Dayco PB1056ST harmonic balancer for the 1968-1977 Pontiac Firebird V8 5.7L, the 1968-1979 Firebird V8 6.6L, the 1971-1976 Firebird V8 7.5L and other vehicles dampens torsional vibration in the crankshaft. It sits on the front of the crankshaft and is sold as a single unit.
- Cast iron outer ring
- Timing marks on the balancer
- Neutral balance with no counterweight
- No integrated pulleys and no crank trigger or exciter plate
Quick facts
- Part: Dayco PB1056ST harmonic balancer
- Also called: engine harmonic balancer
- Fits: the 1968-1977 Pontiac Firebird V8 5.7L, the 1968-1979 Firebird V8 6.6L, the 1971-1976 Firebird V8 7.5L and other vehicles
- Material: Cast iron
- Condition: New
A worn balancer can show up as vibration or a wobble at the front of the engine. With the engine off and cool, look it over for cracks or an outer ring that looks shifted. Other worn parts can cause the same vibration, so rule those out before you replace the balancer.
Fits
Besides the Firebird, the fitment includes the 1968-1978 Pontiac Bonneville V8 6.6L and the 1968-1978 Pontiac Catalina V8 6.6L. Each application takes one. Open the "Vehicles it fits" section and check your own model and engine.
Specifications
Fit and size
- Quantity per vehicle: 1
- Overall outside diameter: 171.50 mm (6.752 in)
- Crank bore: 34.90 mm (1.375 in)
- Nose outside diameter: 47.46 mm (1.869 in)
- Overall width: 82.50 mm (3.249 in)
- Ring width: 29.74 mm (1.171 in)
- Bolt holes: 4
Build and materials
- Outer ring material: cast iron
- Counterweight balance: neutral, no counterweight
- Timing marks: yes
- Integrated pulleys: none
- Crank trigger/exciter plate: not included
- Condition: New
In the box
One harmonic balancer. The Woodruff key, hardware and installation instructions are not included, so plan on new bolts.
Interchange: 594-158S · DA-4551HD
102037 · 872011
This part cross-references / interchanges with the following part numbers:
102037, 594-158S, NA, 872011, DA-4551HD
Frequently Asked Questions
Does the Dayco PB1056ST harmonic balancer fit the 1971-1976 Pontiac Firebird V8 7.5L?
Yes. Dayco PB1056ST fits the 1971-1976 Pontiac Firebird V8 7.5L, the 1968-1977 Firebird V8 5.7L and the 1968-1979 Firebird V8 6.6L. For other models, open the "Vehicles it fits" section.
Does this engine harmonic balancer come with a Woodruff key or bolts?
No. Dayco PB1056ST is the balancer alone. The Woodruff key and hardware are not included, and installation instructions do not come with it.
What are the crank bore and bolt hole count on this balancer?
The crank bore is 34.90 mm (1.375 in) and the balancer has four bolt holes. Its overall outside diameter is 171.50 mm (6.752 in).
Is this balancer neutral balanced, and does it have timing marks?
Yes, it has timing marks. The balance is neutral with no counterweight, and the outer ring is cast iron.
Does Dayco PB1056ST replace the 594-158S number?
Yes. 594-158S is a cross-reference for Dayco PB1056ST, along with DA-4551HD, 102037 and 872011.
