ITALKIT Crankpin 18x40 mm

The ITALKIT 18x40 mm BUC.18.40 crankpin is a universal part. The crankpin joins the two crankshaft flywheels and the big end of the connecting rod runs on it. It takes the full force of combustion: it is changed together with the rod and its needle bearing when a crankshaft is rebuilt.

Specifications

• Brand: ITALKIT
• Manufacturer part number: BUC.18.40

When to replace it?

• Vertical play at the big end at top dead centre.
• Crankpin marked, blued or pitted on teardown.
• Dull knock from the bottom end that gets louder under load.

Every time the connecting rod is replaced: a worn crankpin destroys a new needle bearing within a few hours.

Fitting tips

1. Note the dimensions of the old crankpin (diameter, length, shoulders) before ordering.
2. The crankpin is pressed into the flywheels: the job needs a press and a truing stand.
3. After assembly, check the crankshaft runout with a dial gauge, i.e. the wobble measured at the end of the shaft, which must stay within a few hundredths of a millimetre.
4. Have the rebuild done by an equipped workshop if you don't have this equipment.

Spare parts and items to plan

• Connecting rod kit : see the selection
• Complete engine gasket kit : see the selection

Frequently asked questions

Does it come with the connecting rod?
No: this is the crankpin only. It is fitted with a connecting rod and a big-end needle bearing of matching dimensions.

How do I choose?
By its dimensions: diameter and length of the original crankpin, or those given by the connecting rod manufacturer.

Compatibility

Universal part: check the dimensions given before ordering.