Help Please Replacing lower control arms - torquing after driving up on a ramp

[fast-ferret]

TL;DR - can I replace the control arms, tighten (but not torque) the bushings, reattached the wheels, drop the car, drive it on a set of ramps, then torque them up whilst on the ramp?

Hey all, I've got to do some lower control arms. Admittedly this is on a Q5 but I'm posting here as I know several decent-minded folk are here and besides, the arms are the same on the Q5 so no difference really!

I have previously done the lower arms on my S4 but I wasn't happy with how I did it. I have a quickjack so I lifted it up on that and swapped the arm (on the Q5 I'm doing the guide link by the way), then I used a bottle jack to lift up the knuckle to ride height and torqued the arms.

I didn't like this because it lifted the car quite far off the quickjack and it just didn't feel a good way of doing things.

I've read two opinions:

1. You should do as I did above and jack the knuckle so the suspension is totally at ride height
2. You only need to jack the knuckle such that it just starts lifting away (in my case from the quickjack)

I don't really feel comfortable with number 2 to be honest so I'd much prefer to do number 1. My thought was to jack up on the quickjack, swap the arm but not torque the bushing, then reattach the wheels, lower the car on to wooden blocks or cribs and torque the arms up. Problem there is the quickjack only lifts the car enough such that there is about 8cm or so under the wheels which i don't think gives me very good room to be able to torque the arms up, so i thought ok - i'll just lower the car to the ground and then drive up on to a set of ramps. Problem is, I'm worried about moving the car without the bushings torqued.

Is this a bad idea? Anyone else got any better ideas?

 

[rum4mo]

I have not done this work -yet, but I'd probably carry out the final tightening up with the car on its wheels and after running it back and forwards to settle the suspension, and then up onto a set of 4 solid wooden ramps to let me get under it while it was its wheels, to torque up the bolts.

Now, after saying that, I can't see any reason to worry about carrying out the final torqueing of these bolts by just jacking that wheel hub up to get the height/gap correct as after all, what you are trying to do, as well as torqueing up all these bolts, is to do that when the links etc are in their "normal" position and so to avoid early death of the bonded bushes.

Edit:- I am willing to listen to other more experienced fixers though seeing as this is a job I have not yet carried out on my 2010 S4.

 

[fast-ferret]

I'm more wondering if it's ok to drive the car up ramps without having the arms torqued at the time. I can't see why not, but then again I'm not a mechanic! I think I will only use ramps on the front.

 

[rum4mo]

I'm more wondering if it's ok to drive the car up ramps without having the arms torqued at the time. I can't see why not, but then again I'm not a mechanic! I think I will only use ramps on the front.

What sort of distance are you planning to drive the car to get to ramps, I'd expect if you nip up all the bolts through bonded bushes then back the nuts off until the bolt is not gripping the bonded bushes tight, that would be safe enough and so they would stay on the car and the inner steel bonded sleeves would only rotate slightly as the suspension moved up and down - I'd only do that if I was from that point only driving a couple of miles to a ramp for torqueing them up.

 

[fast-ferret]

Oh I'm literally driving on to them in my garage. I presume there is no issue doing this but wanted to be sure I mean actual ramps as well, e.g. these:

 

[rum4mo]

Oh I'm literally driving on to them in my garage. I presume there is no issue doing this but wanted to be sure I mean actual ramps as well, e.g. these

It would really only work if you raised the car up onto 4 equal height ramps as only lifting the front up will depress the front suspension more than normal level would.