TM 10-4320-315-24
4-6.
MAINTENANCE OF PISTONS - (Cont)
(5)
Measure groove width of second and third piston ring grooves. Correct clearances are:
Second groove = 0.102-0.103 in. (5.90-2.61 mm).
Third groove = 0.198-0.199 (5.030-5.050 mm).
Figure 4-8. Piston
(6)
Insert ring into cylinder. Use piston to push ring down to a point approximately 1 in. (25.4 mm) from
top of cylinder. Measure and record ring end gap. Remove ring.
(7)
Repeat step (6) until all rings have been checked.
NOTE
If ring gaps do not meet specifications, piston rings are defective.
(8)
Correct ring end gap. Clearances are:
Trapezoidal compression ring = 0.012-0.018 in. (0.30-0.45 mm).
Tapered compression rings = 0.008-0.018 in. (0.20-0.45 mm).
Scraper ring = 0.050-0.016 in. (0.250-0.40 mm).
4-13