It is difficult to turn on toothed clutch or gearbox and it makes loud growl

Engine friction is not completely switched off

Completely switch off friction and gearbox shafts. After turning friction off there should be play with clearance space 3-5mm between release bearing and engine friction levers.

Cardan shaft knocks

The bolting of cardan shaft flange attachment is weak. propeller shaft slip joint is worn out. Universal-joint fork cross and bearings are worn out.

Tighten screws. Change cardanshaft. Change cross and bearings.

Gearbox is heated

Body lubrication level is too low or too high. Clearance space between teeth in cone gears engagement is not sufficient.

Add lubricating oil or remove excess to feeler pin mark or level plug. Adjust gears engagement so you hear steady noise.

Bearings body is heated

Gearings are tightened too hard. Balls (or rollers) jamming in a separator. Foreign particles sticked between the ball and the ring.

Adjust tightening. Change bearing.

Drawworks friction clutch skids

Friction linings are lubricated. Friction linings are worn out.

Remove friction disks, wash with petrol, dry and put back. Change linings.

It is difficult to turn on drawworks frictions. Joints of drawworks chain transmission climb on teeth of star gear. It causes disbalanced functioning of drawworks, followed by jerks and hard hammering.

Ring adjusting nut is tightened excessively. Joints of driving chain star gear are worn down.

Loosen tightening. Change star gear.

Mast is lifted with difficulty.

Jack stem is not moved out completely. It is caused by water freezing in hydraulic cylinder.

Heat jack and oil pressure pipe with steam or hot water. Heat until the mast is up. Then drain water out of pipeline, down the mast and remove water from oil tank. Move stems out, dry and lubricate with solid oil.

When pump is “on” both jack stems will not moved out and safety valve hammering is heard.

Turn off the pump, unscrew the control valve body, check valve.

Mast will not up when the pump is “on” and pressure fluctuates: oil in hydro system is of wrong season viscosity.

Let oilpump work several minutes, so that oil in the tank heated during circulation. Heat oil passages with steam or hot water. Up and down the mast several times, then change oil.

It is difficult to down the mast

Oil is cooled.

Heat the jack and all hydrosystem. Then change oil.