3. Measure thickness of internal-splined clutch plates (2) and (5). Replace-internal splined clutch plate(s) (2) and (5) if thickness is less than 0.090 in. (2.29 mm). 4. Place external-tanged clutch plates (1) on clean, level surface. Measure distance from inside diameter to level surface. Replace external-tanged clutch plate(s) (1) if distance is more than 0.010 in. (0.25 mm). 5. Inspect springs (8) for broken coils, wear, and discoloration due to overheating. Replace spring(s) (8) if broken, worn, or discolored. Springs (8) should be solid yellow or solid orange with yellow stripe. Using spring tester, check spring load (refer to table 2, First Clutch Spring Wear Limits, for proper measurement). Replace spring(s) (8) if not within limits. 6. Inspect snapring (3), snapring retainer (7), and piston (9) for scratches, scores, burrs, and wear. Remove minor scratches and burrs on travel and seal surfaces with crocus cloth. Replace if damaged. 7. Inspect ring gear (6) teeth for burrs. Remove burrs with crocus cloth. Replace ring gear (6) if damaged. IDENTIFICATION THICKNESS NO. INCHES MILLIMETERS 4 0.683 - 0.693 17.35 - 17.60 5 0.647 - 0.657 16.43 - 16.69 6 0.611 - 0.621 15.52 - 15.77 Table 1. First Clutch Backplate Thickness. SPRING FREE COMPRESSED LOAD COLOR LENGTH LENGTH LIMIT Solid Yellow 1.53 in. (38.9 mm) 1.01 in. (25.7 mm) Solid Orange 1.28 in. (32.5 mm) 0.95 in. (24.1 mm) W/Yellow Stripe Table 2. First Clutch Spring Wear Limits. 3.59-4.81 lb (16.0-21.4 N) 13.60-16.40 lb (60.5-73.0 N) CLEANING AND INSPECTION NOTE The first clutch backplate is a selective part marked by number 4, 5, or 6. Identify and record backplate number if inspection indicates need for replacement. WARNING Volatile mineral spirits burn easily and fumes can explode. Do not smoke or allow flames nearby when using volatile mineral spirits. Failure to do so may cause serious injury or death to personnel. 1. All metallic parts should be cleaned thoroughly with mineral spirits and dried with a lint-free rag. 2. Inspect backplate (4) for scratches, scores, burrs, and wear. Remove minor scratches and burrs with crocus cloth. Measure thickness of backplate (4) (refer to table 1, First Clutch Backplate Thickness, for proper measurement). Replace backplate (4) if damaged or worn less than minimum thickness. 0381 00-6 TM 9-2320-386-24-1-2 0381 00 FIRST CLUTCH MAINTENANCE (Contd)