call it the same. And not needing to touch the stabilizer link was nice.

Simplified summary: the stabilizer link is pulling upward, but due to choosing a further-outboard jacking point, the lifting torque is greater, and they offset if you do it right.


- also, well done @SBBimmer. And I'll say it was a good move to not try to compress the springs. I think that step has caused many people a lot of problems since it is very difficult to find spring compressors that will fit in the tight space there. I am lucky (or not) to have some really old compressors from back when cars weighed half what my X5 weighs. Those barely fit, and I use them only to hold the spring in a compressed state, not to compress it further. Very tough to find new ones that fit, as far as I know.
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2001 X5 3.0i, 203k miles, AT, owned since 2014

Last edited by oldskewel; 01-17-2021 at 01:39 PM.
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