MBE 900 – Section 1.11 Flywheel Ring Gear

Section 1.11
Flywheel Ring Gear

Replace the flywheel ring gear; do not repair it.‪

Section 1.11.1
Flywheel Ring Gear Removal

Remove the flywheel ring gear as follows:‪

1. Remove the flywheel from the crankshaft flange. Refer to "1.10.1 Flywheel Removal" .

   BURNS ‪
   To avoid injury from burning, use lifting tools and heat-resistant gloves when handling heated components.‪

2. Heat the ring gear on the flywheel with a torch and press the gear off. See Figure "Heating the Ring Gear" .
   

   Figure 1. Heating the Ring Gear

Section 1.11.2
New Flywheel Ring Gear Installation

Install the new flywheel ring gear as follows:‪

1. Check the amount of overhang between the flywheel mounting shoulder and the ring gear. See Figure "Flywheel/Ring Gear Overhang Measurements" . The overhang must be within the permissible values listed in Table "Ring Gear Specifications" .
   

   1. Ring Gear‪

   2. Flywheel‪

   Figure 2. Flywheel/Ring Gear Overhang Measurements

   1. Measure the flywheel shoulder diameter (see Figure "Flywheel/Ring Gear Overhang Measurements" , B).
   2. Measure the inner diameter of the new ring gear (see Figure "Flywheel/Ring Gear Overhang Measurements" , A).
   3. Determine the amount of overhang by subtracting the ring gear inner diameter (see Figure "Flywheel/Ring Gear Overhang Measurements" , A) from the flywheel shoulder diameter (see Figure "Flywheel/Ring Gear Overhang Measurements" , B).
   4. Make sure that the amount of overhang lies between 0.295 and 0.575 mm (0.0116 and 0.0226 in.).

   BURNS ‪
   To avoid injury from burning, use lifting tools and heat-resistant gloves when handling heated components.‪

2. Heat the new ring gear to 250 to 280°C (482 to 536°F).

   Note: When sufficiently heated, the metal should be a bright yellow annealing color.

3. Press the heated ring gear completely onto the mounting shoulder of the flywheel.
4. Tap the holes for the clutch mounting bolts. See Figure "Flywheel Cross Section" . The specifications are listed in Table "Ring Gear Specifications" .
   

   1. Ring Gear‪

   2. Flywheel‪

   Figure 3. Flywheel Cross Section

   Description‪	Four- and Six-Cylinder Engines‪
   Flywheel Shoulder Diameter (for ring gear mounting - see Ref. A) ‪	392.435–392.575 mm (15.4502–15.4557 in.)‪
   Hole for Mounting Clutch Pressure Plate (see , Ref B)‪	3/8–16 UNC‪
   Thread Depth (see , Ref C)‪	24 mm (15/16 in.) minimum‪
   Ring Gear Inner Diameter‪	392.000–392.140 mm (15.4331–15.4386 in)‪
   Ring Gear/Flywheel Overhang‪	0.295–0.575 mm (0.0116–0.0226 in.)‪
   Ring Gear/Flywheel Permissible Radial Runout‪	0.5 mm (0.02 in)‪
   Ring Gear Width‪	15.6–16.0 mm (0.614–0.630 in.)‪
   Ring Gear Fitting Temperature‪	250–280°C (482–536°F)‪

   Table 5. Ring Gear Specifications
   1. With the flywheel friction surface facing up (ring gear down), bore holes for the clutch mounting bolts.
   2. Tap the bore holes with 3/8–16 UNC threads to a minimum depth of 24 mm (15/16 in).
5. Check the ring gear/flywheel radial runout.

   Note: With the ring gear pressed onto the flywheel, make sure the radial runout of the ring gear does not exceed 0.5 mm (0.02 in.).

6. Install the flywheel on the crankshaft flange. Refer to "1.10.2 Flywheel Installation" .