1998/03/09 Caterpillar

Improved Cylinder Rod Extension Procedure{4197}

Usage:

Challenger 65D (2ZJ1965-Up),
Challenger 65E (6GS),
Challenger 75C (4KK2398-Up),
Challenger 75D (5AR) Challenger 75E (6HS),
Challenger 85C (9TK1970-Up) Challenger 85D (4GR) Challenger 85E (6JS),
Challenger 95E (6KS) Agricultural Tractors

NOTE: The following information replaces the procedure Service Manual Module, Systems Operation, Testing & Adjusting; SENR1734-00; Challenger 65E, Challenger 75E, Challenger 85E, and Challenger 95E Agricultural Tractors Power Train "Measure Cylinder Rod Extension".

NOTE: The following information replaces the procedure Service Manual Module, Systems Operation, Testing & Adjusting; SENR8472; Challenger 65D, Challenger 75C, and Challenger 85C Agricultural Tractors Undercarriage, Steering and Brakes "Measure Cylinder Rod Extension".

NOTE: The following information replaces the procedure Service Manual Module, Systems Operation, Testing & Adjusting; SENR9438; Challenger 65D, Challenger 75D, and Challenger 85D Agricultural Tractors Undercarriage, Steering and Brakes "Measure Cylinder Rod Extension".

1. Check and make sure that bogie suspension springs are correctly inflated.

2. Clean the undercarriage.

3. Move the machine forward without steering. Allow the machine to stop without using the service brake pedal.

4. Move the transmission control lever to the NEUTRAL position and engage the parking brake.

5. Stop the engine.

6. Check the nitrogen charge pressure and adjust if needed.

NOTE: See, "Test and Charge the Tensioner Cylinder" to get the correct nitrogen charge in relationship to temperature.

7. Measure the length of the tensioner cylinder from the centerline of one retainer pin hole to the centerline of the other retainer pin hole to get Dimension (A). Check dimension (A) on both cylinders.

On the Challenger 65E, Challenger 75E, Challenger 85E, and Challenger 95E Agricultural Tractors, dimension (A) should be 1216 ± 11 mm (47.87 ± .43 in).

On Challenger 65D, Challenger 75C, Challenger 75D, Challenger 85C, Challenger 85D Agricultural Tractors, dimension (A) should be 1238 ± 11.0 mm (48.47 ± .43 in).

8. If dimension (A) is not correct, record the dimension for later use.

9. For Challenger 65D (2ZJ1965-2092), Challenger 75C (4KK1-2397), Challenger 85C (9TK1-1969) Agricultural Tractors, add or remove shims in order to bring Dimension (A) within the tolerance. The shims are located between the tensioner bracket and the front axle.

10. Later machines have no shims under the front axle bracket. On these machines, the belt tension can be adjusted by changing the nitrogen pressure in the belt tension cylinders. If Dimension (A) is less than the specification listed in Step 7 for your machine, increase the nitrogen pressure by 28.9 kPa (4.2 psi) for each 1 mm (.04 in) that Dimension (A) is below specification listed in Step 7 for your machine.

Depending on the machine in question, see Chart B or Chart C in order to calculate the correct pressure change for your machine.

Example:

On a Challenger 65D that has Dimension (A) as 1228 mm (48.35 in), the nitrogen pressure should be increased by 289.4 kPa (42.0 psi) above the nominal pressure. The nominal pressure is calculated from Chart A. The pressure change for a Challenger 65D is calculated from Chart B.

In this example, if the ambient temperature of the machine 10°C (50°F), Chart A indicates that the nominal pressure should be 1872 kPa (263 psi). Therefore, the pressure increase from Chart B should be 289.4 kPa (42.0 psi). The final pressure will be: 263 psi + 42 psi = 305 psi.

The increase in pressure will increase belt tension equivalent to a tension cylinder of the correct extension length.

NOTE: Regardless of the measurement of Dimension (A), do not add more than 347.3 kPa (50.4 psi) above the nominal pressure.