Big end conrod bearings, SET OF 12. Porsche 993 / 996 Turbo Oversize 0.25mm › 99310314753

OE Match big end conrod bearings for Porsche 993 and 996 Turbo applications, supplied as a SET OF 12 in the Oversize 0.25mm specification. These replacement shells are intended for correctly measured engine rebuilding work.

Fits

Porsche 993 1994-98

Check fitment for your specific vehicle (model, year, engine) before ordering.

Diagram ref no: 15

What This Product Does

The bearing shells sit within the connecting-rod big ends, forming the lubricated interface with the crankshaft journals. Correctly selected bearings support rod movement and distribute combustion loads while maintaining the oil clearance required by the engine specification.

Functions

• Provide a bearing surface between each connecting rod and its crankshaft journal.
• Support lubricated movement at the big-end connection.
• Distribute loads transmitted through the connecting rods.
  
  

Technical Details

• Brand: OE Match.
• Product reference retained from the supplied information: 71-3775/6.
• Connecting-rod bearing reference: 99310314753.
• Specification: Oversize 0.25mm.
• Contents: SET OF 12 bearing shells.
  
  

Symptoms of Fault

• A deep knock or rumble, particularly when the engine is loaded.
• Oil-pressure warnings or pressure falling as the engine warms.
• Metal particles discovered during oil or filter inspection.
• Scoring or uneven wear found on dismantled bearing surfaces.
  
  

These findings require diagnosis; none identifies a bearing fault conclusively on its own.

Why Replacement Matters

Renewing worn shells during an engine rebuild allows the builder to establish suitable bearing clearances and inspect the crankshaft and rods for associated damage. Any underlying lubrication problem, contamination or overheating must also be investigated rather than addressed by bearing replacement alone.

FAQs

Can these be selected by vehicle model alone?
No. The listed application must be checked alongside the measured crankshaft journals and the required bearing specification. Oversize 0.25mm must not be assumed suitable for every rebuild.

What needs checking before installation?
Inspect the journals and connecting rods, measure the assembled clearances and investigate the cause of existing wear. A competent engine builder should confirm the final selection.

Does low oil pressure always mean worn bearings?
No. It is a reason to investigate the lubrication system and internal condition, not proof that these shells require replacement.