Bedknife Adjuster Spring; Bedknife Adjuster Tension; Grinding Bedknife; Belt - Jacobsen 67991 Maintenance Manual

3.7

BEDKNIFE ADJUSTER SPRING ______________________________________________

For proper operation, bedknife adjuster spring should be
compressed to a dimension of 1-7/16 - 1-1/2 in. (36.5-38
mm).
To adjust spring compression, loosen or tighten nut (R) to
obtain a distance of 1-7/16 - 1-1/2 in. (36.5-38 mm).
After adjusting spring, check reel to bedknife adjustment.
3.8

BEDKNIFE ADJUSTER TENSION _____________________________________________

NOTICE
Overtightening slotted nut (S) will make bedknife
adjuster rod (T) difficult to adjust.
Remove cotter pin (U) and fully loosen, then tighten
slotted nut (S) to remove clearance (no end play)
between components. Continue to tighten nut until next
slot in nut aligns with hole in bedknife adjuster rod (T).
Install new cotter pin.
Check torque required to rotate adjuster rod (T).
Maximum torque should be 24 in. lb. (2 ft. lb.) (2.7 Nm).
3.9

GRINDING BEDKNIFE ______________________________________________________

Bedknife can be lowered out of the reel for grinding
without completly removing the bedknife assembly.
1. Remove cotter pin (U), slotted nut (S), bellville
washer (V), shim washer (W-If required), and half
trunnion (X). See Figure 3H

3.10 BELT ____________________________________________________________________

Inspect and adjust new belt after first ten hours of operation.
Adjust every 100 hours thereafter.
Adjust alternator pulley so belt deflects 1/4 to 5/16 in. (6 to 8
mm) with a 20 lb. push at midpoint between pulleys. See
engine manual.
If tension is incorrect, loosen alternator mounting bolts (B)
and adjust alternator until proper belt tension is achieved.
R
After adjusting nut, check reel to bedknife adjustment.
T
1. Press down on adjuster end of rod (T) to rotate other
end of the adjuster out of the bedknife finger.
2. Rotate bedknife backing to access the reel and
bedknife for grinding.
3. After grinding, assemble bedknife using reverse
order of removal. Check adjustment of bedknife
adjuster tension (Section 3.8), and reel to bedknife
adjustment (Section 3.3).
ADJUSTMENTS
1-7/16 to 1-1/2 in.
(36.5 to 38 mm)
Figure 3G
X
W
V
U
S
Figure 3H
B
1/4 to 5/16 in.
(6 to 8 mm)
Figure 3I
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