Crankshaft thrust washers Porsche 911 GT3 4.0 and 4.2

The Porsche 911 GT3 4.0 and 4.2 engines

The Porsche MA1.76, MA1.77, MA1.79, MA1.85, MA1.86, MA1.87 and MA2.75 are the 4.0 and 4.2 litre 24-valve engines of the Porsche 911 GT3 (991 and 992 types). For these engines, the manufacturer lists two thrust washer part numbers in standard size, uncoated: the 1T2435, common to all the codes listed, and the 1T2434, specific to the MA2.75 (crankcase index B or C, 3,996 cc). The 4.0-litre (3996 cc) is a naturally aspirated flat-six, with a rev limit of 9,000 rpm on the Porsche 911 GT3 types 991.2 and 992.

Thrust washers

Thrust washers take the clutch thrust and set the crankshaft end play. On a tuned engine with a reinforced clutch, this thrust increases. The uncoated ACL version restores the thrust washers to the original size.

Technical specifications

Technical guide

Each half washer has lubrication grooves on one face. This face fits on the crankshaft side, with the smooth face towards the block or cap. Fitted the wrong way round, the washer deprives the crankshaft bearing face of lubrication and wears it quickly.

Before fitting, coat the crankshaft-side face with assembly grease. Check that the half washers in the block sit flush, fit the cap without forcing it and tighten it following the manufacturer's procedure. Then check the end play with a dial gauge and compare it with the manufacturer's value.

The brand

ACL Bearing Company, an Australian manufacturer of high-performance engine bearings since 1949, supplies uncoated thrust washers for these engines.

Construction and advantages

Vehicle compatibility

These thrust washers fit the Porsche 911 GT3 4.0 and 4.2 engines (engine codes MA1.76, MA1.77, MA1.79, MA1.85, MA1.86, MA1.87, MA2.75) of the following vehicles: