Just some comments from me as I've finally got round to replacing all the arms on the front end of my S4, initially I felt the need to change the arms because on passing speed bumps etc there was a "firmer" noise on compression coming from the RHS of the car, then I got a bee in my bonnet about replacing the M12 front lower front arms for M14, then last year I had an ABS sensor fail and when checking the face of the new ABS front wheel sensor after 100 miles, there were scuff marks on it, which meant that there was rusting on the reluctor magnets which on older cars are left exposed - newer versions of wheel bearings have them potted for protection, so I knew that this new ABS wheel sensor would have a limited life, so more reason to get stuck in and sort things out, then I started feeling a slight bit of "wobble feedback" on the brake pedal, so in for penny changed to in for a pound or lots more!
Removing the lower pinch bolts - eventually the RHS came out after lots of PB blaster soaking including building bunds around all 4 pinch bolt locations using Blu Tac and leaving for many days, induction heater a few times, followed by air hammer a few times and even some heat from a gas torch. The top pinch bolts are not for moving even after all that "pretreatments" followed by air hammer and the usual removal tool. The LHS lower pinch bolt released - but didn't unscrew, ie sheared at low applied torque! Attempts to work on its remains - sheared exactly at the end of the threaded section by drilling pilot hole was limited due to access while everything was built up on the car, so that ended badly with me drilling a pilot hole on the sheared bolt head and using that and a very long drill bit to attack things from the other end, unfortunately this lead to that drill wandering off and now I ended up in big trouble as when this hole was opened up enough to get a "good" sized "easy out" into it, the hole was touching the aluminium upright.
Now, I must say, I did expect the drilling of holes in this seized bolt would have encouraged it to unscrew - sadly I was wrong there! If I had seen this coming I would have removed the complete upright and arms from the car and in doing that I'd have been able to work on this bolt in a more controlled manner - but I didn't!
Anyway, with this painfully slow progress and the thought of needing to extract the wheel bearing from the upright on the other side, I just thought, "F' ck it" and relieved my wallet of lots of cash and ordered in 2 new Cobapress uprights from Audi - one of which, the already damaged one, was on back order from Audi's supplier"!
Doing that meant buying in a second SKF hub/bearing, more money, but meant that I could build up everything ready just to sort of swop over.
Tools that I now consider essential for the home car sorter working with the car only up on jack stands, are, torque wrench adaptors - these let you get onto the front lower rear arm nut and torque it up accurately prior to adding on the extra angle tightening using a flat hex ring and one of these "spanner extenders". Same really when torquing up the front upper arms, I'd bought a set of these torque wrench adaptors a few years ago and finally they have come into use!
Having a 3/4" long breaker bar and sockets, both for the drive shaft bolt and for the lower brace bolts helps a lot as does having someone to hold the brakes on while you remove and fit these drive shaft bolts, also handy to have someone to hold the steering wheel to each side while you remove the calliper carrier bolts and refit them.
Being aware that on cars with hydraulic steering that there is a flexible pipe mounting nut that needs removing from the lower brace is really useful!
Having a BiHex socket to use on the TRE nut is useful, I didn't originally have one in my socket set - I do now.
After completing that job, I've finally given in and bought in a set of deep sockets with a slot in the side, really so that I am in a position to actually torque the nut on the top of dampers - rather than doing what I've always done up to now which is "that is tight enough" from experience and feel! (I took the strut apart to replace the top mounting just in case it was contributing to any of the noises under compression)
Removing the lower pinch bolts - eventually the RHS came out after lots of PB blaster soaking including building bunds around all 4 pinch bolt locations using Blu Tac and leaving for many days, induction heater a few times, followed by air hammer a few times and even some heat from a gas torch. The top pinch bolts are not for moving even after all that "pretreatments" followed by air hammer and the usual removal tool. The LHS lower pinch bolt released - but didn't unscrew, ie sheared at low applied torque! Attempts to work on its remains - sheared exactly at the end of the threaded section by drilling pilot hole was limited due to access while everything was built up on the car, so that ended badly with me drilling a pilot hole on the sheared bolt head and using that and a very long drill bit to attack things from the other end, unfortunately this lead to that drill wandering off and now I ended up in big trouble as when this hole was opened up enough to get a "good" sized "easy out" into it, the hole was touching the aluminium upright.
Now, I must say, I did expect the drilling of holes in this seized bolt would have encouraged it to unscrew - sadly I was wrong there! If I had seen this coming I would have removed the complete upright and arms from the car and in doing that I'd have been able to work on this bolt in a more controlled manner - but I didn't!
Anyway, with this painfully slow progress and the thought of needing to extract the wheel bearing from the upright on the other side, I just thought, "F' ck it" and relieved my wallet of lots of cash and ordered in 2 new Cobapress uprights from Audi - one of which, the already damaged one, was on back order from Audi's supplier"!
Doing that meant buying in a second SKF hub/bearing, more money, but meant that I could build up everything ready just to sort of swop over.
Tools that I now consider essential for the home car sorter working with the car only up on jack stands, are, torque wrench adaptors - these let you get onto the front lower rear arm nut and torque it up accurately prior to adding on the extra angle tightening using a flat hex ring and one of these "spanner extenders". Same really when torquing up the front upper arms, I'd bought a set of these torque wrench adaptors a few years ago and finally they have come into use!
Having a 3/4" long breaker bar and sockets, both for the drive shaft bolt and for the lower brace bolts helps a lot as does having someone to hold the brakes on while you remove and fit these drive shaft bolts, also handy to have someone to hold the steering wheel to each side while you remove the calliper carrier bolts and refit them.
Being aware that on cars with hydraulic steering that there is a flexible pipe mounting nut that needs removing from the lower brace is really useful!
Having a BiHex socket to use on the TRE nut is useful, I didn't originally have one in my socket set - I do now.
After completing that job, I've finally given in and bought in a set of deep sockets with a slot in the side, really so that I am in a position to actually torque the nut on the top of dampers - rather than doing what I've always done up to now which is "that is tight enough" from experience and feel! (I took the strut apart to replace the top mounting just in case it was contributing to any of the noises under compression)
