OTC Valve Spring Compressor OTC 4573 — Universal 5-7/8" Throat, Adjustable Jaw for Installed Cylinder Heads

Designed for technicians working on cars, vans and light trucks, the OTC 4573 makes it possible to service valve springs in tight engine bays without removing the head. Its spring-loaded jaws grip springs securely while offset legs maintain vertical alignment, and two adapters extend compatibility for a wide range of retainers. Built to deliver dependable performance on the bench or in the engine compartment, this compressor balances reach, jaw capacity and throat clearance to handle most routine valve service tasks.

How does the OTC 4573 let me work in tight underhood spaces?

The tool's compact throat and reach are engineered for access where larger compressors won't fit. A 5-7/8 inch throat clearance and a jaw opening that adjusts from 1-3/8 to 5-5/8 inches let you position the tool over installed cylinder heads and compress springs without extensive disassembly.

• 5-7/8 inch throat clearance for deeper access into the engine bay
• Adjustable jaw opening from 1-3/8" to 5-5/8" to fit a wide range of spring sizes
• Compact footprint suitable for vehicles with limited underhood space

What features keep the spring compressor stable and safe during use?

Stability comes from spring-loaded jaws and offset legs. The jaws automatically clamp and hold spring retainers while the built-in leg offset compensates for spring wind so the tool stays vertical and reduces slippage during compression.

• Spring-loaded jaws provide consistent gripping force on retainers
• Legs with built-in offset counteract spring wind and maintain vertical alignment
• Includes two spring adapters to seat varying retainer shapes securely

Which valve spring sizes and retainers does it support?

The OTC 4573 covers most common passenger vehicle applications with broad jaw range and included adapters. It accepts retainers up to 1-13/16 inches in diameter and adapts to both small- and mid-size springs using the supplied adapters.

• Fits valve spring retainers up to 1-13/16" diameter
• Jaw opening spans 1-3/8" to 5-5/8" for broad compatibility
• Two included adapters help secure varying retainer profiles

Can I use this compressor for bench work as well as installed heads?

Yes — the OTC 4573 is versatile enough for both in-situ engine service and bench jobs. Its combination of throat clearance, jaw travel and adapter options lets you work on installed cylinder heads or remove components and perform spring work on a bench fixture.

• Designed for installed cylinder heads and bench applications
• Durable construction for repeated shop use
• Compact and portable for moving between bays or workstations

Who is this for: The OTC 4573 Universal Overhead Valve Spring Compressor is intended for professional technicians, independent mechanics and experienced DIYers who need a reliable, compact tool for valve spring removal and valve stem seal service on cars, vans and light trucks. Its measured throat clearance, broad jaw range and included adapters make it a practical choice for shops that require a single tool to handle many routine valve service tasks without sacrificing access or stability.