ACL High Performance Standard Size Main Bearing Set, #5 Thrust Bearing Position Subaru WRX 2002-2014 / STI 2004-2021 | 5M8309H-STD

ACL's main bearings are crafted from a softer metal. This helps protect your crank and engine block from wear. A thin oil layer lubricates the connection between the bearings and the crank. This allows the crank to 'float', reducing wear significantly. Proper support from these main bearings is vital. It prevents oscillations and wear that can harm the crankshaft and other components as the engine goes out of balance. Bearings with extra oil clearance can handle the stress of high - horsepower motors better. However, they experience more wear during startup. We suggest these be bought only by experienced professionals. Note that Subaru main bearings are for either #5 or #3 journal bearing positions. The journal bearing position isn't related to VIN or year. You must know it before buying. Engine internals aren't eligible for exchange or return, so choose carefully.

Using these ACL main bearings is straightforward. First, make sure you know whether you need the bearings for the #5 or #3 journal bearing position. This information is crucial and should be determined before installation. When installing, ensure the bearings are properly seated to provide the best support for the crankshaft. For high - horsepower motors, the bearings with extra oil clearance are a good option, but keep in mind they wear more during startup. As for maintenance, regularly check the oil level and quality. Clean oil helps the bearings work smoothly and reduces wear. If you notice any unusual noises or performance issues, it's a good idea to inspect the bearings. Remember, these are engine internals, so if you're not an experienced professional, it's best to get help from someone who is. And don't forget, once you've installed these bearings, they can't be exchanged or returned, so double - check your needs before purchase.