Item 7 - Tachometer Drive; Item 8 - Drive Belts - Detroit Diesel 50 Series Operator's Manual

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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.
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
Single Belt
80 – 100 lbs (356 – 445 N)
Belt
Two 1/2–in. V-Groove
2–Groove PowerBand
12–Rib Poly-V (50 DN Alternator)
Table 18 Drive Belt Tensioning
72
6SE550 0401 Copyright © 2004 DETROIT DIESEL CORPORATION
result in crankshaft breakage. A loose
belt will slip and may cause damage
to accessory components.
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
poly-V belt), or equivalent, when
tensioning drive belts. Tension belts
to the values listed in Table 18.
Fan Drive
2 or 3 Belts
60 – 80 lbs (267 – 356 N)
Alternator Drive
New
125 lbs (556 N)
®
200 lbs (890 N)
350 lbs (1,557 N)
All information subject to change without notice. (Rev. 01/ 04)
® and 12–rib
Used
100 lbs (445 N)
150 lbs (667 N)
250 lbs (1,112 N)