Transmission Bevel Pinion and Transfer Gear for D5, D6, D7, D8, and D9 Tractors with Oval Tracks{1164, 3030, 3159, 3254} Caterpillar

Pipelayer:

561D (S/N: 54X1-UP)

571A (S/N: 64A1-UP)

571F (S/N: 95N1-UP)

572E (S/N: 65A1-UP)

572F (S/N: 96N1-UP)

583H (S/N: 78V1-UP)

583K (S/N: 78V1-UP)

594 (S/N: 62H1-UP; 96V1-UP)

594H (S/N: 96V1-UP)

Track-Type Loader:

977 (S/N: 46H1-UP)

977K (S/N: 46H1-UP)

Track-Type Tractor:

9 (S/N: 45G1-UP)

9U (S/N: 20H1-UP)

D5 (S/N: 83H1-UP; 84H1-UP; 95J1-UP; 96J1-UP)

D5B (S/N: 8HD1-UP; 24X1-UP; 25X1-UP; 44X1-UP; 48X1-UP)

D6 (S/N: 76A1-UP; 10K1-UP)

D6C (S/N: 76A1-UP; 10K1-UP; 24U1-UP; 69U1-UP)

D6D (S/N: 5YB1-UP; 36C1-UP; 9FK1-UP; 75W1-UP; 03X1-UP; 04X1-UP; 06X1-UP; 20X1-UP; 31X1-UP; 32X1-UP; 33X1-UP)

D6E (S/N: 8FJ1-UP)

D6G Series 2 (S/N: 2MJ1-UP)

D7E (S/N: 48A1-UP; 75E1-UP)

D7F (S/N: 61G1-UP; 94N1-UP)

D8 (S/N: 77V1-UP)

D8K (S/N: 77V1-UP)

D9 (S/N: 66A1-UP; 91J1-UP; 90V1-UP)

D9G (S/N: 66A1-UP; 90J1-UP; 91J1-UP; 29N1-UP; 30N1-UP)

D9H (S/N: 12U1-UP; 90V1-UP; 97V1-UP; 98V1-UP; 99V1-UP)

Introduction

© 2012 Caterpillar All Rights Reserved. This guideline is for the use of Cat dealers only. Unauthorized use of this document or the proprietary processes therein without permission may be violation of intellectual property law.

This Reuse and Salvage Guideline contains the necessary information in order to allow a dealer to establish a parts reusability program. Reuse and salvage information enables Caterpillar dealers and customers to benefit from cost reductions. Every effort has been made in order to provide the most current information that is known to Caterpillar. Continuing improvement and advancement of product design might have caused changes to your product which are not included in this publication. This Reuse and Salvage Guideline must be used with the latest technical information that is available from Caterpillar.

For questions or additional information concerning this guideline, submit a form for feedback in the Service Information System. In order to address an urgent issue, use the following resources in order to communicate your request to Caterpillar Repair Process Engineering:

• Caterpillar Dealer Technical Communicator

• Dealer Solution Network

• Caterpillar Technical Representative

• Knowledge Network

Canceled Part Numbers and Replaced Part Numbers

This document may include canceled part numbers and replaced part numbers. Use NPR on SIS for information about canceled part numbers and replaced part numbers. NPR will provide the current part numbers for replaced parts.

Summary

Many worn bevel pinion and transfer gears can be used again after reconditioning. The transmission bevel pinions and transfer gears will normally wear in the splines and the bearing support surfaces. Use the procedures and specifications in this guideline to determine if the worn areas are within the "Use Again" wear limits. If not, use the reconditioning procedures in this guideline.

See Illustration 1 for the location of the transmission output bevel pinion and transfer gear in the transfer gear group.

Illustration 1	g02213873
Transfer Gear Group (1) Bevel Pinion (2) Transfer Gear (3) Bearing (4) Spacer

Measurement of Gear Backlash (Spline Wear)

To determine if the wear on the gear splines exceeds the wear limitations, measure the clearance (backlash) between the bevel pinion and the transfer gear using the following procedure.

1. Put the pinion (gear teeth down) on a metal workbench.

2. Put the transfer gear on the pinion in the same position on the spline as the gear is during normal operation.

   Note: On D8 and D9 Tractors, the large bearing and spacer must be on the pinion. See Illustration 2. On D7 Tractors, the large bearing must be on the pinion. On D5 and D6 Tractors, the transfer gears will go directly on the pinions.

