Rod Bearing, .010 Under, forType 1 VW, Kolbenschmidt

OVERVIEW

When it comes to the internal heart of your air-cooled engine, there is zero room for compromise, and that is why the Kolbenschmidt .010 Under Rod Bearing set remains the industry standard for professional engine builders and dedicated VW enthusiasts alike. As an engine ages or sustains wear, the crankshaft journals often require machining to restore a perfectly round and smooth surface. This specific set is precision-engineered for crankshafts that have been ground .010 inches (0.25mm) undersize, ensuring that you maintain the exacting oil clearances necessary for long-term reliability and high-pressure lubrication. Choosing Kolbenschmidt means you are installing a component with the same metallurgical integrity and manufacturing precision that Volkswagen originally specified for their production lines, providing a level of confidence that generic alternatives simply cannot match.

The rod bearings are the primary interface between your connecting rods and the crankshaft, bearing the brunt of every combustion stroke. These Kolbenschmidt bearings are constructed with a high-strength steel backing and a specialized bearing alloy face designed to embed small debris particles, preventing them from scoring the crankshaft journal. This "embedability" is a critical feature for air-cooled engines that may operate in dusty environments or endure high heat cycles. By utilizing these .010 undersize bearings on a freshly turned crank, you effectively reset the clock on your bottom end, providing a stable foundation for everything from a stock 1600cc daily driver to a high-performance weekend cruiser. At Appletree Automotive, we understand that a rebuild is only as good as its weakest link, which is why we point our customers toward the proven durability of Kolbenschmidt internal components.

FITMENT

This rod bearing set is designed for the standard 55mm (nominal) journal found on the majority of Type 1 based air-cooled engines. It is specifically for crankshafts that have been machined .010" (0.25mm) under the standard size. Fits the following applications:

• Volkswagen Beetle: 1954 through 1979 (1200cc, 1300cc, 1500cc, and 1600cc engines).
• Volkswagen Karmann Ghia: 1956 through 1974.
• Volkswagen Bus / Type 2: 1954 through 1971 (Up to 1600cc dual port).
• Volkswagen Type 3 (Squareback, Fastback, Notchback): 1961 through 1973.
• Volkswagen Thing / Type 181: 1973 through 1974.
• Custom Applications: Dune buggies, sand rails, and trikes utilizing a Type 1 VW engine case and crankshaft.

SPECS

Technical specifications for the Kolbenschmidt 113-105-707 rod bearing set include:

• Brand: Kolbenschmidt (Original Equipment Manufacturer Quality).
• Undersize Increment: .010 inches (0.25mm) under standard.
• Crankshaft Journal Diameter: Designed for a 54.75mm ground journal.
• Material Construction: Steel-backed bimetal alloy for superior heat dissipation and load carrying.
• Quantity: Complete set of 8 halves (provides coverage for 4 connecting rods).
• Part Number Reference: 113-105-707 (specifically the .010 / .25mm variant).
• Compatibility: Fits stock VW Type 1, 2, and 3 connecting rods.

PRO TIPS

1. Verify Your Crankshaft Measurements Twice

Never assume the size of your crankshaft journals based on what was previously installed or a verbal note from a machine shop. Before opening the bearing packaging, use a high-quality micrometer to measure each rod journal at multiple points to check for taper and out-of-roundness. For these .010 under bearings, your journal should measure exactly 54.75mm (or 2.1555 inches). Checking this now ensures your oil clearances will be within the factory spec of .001" to .003", preventing oil pressure issues or premature bearing failure down the road.

2. Absolute Cleanliness is Non-Negotiable

The most common cause of immediate bearing failure is "mechanic-induced" debris. When installing your Kolbenschmidt bearings, ensure the backs of the bearings and the connecting rod bores are surgically clean and completely dry. Any piece of lint, dust, or a drop of oil trapped between the bearing shell and the rod can create a "high spot," which leads to localized friction and rapid wear. Clean the crankshaft oil passages with a dedicated galley brush and compressed air to ensure no machining remnants remain from the .010 grind process.

3. Proper Lubrication and Tang Alignment

When seating the bearings into the rods, pay close attention to the alignment of the locking tangs. These tangs are designed to locate the bearing, not to prevent it from spinning (that is the job of the "bearing crush"). Once seated, apply a generous amount of high-quality engine assembly lube specifically formulated for flat-tappet or air-cooled engines to the bearing face. Do not use standard motor oil for assembly, as it can run off the surfaces during the time it takes to finish the build, leaving the bearings dry during that critical first start-up when oil pressure is still building.