Fault Phenomenon: Caterpillar D6N dozer when driving on uneven roads, a “clunking” impact sound comes from the rear axle area.

Troubleshooting Process:
– Checked equalizer beam: bushings connecting the equalizer beam to the frame worn or cracked.
– Checked pins: pins worn with steps.
– Checked lubrication: grease fittings clogged, lack of lubrication.
– Checked bolts: mounting bolts loose.

Root Cause: The rear axle equalizer beam suspension bushings, due to long-term lack of lubrication and impact loads, have rubber aging/cracking or metal bushing wear.

Required Parts: Rear axle equalizer beam bushing assembly.