Show/hide table



Illustration 2	g02213893
Bearing and spacer in position on the pinion (3) Bearing (4) Spacer (5) Pinion

3. Use the 8S-2328 Dial Indicator Group to measure the gear clearance. Put a 90° indicator finger in position near the middle of a gear tooth. See Illustration 3.

Show/hide table



Illustration 3	g02213894
Dial indicator in position on a gear tooth (2) Transfer Gear (5) Pinion (6) Dial Indicator

4. With the pinion stationary, turn the transfer gear until the gear will no longer turn. Put the indicator dial on zero. Turn the transfer gear in the opposite direction until the gear will no longer turn. Read the indicator for the amount of gear clearance. For the maximum amount of gear movement when measured near the middle of a tooth, see Table 2. This specification permits a maximum gear movement at the spline area of 0.38 mm (0.015 inch). If necessary, hold the pinion in an arbor press to prevent movement.

5. If the gear movement when measured at the pitch diameter of the transfer gear is more than indicated in Table 2, each part must be measured to see which part has too much spline wear.

Spline Wear of Bevel Pinions

Use the following procedure to measure spline wear on bevel pinions.

1. Put two correctly sized pins opposite each other on the pitch diameter of the spline. For the correct pin size, see Table 2. The locations of the pins must be in the area of the spline that shows wear. To hold the pins in the splines, a rubber band may be put around the spline. Clay may be used also as shown in Illustration 4.

   Note: Bevel pinions on D5, D7, and D8 Tractors do not have an even number of teeth. Consequently, the pins cannot be put directly opposite each other. The dimensions given in Table 2 have been adjusted for this factor.

Show/hide table



Illustration 4	g02214473
Clay is used to hold the pins in the spline. (7) Pin (8) Clay

2. Measure the distance across the pins with an outside micrometer (Illustration 5). Take a measurement at the top and bottom of the worn area of the spline. Put the pins 90° from the first two positions and measure across at the top and bottom of the worn area of the spline.

Show/hide table



Illustration 5	g02214475
Measure the diameter across the pins.

3. The minimum distance across the pins for each of the pinions is given in Table 2. If any of the four measurements are less than the given minimum distance between the pins, the pinion cannot be used again.

Spline Wear of Transfer Gears

Use the following procedure to measure spline wear on transfer gears.

1. Put two pins of the correct size opposite each other on the pitch diameter of the spline. For the correct pin size, see Table 2. The location of the pins must be in the area of the spline that shows wear. Use clay to hold the pins.

   Note: Transfer gears on D5, D7, and D8 Tractors do not have an even number of teeth. Because of this fact, the pins cannot be put directly opposite each other, but must be put in the nearest opposite tooth space. The dimensions in Table 2 have been adjusted accordingly.

2. Measure the distance between the pins with an inside micrometer (Illustration 6). Take a measurement at the top and bottom of the worn area of the spline. Put the pins 90° from the first two positions. Measure the distance again at the top and bottom of the worn area of the spline.

Show/hide table



Illustration 6	g02214873
Measure the diameter between the pins.

3. The maximum distance between the pins for each of the transfer gears is given in Table 2. If any of the four measurements are more than the given maximum distance between the pins, the transfer gear cannot be used again.

Surface Wear on the Bearing Support

A worn bearing support will allow the bearing to turn on the bearing support. The bearing support must be ground to remove the wear, then chrome plated or metal sprayed, and ground to return the bearing support to the original size.

Illustration 7 gives descriptions of the surface areas to be inspected and/or rebuilt on bevel pinions used on D5, D7, D8, and D9 Tractors. Illustration 8 shows the areas on the bevel pinions used on D6 Tractors. The dimensions that are to be used with the illustrations are given in Table 3.

Illustration 7	g02215027
Bevel pinion used on D5, D7, D8, and D9 Tractors

Illustration 8	g02215029
Bevel pinion used on D6 Tractors

Frequently, only the larger bearing support (Diameter A) will need to be chrome plated or metal sprayed. If the smaller bearing support (Diameter B) is worn, the larger bearing support will also be worn.

In bevel pinions used in D5, D7, D8, and D9 Tractors, it is necessary to inspect Face A. The pinion can be salvaged only if the bearing support (Diameter A) is worn and not Face A. If Face A is worn, the bevel pinion cannot be used again.

Face A is used for the location of the large bearing on the pinion. When the transmission is in reverse, the pinion moves toward the large bearing so the flange of the outer race is used for the location of the pinion. If Face A is machined, the position of the mesh between the bevel pinion and gear tooth will change. This position change will change the tooth contact pattern (shape) and cause rapid wear of the teeth and possible failure.

