What are signs of a bad harmonic balancer?
Documented on the Chevrolet Small Block 350 (sbc 350) build
Published May 25, 2026
Look for visible separation of the rubber isolation layer, wobble when spun, unusual vibrations, or noise.
Full Answer
Look for visible separation of the rubber isolation layer, wobble when spun, unusual vibrations, or noise. A failed balancer can cause excessive engine vibration and accelerated wear.
Documented In This Build
Related Knowledge
What torque should I use on the crankshaft bolt?How do you test an oil pump on the bench?Should I replace the crankshaft seal when installing the balancer?How important is degreeing the cam?What torque sequence and values should I use for SBC heads?How do I set lifter preload or hydraulic lash?What should I do to prepare the engine for first start and break-in?What is the acceptable rod bearing clearance for a Small Block Chevy 350?
Related Parts
Harmonic balancer (damper)
$90
Oil pump (mechanical)
Melling (typical aftermarket)$120
Crankshaft key (Woodruff or rectangular key)
$5
Crankshaft bolt
$10
Front crankshaft seal
$15
Related Tools
Torque wrench
Harmonic balancer installer (press/driver style)
Socket set and breaker bar
Electric drill (for bench-priming oil pump)
Bench vise or pump test fixture
Oil catch container and hoses
Clean rags and assembly lube
Related Videos
Small Block Chevy 350 Build Pt. 6 | This Is How It's Actually Supposed To Be Done
Small Block Chevy 350 Build Pt.3 | Filing rings and checking main clearances
Small Block Chevy 350 Build Pt.5 | Continued frustrations with rod clearances
Small Block Chevy 350 Build Pt. 11 | Installing the intake manifold and figuring out sbc nuisances
Small Block Chevy 350 Build Pt. 7 | Checking Crank Clearance and installing the rods.
Small Block Chevy 350 Build Pt. 8 | Installing Camshaft and timing components