Main bearing set. Porsche 914  ❭  0211984

Steel Backed Main Bearings For VW Type 4 Porsche 914.
Restore dependable crankshaft support and oil-film control during an engine rebuild with these OE Match Steel Backed Main Bearings for VW Type 4 and Porsche 914 engines, available under references 021198493AOST, 021198495AOST, 021198491AOST, 021198483AT, 021198485AT, 021198487AT, and 021198481AT.

Engine: VW Type 4, 411, 412 and Porsche 914

Sizes available:
• STD Case/STD Crank
• STD Case/.010 Crank
• STD Case/.020 Crank
• STD Case/.030 Crank
• .020 Case/ STD Crank/ Thrust+4mm
• .020 Case/ .010 Crank/ Thrust+4mm
• .020 Case/ .020 Crank/ Thrust+4mm

Please Pick size when ordering below

Main bearings are critical internal engine components positioned between the crankshaft main journals and the engine crankcase. They support the crankshaft as it rotates and provide a precisely controlled running surface that allows the crankshaft to operate smoothly on a pressurised film of engine oil. Correct bearing clearances are essential for maintaining oil pressure, reducing friction, controlling crankshaft movement, and protecting both the crankshaft and crankcase.  

What This Product Does:

• Support the crankshaft within the engine crankcase.
• Provide a controlled running surface for the crankshaft main journals.
• Allow the crankshaft to rotate smoothly on a lubricating oil film.
• Help maintain correct crankshaft alignment.
• Help control crankshaft radial movement.
• Support correct crankshaft end float where applicable.
• Reduce direct metal-to-metal contact between the crankshaft and crankcase.
• Help maintain correct engine oil clearances and lubrication.
• Withstand substantial combustion and rotational loads.
• Provide steel-backed construction for strength and dimensional stability.
• Replace worn or unsuitable main bearings during an engine rebuild.
• Suit compatible VW Type 4 and Porsche 914 engine applications.

Symptoms Of Wear Or Failure:

• Low engine oil pressure.
• Oil pressure warning appearing at idle or when the engine is hot.
• Deep knocking or rumbling noises from the lower engine.
• Excessive crankshaft movement or end float.
• Metallic particles or bearing material found in the engine oil.
• Metallic debris discovered in the oil filter or strainer.
• Abnormal crankshaft journal wear.
• Scoring, pitting, or discolouration of existing bearing surfaces.
• Excessive bearing clearance discovered during engine measurement.
• Reduced oil pressure following engine warm-up.
• Evidence of bearing overheating or oil starvation.
• Engine seizure or significant internal damage in severe cases.

Why Replacement Matters:

• Main bearings are fundamental to engine reliability because they support the crankshaft every time the engine operates. The crankshaft is subjected to substantial forces generated by combustion, piston movement, and rotational speed. The bearings must maintain a precise lubricated clearance while supporting these loads.
• As main bearings wear, their running clearance can increase. Excessive clearance may reduce oil pressure and allow increased crankshaft movement, potentially causing knocking, accelerated journal wear, and deterioration of other internal engine components.
• Severely worn or damaged bearings can lose their protective oil film and allow metal-to-metal contact between the bearing and crankshaft journal. This can generate excessive heat, score the crankshaft, damage the crankcase, contaminate the lubrication system with metallic debris, and ultimately result in major engine failure.
• Correct bearing sizing is particularly important when rebuilding a VW Type 4 or Porsche 914 engine. If the crankshaft has been reground or the crankcase has been align-bored, standard-size bearings may no longer provide the required clearances. The correct bearing specification must therefore be selected according to actual crankshaft and crankcase measurements.
• Replacing worn components with the correct OE Match Steel Backed Main Bearings – 021198493AOST, 021198495AOST, 021198491AOST, 021198483AT, 021198485AT, 021198487AT, or 021198481AT helps restore correct crankshaft support, bearing clearance, lubrication, and dependable engine operation when installed as part of a professionally measured and prepared engine rebuild.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

0211984

The product you are viewing cross references to these numbers