Specifications

© 2002 Alamo Group Inc.
Parts Section -151
Triumph Sickle Bar (Archive Book) 10/02
SERVICE INSTRUCTIONS
REMOVING THE KNIFE:
CAUTION! HANDLE WITH CARE. WEAR GLOVES. GRASP THE KNIFE HEAD AND KNIFE BACK.
2500-3500 Models:
Insert a pointed tool into the hole in the pitman fork and rotate it upward and forward. It will snap
over center---pry pitman arm upward off knife head ball. Slide knife out rear of mower. After
installing new knife, snap pitman arm over knife head ball, and using pointed tool, rotate pitman
fork upward and rearward. It will snap over center and lock the pitman arm to the knife head
ball. See Figure #18, as well as Figures on other Pages.
8500 Pitmanless Model:
Loosen knife drive pin clamping screw in the drive arm. Fit a screw driver into the small groove
in the drive pin and pry up until the pin is free. Slide the knife out of the cutterbar. After installing
new knife, push the drive pin down into the knifehead bushing. Tighten the clamping screw to
75 ft. lbs. torque. See Fig. #19 as well as other Figures on other pages
KNIFE REPAIR:
ALWAYS USE A SHARP KNIFE. A dull knife cuts poorly, may plug, and doesn't do a clean job.
Keep the knife straight with the sections firmly riveted to the knife back. When sharpening
theknife,be careful to restore the original shear angle and bevel of 23 degrees. Properly
and improperly ground knife sections are shown in the Figure #20 next page. A knife section
that has been ground several times may have the proper angle and bevel and still be
unserviceable because the hard cutting edge has been ground away and the section is too
short to cut everything encountered. Replace worn or broken knife sections. Triumph knife
sections are heavy duty sections made of special steel and will stay sharp for many more
hours than conventional sections. Shear off the rivets rather than punch them out, as a punch
will enlarge the holes in the knife back. Over a slightly open vise with the sections pointing
down, strike the flat rear edge of the section a sharp blow with a hammer to shear the rivets.
WEAR SAFETY GLASSES anytime you are striking these hardened steel parts. Chips off a
knife section may cause injury or even loss of sight.
KNIFE HEAD:
2500-3500 Models:
When the knife head ball has worn to the point where it is no longer held snugly by the pitman,
the knifehead must be replaced. Follow the same rivet shearing instructions given above.
8500 Pitmanless Model:
If side play is evident between the knife drive pin and the knife head, it will be necessary to
replace the bushing in the knife head. Use a one-inch diameter pipe or shaft and drive the plug
out the bottom of the knife head. Be careful when removing plug not to deform it. Next press
out the worn bushing; Replace plug and press in new bushing. Examine the knife drive pin at
this time and replace it if it is loose in the new Bushing.
Always use sharp ledger plates. The ledger plates provide one half of the shearing action.
Worn and dull ledgers should be replaced. To cut cleanly and efficiently, sharp ledgers are as
important as a sharp knife.