Sierra 18-15115 Serpentine Belt for MerCruiser
- Brand:
- Sierra
- Part no:
- 18-15115
Where to buy
View on Amazonpaid link
This Sierra serpentine belt is made for MerCruiser engines. It measures 13/16 inch wide and 97.5 inches long. Sierra gives it as a replacement for Mercury part 57-861757Q, so check that number against your old belt. Both dimensions are the first things to compare with the belt already on the engine, and the Sierra number to match is 18-15115.
Our take
At 97.5 inches long and 13/16 inch wide, the Sierra 18-15115 is a defined size you can check with a tape against the belt on the engine. It replaces Mercury 57-861757Q, so that number is a quick cross-check.