Usage:
The 6V124 Drive Coupling Modification Kit can be installed on any Caterpillar Fuel Injection Test Bench with the above serial numbers. The new drive coupling is stronger and will give better service when testing the fuel injection pump and governor of the larger Caterpillar engines. This instruction gives the procedure needed for the installation of the new drive coupling modification kit as a replacement for the original drive coupling.
Removal of Original Drive Coupling
(1) Disconnect the electrical power from the test bench. Remove the two rear panels.
(2) Remove four screws (1), then remove shroud (2).
(3) Remove rails (3), screw (4) and window (5).
(4) Loosen socket head screw (6) and remove drive coupling (7).
(5) At the rear of the test bench, remove bolt (8) and washer, then remove flywheel (9). [The weight of flywheel (9) is approximately 60 pounds (27).]
(6) Loosen nuts (A), (B), (C) and (D). (The test bench shown has the support straps (10) from the J26794 Stabilizer Kit.)
(7) Remove drive belt (11). If the test bench has a mechanical counter, disconnect (do not remove) drive belt (12) from pulley (13). If the test bench has a digital tachometer, remove bracket (14) and magnetic pick-up (15).
(8) Remove the degree wheel. According to the model of the test bench, the degree wheel will be fastened to the shaft by one of the methods that follow: degree wheel (16) is fastened to the shaft with bolts (17) [some models have only two bolts (17)]; degree wheel (18) is fastened to the shaft with a split clamp, and the clamp screw must be loosened from behind panel (19).
(9) Use forcing screws (20) to remove center bushing (21) and pulley (22).
(10) Loosen two setscrews (23) and move bearing (24) into bearing housing (25). Loosen three bolts (26).
NOTE: For those test benches that have a digital tachometer, do not lose the three non-magnetic bolts (26). If they are lost or damaged, install only non-magnetic bolts of the same part number as a replacement.
(11) Use the three S1615 Bolts (27) from the modification kit as forcing screws and put them in forcing screw holes (E) to break loose the flanged taper-lock bushing.
(12) Loosen two setscrews (28) and use a soft hammer as shown to remove the shaft from the test bench. Remove bearing (29) from shaft (30).
Installation of 6V124 Drive Coupling Modification Kit
Parts in the 6V124 Drive Coupling Modification Kit are as follows.
(1) Put pulley (12) with taper lock bushing, in position as shown. The three bolts that fasten the taper lock bushing to pulley (12) must be loose, not tight. [For test benches that have a digital tachometer, the bolts that fasten the taper lock bushing to pulley (12) must be non-magnetic.]
(2) Install bearing (13) on 6V132 Shaft (2) so face (A) of the bearing is flush (even) with face (B) of the shaft, then tighten setscrews (14). Install 6V128 Key (3) and 6V126 Keys (8).
(3) Install shaft (2). If the test bench has a mechanical stroke counter, shaft (2) must be put through belt (15). If necessary, carefully put a screwdriver in the slot of the tapered bushing (as shown) for easier installation of the shaft. The face of shoulder (C) on shaft (2) must be flush (even) with face (D) of bearing (16). Tighten two setscrews (17).
(4) Use a feeler gauge as shown and move pulley (12) into a position so it is .125" (3.12) from the inner face of bearing (16). Tighten the three bolts (18) that fasten taper lock bushing (19) to pulley (12). If the test bench has a digital tachometer, be sure a flat side, and not a corner, of each bolt (18) is toward the outer diameter of taper lock bushing (19).
NOTE: Bearing carrier (20) is shown out of the test bench for the purpose of illustration only.
(5) For those test benches that have a mechanically driven stroke counter, install pulley (21) and taper lock bushing (22). Install drive belt (15) on pulley (21).
(6) If the test bench is equipped with a digital tachometer, install bracket (23) with magnetic pick up (24) as shown. Angle (E) is approximately 10°.
(7) Install final drive belt (25). Adjust the tension for final drive belt (25) according to the procedure given in step 8.
(8) Install belt tension gauge (26) between the sides of drive belt (25), and in alignment with bottom edge (F) of angle (27). Hole (G) in gauge (26) must face out as shown.
NOTE: Belt tension gauge (26) is the gauge that comes with the test bench.
(9) Adjustment of nuts (H) and (I) at each end of angle (28) is necessary to get the correct tension on drive belt (25). Belt tension is correct when the pin in the plunger of gauge (26) is moved to the center of hole (G) in the gauge. The distance between bottom edge (F) of angle (27) and top edge (J) of angle (28) must be the same at both ends of angle (28). When the belt tension adjustment is correct, the locknut (H) or (I) must be tightened to hold the adjustment.
NOTE: If the test bench is equipped with stabilizer supports (29), nuts (K) and (L) must be loose before adjustment of the drive belt, then tightened after the adjustment procedure is finished. Do not use nuts (K) and (L) to adjust drive belt tension.
(10) Install a 6V128 Key in shaft (2), then install flywheel (30), 1A4512 Washer (9), 6B1125 Lock (10) and 6B1097 Locknut (11). Use 1P2851 Spanner Wrench (31) to tighten locknut (11). Bend tangs (M) of lock (10) to hold locknut (11) in position.
(11) Install degree wheel (32) on shaft (2) according to dimension (N). Dimension (N) is the distance from the rear face of degree wheel (32) to the front face of panel (33) on the test bench. Dimension (N) is as follows: .375" ± .031" (9.5 ± 0.8) for split hub degree wheel.
.219" ± .031" (5.5 ± 0.8) for standard degree wheel that is fastened to a taper bushing.
(12) Install 2B9373 Key (4) in shaft (2). Tighten all bolts in the rear half of drive coupling (1) and install it on shaft (2) as shown. Install 6D4855 Nut Lock (7) and 6D4856 Locknut (6). Use a torque wrench with a 5P3518 Spanner Wrench (34) to tighten locknut (6) to 13 lb.ft. (18). Bend the tangs on nut lock (7) to hold locknut (6) in position.
(13) Assemble the front half of the drive coupling and install it on the rear half.
(14) Install the former rails (35) and window (36) on new 6V133 Shroud (37). Use the former screws to fasten shroud (37) in position on the test bench.
(15) Install the rear panels on the test bench and connect the power source.