HOSE AS 4921170 - Caterpillar

TECHNICAL INFORMATION BULLETIN August 27, 2003
PRODUCT FAMILY(S) 988G (S/N: 2TW1-Up)
Component Code(s) 6107, 7620-IISUBJECT: Lift Arms are Jerky at Full Lift with New Software
PROBLEM:
New implement software, 219-6299, has been installed on all 988G s/n 2TW machines with PI30280, April 8, 2003, Service Letter. One of the improvements with this software is the reduction of FRAC - Full Rack Angle Control that tips the bucket forward as the lift arms pass the level position to the top. The FRAC in the new software operates only near full lift. This allows faster lift cycle times.
Some customers have noticed jerkiness of the lift arms near the top, after the new implement software was installed. This may occur when the lift kickouts are set very near to the top, where the FRAC and lift snubbing is operating.
SOLUTION:
The jerkiness can be removed by setting the lift kickout lower, approximately 100 mm of rod stroke below full lift. The operator can lift to full height with the lever when needed. Later 988G's (s/n BNH) do not have this as the lift snubbing has priority over the kickouts. A software change for the 2TW machines is being investigated.
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