jmmillerfzr

Went for an alignment today and was told the bold holding the front upper arm has a D snapped head and is in backwards? That the direction adjust the camber? Does anyone with a repair manual have any insight?

twentysevenlitres

Having just replaced my upper control arms last weekend I know the bolt he's referring to quite well!

It's nothing to do with camber adjustment, it's the bolt which holds the upper front control arm in position (if you weren't aware your car has 4 independent control arms on each side at the front - Audi's Quadlink suspension design).

As your aligner said, the front upper control arm is bolted to the upper strut mount using a bolt with a D-shaped head. The straight edge of the 'D' locks into a straight-edged tab on the bottom of the upper strut mount underneath the front control arm inner bushing. The bolt is mounted vertically (D-head on the bottom) with a nyloc nut on the top accessible from under the bonnet/hood.
When mounting the bolt to the upper strut housing (done with the strut off the car), a circlip is used which should locate the head to stop it spinning. there is also a spacer above the circlip which should positively locate the head by pushing the circlip down when the strut is put back into the car and the other mounting nuts are tightened.
If the head has spun, it was either not located properly before tightening the nut down, or the circlip or spacer weren't used properly, or it was just bad luck!
See pic below - Showing left hand side upper suspension. Offending bolt is number 12 on the diagram, Circlip is number 17, front upper control arm is number 10, and the spacer is number 2 (which Bentley shows as mounting on the top under the nut and washer - maybe mine was wrong?).



Anyway, it should be relatively easy to correct yourself should you wish.

• Take the wheel off on the appropriate side (I hope your aligner told you which side!). The D-head is quite accessible with the wheel out of the way.
• locate the most forward nut on the strut tower (out of 5) on the engine side of the firewall under the bonnet/hood.
• It will most likely be under a plastic cover - either the large surround for the washer bottle and airbox on the right hand side, or the smaller plastic strut cover in behind the radiator expansion tank.
• Loosen the nut off (you won't need to take it off, just loosen it) - 16mm or 17mm socket required.
• Get a shifter (adjustable spanner/wrench - what do you guys call them, channel locks or something?) and turn the D-head until the flat edge locks in with the tab on the strut mount (if you can't get the shifter up there, find an appropriate sized regular open ended spanner/wrench - 16mm or 17mm I would think).
• Hold D-head in position with one hand, whilst tightening the nut back down with the other to ensure it's locked in position.
• Torque to 100Nm (74 ft lbs).

No need to worry about torquing the bushing at ride height in this instance, as it's a vertical mounted bolt.