Tilt Cylinder Piston Nut May Loosen on 973D Track-Type Loaders{5104} Caterpillar

Introduction

The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.

Problem

The piston nut for the tilt cylinder may loosen on the machines listed above. The loose nut can result in damage to cylinder. Particles from the cylinder damage may infest the rest of the hydraulic system and cause collateral damage to the rest of the components.

Note: AVSpare highly recommends the tear down of the second tilt cylinder for analysis and inspection of the piston backing off. Without checking the unfailed second tilt cylinder, there is a risk of having another failure upon replacement and installation of the failed cylinder. The cylinder stroke lengths and load sharing between the cylinders will certainly be off when the machine is put back into service.

Solution

AVSpare is aware of this problem, but an interim repair has not been defined.

In the event of failure, replace the failed components with the existing part that are listed in Table 1.

Use the following procedure in order to assemble the piston into the hydraulic cylinder rod assembly:

Show/hide table



Illustration 1	g03721551

1. Before assembly, ensure the internal threads of piston (A) and external threads of cylinder rod assembly (B) are clean of oil and contaminants.

2. Use Loctite 243, shake the product thoroughly before applying.

3. To prevent clogging of the Loctite 243, DO NOT allow the tip to touch the metal surfaces during application.

4. Apply several drops of Loctite 243 to threads of cylinder rod assembly (A), where the piston (B) will engage.

5. Assemble all components accordingly and tighten piston (B) to 5000 ± 250 N·m (3688 ± 184 lb ft).

6. Allow the assembly to set for a minimum of 6 hours to achieve 80% strength or a full 24 hours to ensure proper cure.