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[Radar]

As above and had the wishbones changed and full geometry set. The steering feels much more responsive and the previous judder i used to get through the steering wheel has gone . Tony said the toe and camber was well out and made the necessary adjustments. However the car still pulls slightly to the left. (The wishbones were torqued up whilst on the ramp and Tony assured me there was no need to torque them up on the ground) .Is there something i have missed or can anyone give any pointers as to the cause?

[Abiton]

If it was on its wheels on the ramps, that's the same as being on the ground, no?

[Radar]

The wheels were definitely off at the time and it was lifted from the jacking points (i think)

[feeutfo]

The wheels were definitely off at the time and it was lifted from the jacking points (i think)

Well he's f*cked up then.... sorry, just has!

[feeutfo]

The reason for having the car loaded is;

The bush has a centre spacer set int the rubber with the metal outer. When the bolt is done up on the wishbones and hence the bush centre spacer the centre spacer is clamped by the subframe bracket due to the force applied by the bolt.

If the wheels are hanging then the centre spacer is clamped with the suspension topped out/fully extended, with the centre spacer clamped in that position, which means the when the car is driven "on the ground" the wishbone rises from the clamped position, this means that the bush is constantly twisted. The more the suspension compresses, like when its dropped off the jacks, the more it twists the rubber in the bush and it rips the rubber apart causing early failure.

If tightened wheels loaded then the bush centre spacer is set in the middle of its travel in a neutral unstressed position. Only when the suspension moves up or down of the ride hight position does the bush become stressed. As opposed to over stressed all the time if tightened wheels hanging.

In effect the bush is trying to hold the car up in the air as its set now, because the bush naturaly wants to return to its unstressed position, that being with the suspension fully extended (wheels hanging)

asap i would get under the car and undo the bolts, esp the front horizontal bolts, the rear vertical bolts dont matter due the plane the rear bush operates in.(a thought occurs at this point, explane later)
You'll probably hear the centre spacer ping round when the bolt is released. Then do the bolts up to 120nm plus angle tighten 30° then 15° wheels loaded. This is a pig to do without a ramp as wim have as the floor is in the way of the torque wrench.

hth

[hotel21]

When mine were done down there, a hydraulic ram was used to load the suspension arm at tightening.  Queried the matter but was told (nicely...) that it will be fine.

I am, however, starting to have some small doubts as to the handling, almost a year later.  Might just be less than great wishbones though.....   

[feeutfo]

When mine were done down there, a hydraulic ram was used to load the suspension arm at tightening.  Queried the matter but was told (nicely...) that it will be fine.

I am, however, starting to have some small doubts as to the handling, almost a year later.  Might just be less than great wishbones though.....   

Might be worth a bush examination and loosen and re tighten of the bolts...? what make where fitted do you know?

 But the fact they used a ram is better than nothing, and brings me to my earlier thought.

The rear bush is set reguardless of wishbone angle. If its to be unstressed at the ride hight position then that assumes that the desired ride hight position is equal to the position of the rear bush.

In other words would it be safe to fit the wishbone, insert the bolts with nothing else fitted to the wishbone and tighten the bolts at this point of the fitting process. The rear bush would then set the ride hight of the wishbone(assuming that position is correct?) reason i ask is tightening the wishbone bolts at this point would be a dam site easier. Then once bolts are tightened attach the strut/hub which would then force the wishbone down.

This assumes too much re suspension components condition and that the car will settle at the tightened wishbone angle/ride hight...but it would be a alot easier to tighten the bolts.

Hope that makes some sence?

[Turk]

The tightening of the bolts with the weight of the car on its wheels is purely to eliminate the risk of premature failure of the rubber bushes. Don't think it would affect the steering.
Sounds like WIM may need to adjust the camber a little more than their usual Mig settings.

[Kaycee]

In reply to that query which was so eloquently explained by chrisgixer i too after having front camber set at -1.10
by myself it still pulled to the left sllightly
so my settings are now Left Side -1.18 Right Side -1.10
the steering wheel is straight and the car drives as straight as an arrow i achieved these settings as i have previously said by measuring rim top and bottom and having a difference from top and bottom of 9 mm on Left side and 8mm on Drivers side maybe you might not aggree with this way but both my 2.5 CDX and my latest 3.2 elite ran with these Settings .after i had done this i went to the Local tyre fitters and asked them to check my settings that i suspected i had a Fault and would be changing something Steering Idler etc so they obliged and never charged as they did not change anything and the result was i got a read out for nothing

[jb]

Be aware that even with bang on geometry you can have tyres which have a bias fault causing pulling to one side or the other..........

[feeutfo]

Be aware that even with bang on geometry you can have tyres which have a bias fault causing pulling to one side or the other..........

very much so, and is exactly why i'm being so cautious before putting my 245 40 18s on, this is hard enough(and expensive enough) without without cock ups mentioned above.

I suppose we should give wim the benefit of the doubt though. There may well be something wim did that Radar didnt see that corrects matters. But on the evidence so far its just not correct procedure...

...also suprised others havent commented, maybe its just me?

[Radar]

Be aware that even with bang on geometry you can have tyres which have a bias fault causing pulling to one side or the other..........

very much so, and is exactly why i'm being so cautious before putting my 245 40 18s on, this is hard enough(and expensive enough) without without cock ups mentioned above.

I suppose we should give wim the benefit of the doubt though. There may well be something wim did that Radar didnt see that corrects matters. But on the evidence so far its just not correct procedure...

...also suprised others havent commented, maybe its just me?

Thanks for replies It was just the front wishbones replaced (lemforder). Tony did explain to me that the torquing up was the same as if it were done on the ground but i'm afraid he lost me in his explanation.

I did get the front passenger tyre changed the night before and despite me telling them what psi to inflate to i checked yesterday and it was 2psi lower than all the other tyres. I think the tyre bias point is a point to be noted and all in all it is much better than before with handling feeling more solid.

I wish i had more technical know how to explain why wim said it was ok but i don't. 

[wheels-inmotion]

We put a hydraulic ram under the wishbone and jack it up until it's horizontal so there's no preload in the bushings.

The camber positions are very safe and will not cause a pull, this is probably the tyres.

In addition we can adjust the castor angle if needed to stop a pull but in this case it wasn't necessary.

[Marks DTM Calib]

We put a hydraulic ram under the wishbone and jack it up until it's horizontal so there's no preload in the bushings.

The camber positions are very safe and will not cause a pull, this is probably the tyres.

In addition we can adjust the castor angle if needed to stop a pull but in this case it wasn't necessary.

Thanks for clearing that up Tony, I guess the jack goes under the ball joint point (beware, jacking under the wishbone bends them! )

[feeutfo]

ok good news, so to my earlier "thought" then...

does it amount to the same thing if....
the new wishbone is placed in position bolts inserted loose, the strut is pulled clear and the wishbone allowed to find its own position as dictated by the rear bush, being vertical/fitted flat it will presumably ammount to the same end result, that being a level wishbone. Then simply do the bolts up as is...? same fing no?

 Must say i think i would prefer the car off the jack then the bolts tightened at the true ride hight, but doing so on a drive way is such an almighty pita, would this method surfice?

seems easier to me?