REMOVAL & INSTALLATION
Valve spring removal is part of the valve and/or valve stem seals procedures found earlier in this section. If necessary to remove one or more valve springs with the cylinder head installed, follow the procedure found under Valve Stem Seals.
See Figures 1 and 2
- Check valve spring tension with Tool J-8056 or equivalent spring tester.
Springs should be compressed to the specified height and checked against the specifications chart. Springs should be replaced is not within 10 lbs. (13 Nm) of the specified load (without dampers).
Inspect rocker arm studs for wear or damage. Rocker arm studs that have damaged threads or are loose in cylinder heads should be replaced with new studs available in 0.003 in. (0.0762mm) and 0.013 in. (0.3302mm) oversize. Studs may be installed after reaming the holes as follows:
- Remove old stud by placing Tool J-5802-1 over the stud, installing nut and flat washer and removing stud by turning nut.
- Ream hole for oversize stud using Tool J-5715 for 0.003 in. (0.0762mm) oversize or Tool J--6036 for 0.013 in. (0.3302mm) oversize. Do not attempt to install an oversize stud without reaming stud hole.
- Coat press-fit area of stud with hypoid axle lubricant. Install new stud, using Tool J-6880 as a guide. Gauge should bottom on head.
- Valves with oversize stems are available (see specifications). To ream the valve guide bores for oversize valves use Tool Set J-5830.
- Reconditioning the valve seats is very important, because the seating of the valves must be perfect for the engine to deliver the power and performance built into it.
- Another important factor is the cooling of the valve heads. Good contact between each valve and its seat in the head is essential to insure that the heat in the valve head will be properly carried away.
Several different types of equipment are available for reseating valve seats. The recommendations from the manufacturer of the equipment being used should be carefully followed to attain proper results. It is important that valve seat concentricity be measured. Valve seats should be concentric to within 0.002 in. (0.0508mm) total indicator reading.