Sierra 18-15115 Serpentine Belt
- Brand:
- Sierra
- Part no:
- 18-15115
Where to buy
View on Amazonpaid link
This is Sierra's 18-15115 serpentine belt for MerCruiser engines. It is 13/16 inch wide and 97.5 inches long. It is made to replace Mercury part numbers 57-861757 and 57-861757Q, which gives you a number to match against the belt now on your engine.
Our take
At 97.5 inches long and 13/16 inch wide, the 18-15115 is a defined size, and it replaces Mercury 57-861757 and 57-861757Q. Measure your old belt or read the number off it, because the length has to match.