Volvo Coupes/Sedans/Wagons 1970-1989 Repair Guide

Flywheel and Ring Gear



The ring gear is contacted by the starter gear during engine start up. If any damage is found on the ring gear (broken or chipped teeth, cracks, etc.) the cause of the failure should be identified and repaired. The starter should be checked as a possible cause.

On vehicles with automatic transmission, the ring gear is an integral part of the flexplate and cannot be replaced. On vehicles with manual gearboxes, the ring gear on the flywheel can be removed and replaced. This replacement involves heating the ring to 450°F, and handling the heated ring. It is usually found to be easier to buy a complete flywheel and ring gear assembly than to attempt the replacement. If you possess the proper equipment for heating and handling the ring gear, the procedure is as follows:

  1. Remove the transmission.
  3. Remove the clutch plate and disc.
  5. Remove the bolts attaching the flywheel to the crankshaft flange. Remove the flywheel.
  7. Inspect the flywheel for cracks, and inspect the ring gear for burrs or worn teeth. Replace the flywheel or ring gear if any damage is apparent. Remove burrs with a mill file.

To install:
  1. To replace a ring gear use the following steps.
    1. Use a 10mm drill and drill a hole between two cogs (teeth) on the ring gear, being careful not to drill into the flywheel.
    3. Mount the flywheel in a vise protected by soft jaws and split the ring gear at the hole with a chisel.
    5. Heat the new ring gear to approximately 450°F. When handling the heated ring, wear heavy gloves and use tongs.
    7. Position the ring gear with the bevelled side facing the flywheel. <