Waterboxer Crankshaft Main Bearing Set - 1986-92 - 3 Piece Thrust

This replacement crankshaft main bearing set is designed specifically for 1.9 and 2.1 Waterboxer engines fitted to late Type 25 / T3 Buses. These engines use the later 3-piece thrust bearing design, making this set the correct choice for rebuilds on post-1986 Waterboxer engines.

Main bearings support the crankshaft within the crankcase and maintain precise oil clearances, allowing the crank to rotate smoothly under load. Worn or damaged bearings can lead to low oil pressure, knocking noises, excessive crankshaft movement, and catastrophic engine damage—so renewing them during an engine rebuild is absolutely essential.

What the bearings do and how they work

The crankshaft runs on a pressurised oil film between the bearing surfaces and the crank journals. These main bearings:

• Support the crankshaft radially

• Maintain correct oil pressure

• Control crankshaft alignment

• Work with the thrust bearing to limit crank end float

On Waterboxer engines, correct bearing sizing is critical due to the horizontally opposed layout and sustained load on the crankshaft.

Key specifications (standard size)

For reference, standard main bearing dimensions are:

• Crankshaft (ID): 55mm

• Crankcase (OD): 65mm

Always measure your crankshaft journals and crankcase saddle bores before assembly to confirm standard size is correct.

Kit contents

• 1 × complete main bearing set

• Quantity: 4 bearings (sufficient for 1 engine)

• Includes bearings suitable for 3-piece thrust bearing configuration

Fitment

Vehicles:

• VW Type 25 / T3 Bus

Model years:

• 1986–1992

Engine codes – Waterboxer:

• DF – 1.9

• DG – 1.9

• SP – 1.9

• DJ – 2.1

• SR – 2.1

• MV – 2.1

• SS – 2.1

Important:
Not suitable for early Waterboxer engines with the earlier thrust bearing design. Always confirm engine code and year before ordering.

Recommended related parts

For a proper bottom-end rebuild, consider renewing:

• Main bearing thrust washers

• Big end (con-rod) bearings

• Crankshaft oil seals

• Crankcase through-bolt seals

• Oil pump