Face A of the pinions used on D6 Tractors can be salvaged by chrome plating or metal spraying because of the design of the pinion. The pinion operates in the same way as the pinions in D5, D7, D8, and D9 Tractors, but Face B is used for the locations of the pinion when the transmission is in reverse instead of Face A. Face B must be inspected carefully and, if worn, the bevel pinion cannot be used again. Face B on pinions in D6 Tractors cannot be chrome plated or metal sprayed.

Mechanical Preparation for Chrome Plating

Use the following procedure to make repairs to bevel pinions.

1. If there is no wear on Face A of the pinion in D5, D7, D8, and D9 Tractors or Face B of the pinion in D6 Tractors, clean the machine centers of the pinion.

2. Before the pinion is installed in an external grinder, a test bar should be machined on the grinder to check for taper. There must be zero taper between the centers of the grinder.

3. Install the pinion in the external grinder. Use the machine centers of the pinion for location. Zero set the pinion by an indication of T.I.R. (Total Indicator Reading). The T.I.R. of the pinion must be zero. Use the area of the bearing support that is not worn for the indication of T.I.R. If both bearing supports are worn, many times there is a part of one of the supports which is not worn and may be used for the indication of T.I.R.

   Note: The indication of T.I.R. of the bearing support is needed to check for worn or damaged machine centers. If the machine centers are worn or damaged, the centers must be machined with a center grinder (if available) or an internal grinder.

4. If all of the surface area of both bearing supports is worn, an indication of T.I.R. will not be possible. The bearing supports will have to be machined without an indication of T.I.R.

5. The worn bearing supports must be machined to a depth that will remove all indications of surface wear. If Face B on pinions in D5, D7, D8, and D9 Tractors or Face A on pinions in D6 Tractors are worn, the faces must be machined to a depth that will remove all indications of surface wear. There must be no indication of grinding errors such as chattering, heat checks, or burning.

Use standard commercial masking, cleaning methods, plating baths, and procedures for the application of hard chrome plating.

Note: Be sure to mask all radii on the pinion. If Diameter B of the pinion used in D5 Tractors is to be chrome plated, the ring groove will need to be filled with wax to prevent chrome plating the groove.

The pinion must be put in an oven at 149° C (300° F) for 3 hours for hydrogen embrittlement relief baking.

After the 3 hours in the oven, remove the pinion and let the pinion air cool slowly to room temperature.

Procedure to Grind Hard Chrome Plating

1. Install the pinion in an external grinder. Use the machine centers of the pinion for the location of the pinion. Zero set the pinion by an indication of T.I.R. Use the same method that was used to grind the pinion before plating.

2. Grind the chrome plating carefully to prevent heat or pressure damage to the plating. Grind the chrome plating with a Norton No. 32-A-80-K5-VBE or a similar grinding wheel with aluminum oxide, 80 grit vitrified bond. Use a large volume of cutting fluid, either heavy-duty synthetic or light soluble oil. Use wheel speeds of 1980 surface meters per minute (6500 surface feet per minute) to 2590 surface meters per minute (8500 surface feet per minute) and a medium to high work speed to prevent heat damage. Stock removal must be limited to a maximum of 0.05 mm (0.002 inch) per pass.

Salvage by Metal Spray

Worn or damaged surfaces designated to be salvaged by chrome plating can also be salvaged by a metal spray process. Refer to:

• Reuse and Salvage Guidelines, SEBF9238, "Fundamentals of Arc Spray for Reconditioning Components"

• Reuse and Salvage Guidelines, SEBF9240, "Fundamentals of Flame Spray for Reconditioning Components"

• Reuse and Salvage Guidelines, SEBF9236, "Fundamentals of HVOF Spray for Reconditioning Components"

Dimensions for Final Machining

Machine the rebuilt bearing supports to Diameters A and B in Table 3. If the face on the pinion used for bearing location was rebuilt, grind the face to the dimension given under Length G. The dimensions for all of the radii must be the same as given in Table 3. Grind the chamfer for the bearing supports to the dimensions given in Table 3. Diameter B on pinions in D5, D7, D8, and D9 Tractors must be concentric with Diameter A within 0.03 mm (0.001 inch) T.I.R. The chrome plated or metal sprayed faces, that are used for bearing location, must be square with the center line of the pinion within 0.08 mm (0.003 inch) T.I.R. The surface finish of the bearing supports must be no more than 1.6 µm (63 µ inch).