Chrysler Full-Size Trucks 1967-1988 Repair Guide

Flywheel and Ring Gear


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


See Figure 1

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 trucks 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 drift or a cold chisel, tap downward on the ring gear near welded areas to break any weld material. Tap around the ring gear until it comes off the torque converter.

Click image to see an enlarged view

Fig. Fig. 1: Remove the ring gear by tapping downwards using a drift or chisel

To install:
  1. Polish the inner surface of the new ring gear and heat it in an oven to about 200°F (93°C), allow to stay there for 15 to 20 minutes. 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. Reweld the ring gear to the torque converter front cover, being careful to place, as near as possible, the same amount of weld in the exact same places that were used in the original weld.
  3. 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.
  5. Install the clutch or torque converter.
  7. Install the transmission and transfer case.