2008/07/07 Caterpillar

Excavator:

320C (S/N: MAB1-UP; AMC1-UP)

320D (S/N: DHK1-UP)

322C (S/N: DAA1-UP; KCF1-UP; BPH1-UP; M2H1-UP; BKJ1-UP; HEK1-UP; BYL1-UP; CAM1-UP; C3R1-UP; LAR1-UP; SLX1-UP; CBY1-UP)

Description of Change: An improved link design is available for certain thumbs. Links were cracking around the welded joint or breaking the retaining bolt for the link pin at low hours during the operation of the thumb.

Adaptable To: The new links have been released for production. Enhanced installation instructions have been developed in order to help ensure proper installation of the thumb.

The thumbs share the same serial number prefix. Use table 1 in order to determine if your thumb is affected.

Table 1

Your thumb may be affected if the serial number is below the effective serial number.
Thumb Model	Thumb Pt. No.	The Change is Effective With The Following Serial Numbers:
320C Pin On	264-0499	S/N:7JW11841-UP
322C Pin On	264-0501	S/N:7JW06500-UP
320C Hydraulic Pin Grabber	264-0500	S/N:7JW11872-UP
322C Hydraulic Pin Grabber	264-0502	S/N:7JW04733-UP
320D Pin On	299-5396	S/N:7JW10268-UP
320D Hydraulic Pin Grabber	299-5397	S/N:7JW10274-UP

Replace the broken links with the improved parts as listed below. Add thumb stop (AA) if the stop is not currently installed. Refer to illustrations 1 and 2. Refer to table 2 in order to determine the correct parts for C series machines. Refer to table 3 in order to determine the correct parts for D series machines.

Note: Installation and positioning of the thumb stop is critical and will lead to reduced link life if not properly installed. Ensure the stop engages the thumb frame when the machine stick is extended in a horizontal position and the weight of the thumb is pulling it away from the stick. If stop (AA) does not contact the thumb frame with the stick in this position, reposition the stop.Consult the thumb installation Special Instruction, GEBI0258 for detailed instructions. Use this website in order to download a copy of the manual.

http://64.22.192.186

Illustration 1	g01509015
Typical example with old link (A) Old Link (RH) (B) Old LInk (LH) (E) Spacers (F) Pin (AA) Stop

Illustration 2	g01514032
Typical example with new link (C) New link (RH) (D) New link (LH) (G) Pin (AA) Stop

Table 2

Machine / Style	Thumb Pt. No.	Old Link Pt. No.	Improved Link Pt. No.	Removal of Parts	Additional Parts
320C / Pin On	264-0499	247-5461 (A)	319-0399 (C)	157-7273 (1) (E)	306-4186 (3) (AA)
		247-5462 (B)	319-0400 (D)
322C / Pin On	264-0501	247-5461 (A)	319-0401 (C)	231-8989 (2) (F)	319-0741 (G) 306-4186 (3) (AA)
		247-5462 (B)	319-0402 (D)
320C / Hydraulic Pin Grabber	264-0500	243-1662 (A)	319-8948 (C)	157-7273 (1) (E)	306-4186 (3) (AA)
		243-1727 (B)	319-8947 (D)
322C / Hydraulic Pin Grabber	264-0502	243-1662 (A)	319-8950 (C)	231-8989 (2) (F)	319-0741 (G) 306-4186 (3) (AA)
		243-1727 (B)	319-8949 (D)

( 1 )	Removal of the two 157-7373 Spacers is required when installing the improved links
( 3 )	Required if not already installed
( 2 )	Remove the old 231-8989 Pin and replace with the new, longer 319-0741 Pin .

Table 3

Machine / Style	Thumb Pt. No.	Old Link Pt. No.	Improved Link Pt. No.	Removal of Parts	Additional Parts
320D / Pin On	299-5396	299-6997 (A)	319-0403 (C)	157-7273 (1) (E)	306-4186 Stop (AA)
		299-6998 (B)	319-0404 (D)
320D / Hydraulic Pin Grabber	299-5397	299-6757 (A)	319-8951 (C)	157-7273 (1) (E)	306-4186 Stop (AA)
		299-6758 (B)	319-8952 (D)

( 1 )

Removal of the two 157-7373 Spacers is required when installing the improved links