TM-9-2815-237-34 HMMWV Engine Direct Support & General Support Maintenance Manual Download
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TM 9-2815-237-34 2-41. ENGINE ASSEMBLY FROM SUBASSEMBLIES (Cont’d) NOTE ● During assembly operations, it is important to closely inspect each unit to make sure nothing has been overlooked during inspection and repair. Plugs should be checked for tightness, parts kept clean, openings covered, and machined surfaces protected. Application of lubricant should be performed from covered containers. ● Work area should be clean, well-ventilated, and free of blowing dirt and dust. ● In some cases, flanged head fasteners may be present instead of standard fasteners and washers. In all cases, washers should be used when replacing a flanged head fastener with a standard fastener. ● For general assembly instructions, refer to para. 2-12. ● Assembly procedures for pre-1990, 1990 and above 6.2L and 6.5L engines are basically the same. Any differences in procedures are noted. Some replacement parts are different. Refer to para. 1-10 to determine engine model before ordering replacement parts. a. Crankshaft and Main Bearings NOTE ● Measure outside diameter of crankshaft main bearing journals to determine what thickness main bearings to install. ● Main bearings are of the precision insert type and do not utilize shims for adjustment. If clearances are found to be excessive, a new bearing, both upper and lower halves, will be required. Service bearings are available in standard size and undersize. ● Selective fitting of both rod and main bearing inserts is necessary in production in order to obtain close tolerances. For this reason you may find one-half of a standard insert with one half of a 0.001 in. (0.025 mm) undersize insert, which will decrease the clearance 0.0005 in. (0.013 mm) from using a full standard bearing. 1. Remove all capscrews (1) and (2) and bearing caps (3) and install upper halves of main bearings (7) in cylinder block (6). 2. Install lower halves of main bearings (4) in bearing caps (3). Crankshaft must be supported during removal and installation. Failure to support crankshaft may cause injury to personnel or damage to equipment. 3. Install crankshaft (8) in cylinder block (6). NOTE The gaging plastic shall be positioned the full width of the bearing and centered on the bearing journal when the bearing cap is installed. 4. Position gauging plastic on bearing journal (5) the full width of the bearing (4) and parallel to the center line of the crankshaft (8). 2-154