TUBE AS 4551863 - Caterpillar

Illustration 1.
Illustration 2.When there is a failure of the bevel gear or pinion, it is our recommendation that replacement be made of both the bevel gear and pinion and that the higher capacity bearing be installed. This is because it is very difficult to thoroughly check a bevel gear or pinion for small cracks or damage.
Normally, when there is a failure of the bevel gear or pinion, the bevel gear shaft can be used again. During disassembly of the bevel gear, runout (total indicator reading) of the bevel gear shaft can be checked to make sure it has not been damaged. With preload on the bearings, check the runout of the smooth back surface of the bevel gear with a dial indicator. The maximum acceptable runout is 0.13 mm (.005"). If the runout of the bevel gear is more than the acceptable limit, check the runout of the bevel gear shaft flange face and outside diameter. See Illustration 1. The maximum runout of the flange face is 0.05 mm (.002") and the maximum for the outside diameter is 0.08 mm (.003").
Changes have been made to the procedures for the installation of the pinion, adjustment of the bearings for the bevel gear shaft, adjustment of backlash and adjustment of tooth contact. Use the new procedures which follow and make a note of these new procedures in your Service Manual.
Installation Of Pinion
Install a new 6T6053 Pinion in the transmission according to the procedure in the Service Manual. Only the information which follows is different from the Service Manual.
1. If desired, a modification can be made to some of the shims to permit easy removal of them when tooth contact is set. See Illustration 3.
Illustration 3.2. Install a complete 3S7146 Shim Pack. It may be necessary later to remove 0.20 to 0.25 mm (.008" to .010") of shims to get the correct tooth contact between the pinion and bevel gear.3. After the pinion has been installed, check to see if the transmission gears on the pinion are free to move towards either end of the shaft. The gears must have at least 0.03 mm (.001") free movement.Adjustment Of The Bearings For The Bevel Gear Shaft
1. Install the bevel gear shaft and the bevel gear with the transmission removed.2. Install full shim packs with both the right and left bearing cages. Install the bolts for the cages. Tighten the bolts to a torque of 100 15 N m (75 10 lb ft).3. Use a dial indicator and a pry bar to check the total movement of the bevel gear and shaft. Make a note of this dimension.4. For machines with the larger bearing, add 0.38 .05 mm (.015 .002") to the dimension found in Step 3. For machines with the smaller bearing add 0.30 .03 mm (.012 .001") to the dimension found in Step 3. This total is the amount of shims that must be subtracted from the shim pack on the left side.5. Install the