Chrysler Full-Size Vans 1967-1988 Repair Guide

Flywheel/Flex Plate and Ring Gear


Flex plate is the term for a flywheel mated with an automatic transmission.


See Figures 1, 2 and 3

Click image to see an enlarged view

Fig. Fig. 1: If necessary, lock the flywheel in place and remove the retaining bolts ...

Click image to see an enlarged view

Fig. Fig. 2: ... then remove the flywheel from the crankshaft in order replace it or have it machined

Click image to see an enlarged view

Fig. Fig. 3: Upon installation, it is usually a good idea to apply a thread-locking compound to the flywheel bolts

The ring gear is replaceable only on engines mated with a manual transmission. Engines with automatic transmissions have ring gears which are welded to the flex plate.

  1. Remove the transmission and transfer case.
  3. Remove the clutch, if equipped, or torque converter from the flywheel. The flywheel bolts should be loosened a little at a time in a cross pattern to avoid warping the flywheel. On cars with manual transmissions, replace the pilot bearing in the end of the crankshaft if removing the flywheel.
  5. The flywheel should be checked for cracks and glazing. It can be resurfaced by a machine shop.
  7. If the ring gear is to be replaced, drill a hole in the gear between two teeth, being careful not to contact the flywheel surface. Using a cold chisel at this point, crack the ring gear and remove it.
  9. Polish the inner surface of the new ring gear and heat it in an oven to about 600°F (316° C). Quickly place the ring gear on the flywheel and tap it into place, making sure that it is fully seated.

Never heat the ring gear past 800°F (426° C), or the tempering will be destroyed.

  1. Position the flywheel on the end of the crankshaft. Torque the bolts a little at a time, in a cross pattern, to the torque figure shown in the Torque Specifications Chart.
  3. Install the clutch or torque converter.
  5. Install the transmission and transfer case.