Check these first
- Swing motor mounting bolts. On several 1-tonne machines they are small (often 14 mm heads) and arrive loose. Check them in the first few hours and again regularly.
- Slew bearing bolts. Some machines have them above and below the bearing, with the upper set buried under hydraulic lines; a ball-end extension helps.
- Grease on the slew ring gear and bearing.
It will not turn at all
- If the hose to the swing motor jumps when you push the lever but nothing moves, the motor is getting pressure. Look for a pinion that has come off its shaft, a sheared shaft or a stripped mounting.
- If nothing happens and the hoses do not move, check the valve section and the swing lever linkage.
- Some machines have a swing lock pin or brake. Check that it is released.
It squeaks, grinds or sticks
- The slew bearing usually has two grease fittings under the upper frame, sometimes recessed. A needle-tip grease adaptor reaches them.
- Grease in stages: a few shots, rotate about a quarter turn, repeat until you have gone all the way round. Grease the ring gear teeth the same way.
- Many machines arrive with dry bearings and pins, so a squeak on a brand-new machine is a grease issue first.
Preventing failures
- Stop swings gently. A cushion valve on the swing circuit absorbs the shock of sudden stops; owners fit it to save the motor, shaft and bolts.
- Do not sweep dirt or push logs sideways with the arm out. The side load goes straight into the small swing pinion.
- Keep the arm and bucket tucked in when swinging with a load.
Stay safe: Switch off and lower the bucket before working near the slew ring. The upper can move if a valve leaks.