TM 10-3930-653-14&P (10) Measure inner diameter of clutch drum, and replace, if unsatisfactory. Unit: mm(in) Checking Item   Standard Value Service Limit Clutch drum inner 122.00-122.05 diameter (4.803-4.805) -- (11) Using a thickness gauge, measure clearance between back plate and snap ring. If unsatisfactory, replace back plate or clutch disk. Unit: mm(in) Checking Item   Standard Value Service Limit Clearance be- tween back 1.0-1.6 plate and snap 306-25 (0.04-0.063) ring Fig. 4-290. Fig. 4-291. 4 - 162