1998/11/16 Caterpillar

773B Off-Highway Truck

Description of Change: The Lock Up Clutch may start to slip mid life after rebuild. A pressure check may indicate that the pressure is correct at point the point of engagement when measured at the pressure tap on the LUC valve. There may still be leakage of pressure oil in the oil passage toward the piston. When prolong slippage occurs, there will be gradual deterioration of the friction disc surface until the correct clutch engagement is achieved.

Illustration 1.
Parts location.

When rebuilding the torque converter, check the following items for wear to ensure longer rebuild service life.

* Look for signs that the 6V-9191 Bearing (3) has been fretting or rotating on the 1T-1359 Hub (4).

* Check for wear on the 1T-1616 Washer (bellville) (1) and the 1T-1617 Retainer Plate (2) that locates the bearing.

NOTE: Excess clearances in this area will allow clutch oil pressure to leak.

Check the dimensions of the following parts for proper tolerances:

Illustration 2.
1T-1616 Washer (1).

* The dimensions of the 1T-1616 Washer (1) to check:

Thickness (A) 5.0 ± .13 mm (.2 ± .005 in)

Free Height (B) 6.1 mm (.24 in)

Illustration 3.
1T-1617 Plate (2).

* The dimensions of the 1T-1617 Plate (2) to check:

Thickness (C) 13.5 ± .5 mm (.53 ± .02 in)

Washer Turn Depth (D) 5.69 ± .05 mm (.224 ± .002 in)

Illustration 4.
1T-1359 Hub (4).

* The dimension of the 1T-1359 Hub (4) to check:

Bearing Turn Depth (E) 24.66 ± .15 mm (.97 ± .006 in)

NOTE: Replace any components that are out of tolerance during the rebuild process.

Adaptable To: 773B (63W4040-UP)