Steering Wheel - Shimmy When Braking
90audi07Subject: Steering Wheel Shimmy During Braking
Model(s): 5000S Quattro/5000T/5000CS Quattro 1986-1988
200 Turbo/200 Turbo Quattro from 1989 m.y.
Group: 46
Number: 90-01
Date: November 30, 1990
Follow the procedure below to eliminate recurring problems with steering wheel shimmy during braking.
Note
The wheels and tires on the vehicle must be in good condition before proceeding with the following operations.
^ remove front wheels
^ disconnect front brake pad sensors (arrow)
^ remove front brake pads
^ remove both front brake calipers but do not disconnect hydraulic lines
CAUTION
Use wire to suspend brake calipers from body of vehicle. Do not let calipers hang from hydraulic lines.
Vehicles with less than 40,000 miles
^ carefully inspect inner and outer control arm bushings for cracking, spliffing and deterioration (arrows)
Note
Bushings are difficult to inspect in the installed position. Use a flex mirror and a bend-a-light to inspect the bushings as thoroughly as possible.
^ replace worn or damaged bushings as necessary
Vehicles with more than 40,000 miles
^ replace both front inner and outer front control arm bushings (arrows)
Note
Refer to the repair manual microfiche for bushing replacement procedures.
Front brake rotors, truing
^ true front brake rotors with an on-the-car brake lathe, e.g. Kwik-Way Kwik-Lathe(R)
Note
If an on-the-car brake lathe is not available, replace both front brake rotors.
See page 4 for instructions regarding installation of new rotors.
CAUTION
Do not true the front brake rotors off the car during this procedure.
Note
The minimum thickness specification for brake rotors is located on the outside of the part (arrow)
^ if necessary, install new brake rotors, Part No. 447 615 301 B
CAUTION
Part numbers are for reference only. Always check with your Parts Department for latest Information.
^ index rotor to hub using center punch
Note
Follow the manufacturer's instructions for correct setup and operating procedures.
After rotors are trued proceed to caliper and wheel installation, page 5
When new brake rotors are required:
^ thoroughly clean contact surfaces of brake rotor and hub
^ install using all lug bolts with suitable spacers (e.g. axle nuts)
^ tighten lug bolts diagonally in stages to 40 N-m (29 ft.lb.)
^ attach dial indicator to measure brake rotor runout
^ locate dial indicator approximately 10 mm (3/8 in.) from outer edge of rotor
^ rotate brake rotor and record highest runout
^ remove brake rotor and remount after rotating rotor to next lug bolt hole
^ recheck brake rotor runout
^ continue remounting rotor checking runout at each lug bolt position
^ maximum rotor runout: 0.06 mm (0.002 in.)
^ mount rotor in position where lowest runout was achieved
^ mark hub and rotor with center punch as mounted in lowest runout position
^ repeat runout checking procedure on opposite front rotor
Brake calipers/wheels, installing
^ install front brake calipers
^ Install new Ferodo 3411 brake pads, Part No. 447 698 151 F
CAUTION
Part numbers are for reference only. Always chock with your Parts Department for latest information.
^ install wheels and torque lug bolts to 110 N-m (81 ft.lb.)
Labor operation
46 50 51 1 Inspect control arm bushings and replace front rotors: 145 T.U.
46 50 51 2 Replace front control arm bushings and rotors: 185 T.U.
46 50 51 3 Inspect control arm bushings and true front rotors: 225 T.U.
46 50 51 4 Replace control arm bushings and true front rotors: 265 T.U.