Valve Spring: Testing and Inspection

INSTALLED HEIGHT





Measure assembled height of valve spring from top of spring seat to underside of valve spring retainer with dividers. Check dividers against a scale. If assembled valve spring height is greater than 39-40 mm (1.535-1.575 inch), install necessary spacers between cylinder head spring seat and valve spring.

LENGTH INSPECTION





- Inspect each valve spring for cracks or damage and replace as necessary.
- Measure the free length of each valve spring as shown. If not approximately 46.8 mm (1.84 inch), replace the valve spring.

TENSION





- Weak valve springs cause poor engine performance. Inspect the valve spring, valve spring retainers, valve spring retainer keys and sleeves for wear or damage. Discard any damaged parts.

NOTE:
- Make sure the valve springs are reassembled to their OWN ORIGINAL DAMPERS by pushing damper on the valve spring. DO NOT OPEN damper with any kind of tool when reassembling.
- Manually rotating the valve spring assemblies while installed in the engine will not determine condition of valve springs.

- Check valve springs for proper pressure at the specified spring lengths using Valve/Clutch Spring Tester TOOL-6513-DD or equivalent. Replace any valve spring not within 680 N @ 30.19 mm (153 lbs @ 1.18 inch).

Service Limit
Pressure Loss @ Specified Height 10% @ 30.09 mm (1.85 inch).

SQUARENESS
NOTE:
- Make sure the proper color-coded valve spring is installed.
- Make sure the valve springs are reassembled to their OWN ORIGINAL DAMPERS by pushing damper on the valve spring.
- DO NOT OPEN damper with any kind of tool when reassembling.
- Check new valve springs before installation.





1. Check each valve spring for squareness, using a steel square and a flat surface.
2. Stand the valve spring and square on end on the flat surface.
3. Slide the valve spring up to the square.
4. Revolve the valve spring slowly and observe the space between the top coil of the valve spring and the square.
5. Maximum Out-Of-Square: 1%.