For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
1 | Check for loose engine mounts. Refer to Transmission Front Mount Replacement or Transmission Rear Mount Replacement . Are any of the engine mounts loose? | Go to Step 2 | Go to Step 3
2 | Tighten any loose engine mount. Refer to Transmission Front Mount Replacement or Transmission Rear Mount Replacement . Has the noise disappeared? | System OK | Go to Step 3
3 | Check for a worn or damaged inboard drive axle joint. Is the joint worn or damaged? | Go to Step 4 | Go to Step 5
4 | Repair or replace inboard drive axle joint. Refer to Wheel Drive Shaft Inner Joint and Boot Replacement or Wheel Drive Shaft Outer Joint and Boot Replacement in Wheel Drive Shafts. Has the noise disappeared? | System OK | Go to Step 5
5 | Check for a worn differential side case pinion shaft. Refer to Differential Case Disassemble in the M86/M94 Section of the Transmission Unit Repair Manual. Is the shaft worn? | Go to Step 6 | Go to Step 7
6 | Repair or replace the differential side case pinion shaft. Refer to Differential Case Disassemble in the M86/M94 Section of the Transmission Unit Repair Manual. Has the noise disappeared? | System OK | Go to Step 7
7 | Check for a worn or damaged side gear hub counterbore. Refer to Differential Case Disassemble in the M86/M94 Section of the Transmission Unit Repair Manual. Is the counterbore worn or damaged? | Go to Step 8 | Go to Clutch and Differential Housing Cleaning and Inspection in the M86/M94 Section of the Transmission Unit Repair Manual
8 | Repair or replace the counterbore. Refer to the M86/M94 Section of the Transmission Unit Repair Manual. Has the noise disappeared? | System OK | Go to Bearing Noise