NUT-JAM 4Z8719 - Caterpillar

Removal Procedure
Start By:
Separate the track assemblies.
Illustration 1 g00708892
The spring of the recoil spring assembly is compressed under several tons of force.Do not attempt to compress or release the tension of the spring with the nut on the end of the retaining rod.Damaged threads on the retaining rod or nut can cause the assembly to come apart with force, resulting in injury or death.
Use a pry bar and move the front idler (1), the recoil spring, and the hydraulic track adjuster partially out of the track roller frame. Attach a suitable lifting device to front idler (1), as shown.
Illustration 2 g00708894
Once front idler (1), the recoil spring, and the hydraulic track adjuster (2) is partially out of the track frame reposition the suitable lifting device in order to support the recoil spring, the hydraulic track adjuster, and the front idler.
Slide the front idler, the recoil spring, and the hydraulic track adjuster (2) out of the track roller frame as one unit. The weight of the unit is approximately 204 kg (450 lb).
Leave the suitable lifting device attached and turn the front idler, the recoil spring, and the hydraulic track adjuster around 180 degrees.
Illustration 3 g00708895
Install the front idler partially into the track frame. The front idler, the recoil spring, and the hydraulic track adjuster will be supported by the track frame.
Reposition the suitable lifting device in order to support the recoil spring and the hydraulic track adjuster (2).
Remove bolts (3) that hold the front idler to the recoil spring and the hydraulic track adjuster together.
Separate recoil spring and the hydraulic track adjuster (2) from the front idler. The front idler will be supported by the track frame.
The weight of the recoil spring and the hydraulic track adjuster as a unit is approximately 95 kg (210 lb).
Illustration 4 g00708896
Attach a suitable lifting device to front idler (1), as shown.
Remove front idler (1) from the track roller frame. The weight of front idler (1) is approximately 109 kg (240 lb). Reference: Refer to Undercarriage Reconditioning Bulletin, SEBF8495, "Hydraulic Excavator Idler Disassemble and Assembly Procedures" for the disassembly and assembly procedures for the idler.Installation Procedure
Install the front idler (1) and recoil spring in the reverse order of removal.
Tighten bolts (3) to a torque of 240 40 N m (177 30 lb ft).