Bearing Preload Adjustment

It is not necessary to reestablish preload shim thickness when new bearings are installed. It is only necessary to establish preload shim thickness when a transmission housing component, gear shaft, or differential is replaced. This procedure is used to measure zero end play of the gear shafts and differential in the C635 (Manual or DDCT) transmission and establish the proper thickness of the select shims placed behind the bearing races in the transmission housing to apply specific bearing preload to prevent bearing failure and gear rattle.

Transmission Preparation

1. Clean the transmission with suitable solvent.
2. Install new bearings on the gear shafts and the differential.
   Fig 1: Removing Preload Bearing Races

   Courtesy of CHRYSLER GROUP, LLC
3. Remove the bearing races (2) from the transmission housing using tools Bearing Cup Remover (1) (special tool #9664, Remover, Bearing Cup) and Universal Slide Hammer (special tool #C-637, Slide Hammer, Universal).
4. Remove the factory installed select shims from the transmission housing. Mark the shims to identify the bore that they were removed from.
5. From the circumference of the original bearing races, grind 0.18 mm (0.007 in) material from the races to allow them to slip-fit into the transmission housing.
   NOTE:

   To ensure a flat uniform surface on the Outside Diameter (OD) of the bearing races, chuck them on a suitable (brake) lathe and remove material from the OD with a suitable die grinder.

6. Insert the, reduced OD, differential bearing race into the transmission housing.
   NOTE:

   No select shim is required to measure the differential zero end play.

   Fig 2: Starter Shims & Plastigauge®

   Courtesy of CHRYSLER GROUP, LLC
7. Insert an 0.80 mm (0.031 in), or suitable thickness, starter shims (2) in each gear shaft bearing race bore in the transmission housing. This will create measurable gear shaft end play after the transmission cases are assembled.
   NOTE:

   If the original shims are greater than 1.32 mm (0.052 in) thick, use a 1 mm starter shim.

8. Use RED Plastigauge®, cut in 6 mm (1/4 in.) lengths (1), placed 120 degrees apart around the side surface of the select shims.
   NOTE:

   If the gear shaft end play is less than the RED Plastigauge® can accurately measure, use GREEN Plastigauge®.

9. Install the reduced diameter bearing races in the bores in the transmission to capture the Plastigauge®.
   Fig 3: Differential Assembly In Bellhousing

   Courtesy of CHRYSLER GROUP, LLC
10. Install the differential assembly in the clutch housing half of the transmission housing.
11. Place the bearing race plate in position on the clutch housing half of the transmission housing.
12. Install the bolts to hold the bearing race plate to the clutch housing. Tighten the bolts to torque spec.
    Fig 4: Three Gear Shafts In Bellhousing

    Courtesy of CHRYSLER GROUP, LLC
13. Install the three gear shafts in the clutch housing half of the transmission housing.
14. Install the transmission housing onto the clutch housing.
    NOTE:

    If the reduced diameter bearing races slip out of the bearing bores, Door Ease® wax can be applied to the circumference of the race to adhere it to the bore.

    Fig 5: Transmission Housing To Clutch Housing & Transmission Case Halves Bolts

    Courtesy of CHRYSLER GROUP, LLC
15. Install four bolts (1) to hold the transmission housing to the clutch housing around the differential side of the transmission. Tighten the bolts to 50% of the torque specification.
16. Turn the transmission on its side to gain access to the inside of the clutch housing.
17. Install seven bolts (2), four above and three below the gear shafts, to hold the transmission case halves together, Tighten the bolts to 50% of the torque specification.
18. Turn transmission, clutch housing downward, on the work surface.

Measuring Differential End Play

1. Install (special tool #C-4995A, Tool, Differential Bearing Torque) (1) into the differential side gear (2).
   Fig 6: Installing Special Tool To Differential Side Gear

   Courtesy of CHRYSLER GROUP, LLC
2. Clamp a typical vise grip pliers (4) on tool (special tool #C-4995A, Tool, Differential Bearing Torque) (2).
3. Attach dial indicator (1) (special tool #C-3339A, Set, Dial Indicator) to transmission housing with the plunger placed on the end of tool (special tool #C-4995A, Tool, Differential Bearing Torque) (2).
   Fig 7: Measuring Differential End Play

   Courtesy of CHRYSLER GROUP, LLC
4. Zero the indicator dial (1).
5. Use a large screw driver (3) to pry upward on tool (special tool #C-4995A, Tool, Differential Bearing Torque) (2) to take up the bearing free play.
6. While holding tool (special tool #C-4995A, Tool, Differential Bearing Torque) (2) upward read the dial indicator (1).
7. Add 0.15 mm (0.006 in.) to the dial indicator reading.
8. The sum is the proper thickness of the differential preload shim.

Measuring Gear Shaft End Play

1. Turn the transmission on its side to gain access to the inside of the clutch housing.
   Fig 8: Transmission Housing To Clutch Housing & Transmission Case Halves Bolts

   Courtesy of CHRYSLER GROUP, LLC
2. Remove the bolts (2) holding the clutch housing to the transmission housing.
3. Turn transmission, clutch housing downward, on the work surface.
4. Remove the remaining bolts (1) holding the clutch housing to the transmission housing.
5. Place the transmission housing on the work surface inside up.
   Fig 9: Bearing Race, Shim & Plastigauge®

   Courtesy of CHRYSLER GROUP, LLC
6. Using a hook tool, remove the reduced size bearing races (4). Be careful not to damage the Plastigauge® (2).
7. Compare the thickness of the Plastigauge® (2) to the RANGE template on the Plastigauge® packaging (1).
8. Add the Plastigauge® RANGE thickness, plus 0.15 mm (0.006 in.) to the thickness of the starter shim used to create gear shaft end play.
9. The sum is the proper thickness to preload for each of the gear shaft bearings.
10. Install the closest thickness shims from the list provided by Mopar® Parts.
    NOTE:

    If the measured thickness falls between the shim thicknesses provided by Mopar® Parts, install the shim that is slightly thicker.

After proper bearing preload is established, finish assembling the transmission.