Differential Thrust Washer Selection

Fig 1: Identifying Differential Thrust Washer Selection

Courtesy of GENERAL MOTORS CORP.

Callout	Component Name
NOTE: Improper thrust washer selection can cause insufficient taper bearing pre-load which will cause premature failure of the front differential drive pinion gear.
1	Front Differential Bearing Washer Tip: Place DT 47800-7 in the gap in DT 47800-2 which are both part of DT-47800 , to determine the proper thrust washer. See Special Tools . Choose the correct thrust washer. Refer to Taper Bearing Preload Selective Specifications . Tip: Continue trying different sizes of DT 47800-7 which is part of DT-47800 , until the gage will no longer fit into the gap. See Special Tools . The correct thrust washer size is equal to the largest blade gage that fits into the gap. Match the size of the correct DT 47800-7 blade which is part of DT-47800 , to the color code in the thrust washer specification chart. See Special Tools . The washer color coding is on the outside diameter of the washer. The gap in DT 47800-2 which are both part of DT-47800 may not be even. See Special Tools . Hold the top of the gage and rotate the bottom of the gage to even out the gap. Take two gap measurements 180 degrees apart. Average the two measurements and select the thrust washer that is closest to the average. The washer color coding is on the outside diameter of the washer. Special Tool: DT-47800 Thrust Washer Selection Gage Kit. See Special Tools .
2	Front Differential Drive Pinion Gear Bearing Thrust Washer IMPORTANT: Place DT 47800-7 in the gap in DT 47800-1 which are both part of DT-47800 , to determine the proper thrust washer. See Special Tools . Choose the correct thrust washer. Refer to Taper Bearing Preload Selective Specifications . Tip: Continue trying different sizes of DT 47800-7 which is part of DT-47800 , until the gage will no longer fit into the gap. See Special Tools . The correct thrust washer size is equal to the largest gage that fits into the gage. Match the size of the correct DT 47800-7 blade which is part of DT-47800 to the color code in the thrust washer selection chart. See Special Tools . The gap in DT 47800-1 which is part of DT-47800 may not be even. See Special Tools . Hold the top of the gage and rotate the bottom of the gage to even out the gap. Take two gap measurements 180 degrees apart. Average the two measurements and select the thrust washer that is closest to the average. The washer color coding is on the outside diameter of the washer. Special Tool: DT-47800 Thrust Washer Selection Gage Kit. See Special Tools .
3	Torque Converter and Support and A/Trans Fluid Pump Housing Assembly Procedure Remove DT 47800-3 which are both part of DT-47800 , bolts and spacers. See Special Tools . Remove the torque converter housing. Remove DT 47800-1 and DT 47800-2 which are both part of DT-47800 . See Special Tools . Remove the torque converter housing seal. Remove the pinion gear and differential bearing cups. Install the bearing cups and thrust washers into the torque converter housing per the replacement procedures. Refer to Front Differential Carrier Bearing Cup and Washer Replacement - Torque Converter Housing Side and Front Differential Drive Pinion Gear Bearing Cup and Lubricant Dam Replacement . Tip: DT 47800-1 and DT 47800-2 which are both part of DT-47800 , may stick in the torque converter housing. See Special Tools . Be careful not to drop the gages. Special Tool: DT-47800 Thrust Washer Selection Gage Kit. See Special Tools .