NMWR-9-2815-220 Overhaul Manual for M60 M88 Engine AVDS-1790-2CA, AVDS-1790-2DA, AVDS-1790-2DR Download
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NMWR 9-2815-220 CAMSHAFT AND DRIVE ASSEMBLIES OVERHAUL—Continued 0016 00 REPAIR 1. Refer to WP 0005 00 for general repair instructions. 2. Camshaft repair. Repair damaged threads in the gear hub with a used tap. Remove slight scuffing or scoring from camshaft lobes and bearings with a fine oil stone and polish with crocus cloth dipped in cleaning compound solvent. 3. Camshaft straightening. (a) Checking camshaft bearing journal runout. Camshafts may be straightened if the runout of any one camshaft bearing surface (journal), when using a dial indicator, does not exceed 0.060in. (1.524mm) total indicator reading (TIR) when supported at the two adjacent bearing journals. Camshafts that exceed 0.0600 in. (1.5240 mm) runout between any two journals must be discarded. Maximum journal runout of straightened camshafts is 0.0020 in. (0.0508 mm) (TIR) when supported at the two adjacent journals. After straightening a camshaft, the maximum acceptable runout of the center bearing journal, when supported at the end journals, is 0.0150 in. (0.3810 mm) (TIR). Check camshaft bearing journal runout as follows: (1) Support the camshaft at the two end journals in V blocks on a surface plate or other available centering device, such as a machine lathe. (2) Position a dial indicator at the center bearing journal and obtain a zero reading on the dial. (3) Rotate the camshaft and determine the maximum travel of the dial indicator needle. If travel (TIR) exceeds 0.0150 in. (0.3810 mm), the camshaft must be straightened. (4) Repeat steps (2) and (3) above for each bearing journal and mark position and dimension of maximum dial indicator reading at each journal. (5) Check runout of each camshaft bearing journal. Support the camshaft in V blocks at the adjacent journals, and using a dial indicator, check and record journal runout (TIR) dimensions. If runout exceeds 0.0020 in. (0.0508 mm), camshaft must be straightened. (b) Camshaft straightening procedure. (1) Install camshaft on truing device (Figure 3) with bearing journal having the maximum runout (TIR) positioned under the pressing spindle. (The camshaft journals must be resting on the support blocks when rotating the camshaft to determine the runout). Set dial on indicator to zero and rotate camshaft to determine location of runout (TIR) and record reading. 0016 00-6 Change 1