Genuine Audi 90 Shock Absorber

Audi 90 Shock Absorber Parts and Q&A

• Shock Absorber
  893-413-503-AA
  Q: How to properly compress a spring and check the efficiency of a shock absorber during strut maintenance on Audi 90?

  A:

  Attach spring compressor to the spring and attach the strut to a vice. Unscrew the slotted nut off the top of the piston rod and then screw the spring as far down as the upper spring retainer is, but leave it free; hold the piston rod in place with an Allen key. Take out the strut bearing and spring retainer and then remove the coil spring off the strut keeping the compressor in place and reference the top of the spring and make sure the colour code on the bottom faces outwards. Take off the rubber bump stop and boot, and make a note of the location of every single part, such as the extra cup and washer on heavy duty suspension. To test the efficiency of the shock absorber, move the piston rod through its full stroke, making sure that the resistance is smooth and consistent without evidence of seizing, and examine whether hydraulic shock absorbers have more than minor traces of fluid leakage, albeit normal traces of fluid. To refresh the shock absorber, remove the shock absorber used, and replace with a new one but in the case of hydraulic, open it and replace the old piston and rod and eliminate the hydraulic fluid. In order to replace or take away the shock absorber cartridge or piston rod, one needs to unscrew a top strut cap with Audi tool No 40-201 A or similar tool since this is very tight and cannot be done with a different tool. Take out the cartridge or piston in the strut and thoroughly clean the recess. Where necessary, take off the hub and bearing, the splash guard. Inspect the strut top mounting ball bearing to ensure that it is not overly worn by turning it manually, and replace it (where needed). Reassembly is the reverse of dismantling and care must be taken to ensure that the cap and the slotted nut are tightened up to the required torque and with models that have heavy duty suspension care should be taken to ensure that the convoluted rubber boot is attached to the cap. Fitting a new shock absorber, work the piston rod through all its travel in an upright position a number of times before replacing the strut.
• Shock Absorber
  893-513-031-AD
  Q: How to replace the shock absorbers and coil springs on Audi 90?

  A:

  Loosen the bootlid, remove the spare wheel (unless it is a necessity) then unscrew the trim at the front of the luggage area. Take off the plastic cap on the top of the shock absorber and chock the front wheels. Lift the back of the vehicle and hold it on axel stands that are set underneath the vehicle and then place the rear axle on a trolley jack. Unscrew the nut at the top of the shock absorber and unattach the cup and the upper mounting rubber and it is not recommended to take off both shock absorbers at the same time, as this would destroy the flexible hydraulic brake hoses. Reduce the rear axle until all of the tension is taken off of the coil spring and then unscrew and remove the shock absorber lower mounting bolt so that the shock absorber can be removed out of the car with the coil spring, damper ring, and mounting parts and the position of the mounting rubbers attached is noted. Take off coil spring, damper ring, lower spring seat, mounting, and bump stop rubbers. Clean all parts and examine wear and damage and, ensuring that both the shock absorber and coil spring are colour-coded, new parts should be the same colour as the parts removed. The operation of the shock absorber There are a number of times that the piston rod should be worked through the full stroke in a standing position before a new shock absorber is fitted. Installation is the opposite of the removal; with the spring lower seat, dust the upper rubber mounting rubbers with talcum powder then install them. Completely screw in the shock absorber lower fixing screw until the weight of the car is on the suspension, and replace all the self-locking nuts.