MAINTENANCE Item 7 – Tachometer Drive A typical tachometer drive take-off location is the camshaft drive gear access cover on the front of the gear case cover. Lubricate the tachometer drive (if so equipped) every 150 hours or 15,000 miles (24,000 km) with an all-purpose grease. At temperatures above –1° C (+30° F) use a No. 2 grade grease. Use a No. 1 grade grease below this temperature. PERSONAL INJURY To avoid injury from rotating belts and fans, do not remove and discard safety guards. Use a belt tension gage, such as Kent-Moore® tool J 23586–B (V-belt), J 23600–B (poly-V belt), J 41251 (PowerBand® and 12–rib poly-V belt), or equivalent, when tensioning drive belts.
Tension belts to the values listed in Table 13. Item 8 Drive Belts Belts should be neither too tight nor too loose. Belts that are too tight impose extra loads on the crankshaft, fan and/or alternator bearings, shortening both belt and bearing life. Excessively overtightened belts can result in crankshaft breakage. A loose belt will slip and may cause damage to accessory components. V-Belts New standard V-belts will stretch after the first few hours of operation. Tighten V-belts as listed in Table 13. Table 13 Drive Belt Tensioning 64 All information subject to change without notice.
DDC-SVC-MAN-0039 Copyright © 2009 DETROIT DIESEL CORPORATION Fan Drive Single Belt 2 or 3 Belts 80 – 100 lbs (356 – 445 N) 60 – 80 lbs (267 – 356 N) Alternator Drive Belt New Used Two 1/2–in. V-Groove 125 lbs (556 N) 100 lbs (445 N) 2–Groove PowerBand® 200 lbs (890 N) 150 lbs (667 N) 12–Rib Poly-V (50 DN Alternator) 350 lbs (1,557 N) 250 lbs (1,112 N)