The Purpose of the Vent Hole on the Final Drive for Certain H, K, M, M Series 2, and M Series 3 Motor Graders {4050} Caterpillar

Motor Grader

120H (S/N: CAF1-UP; 4MK1-UP; 6NM1-UP; 6TM1-UP; 9YR1-UP; ALZ1-UP)

120K (S/N: SZN1-UP; JAP1-UP)

120M (S/N: R9A1-UP; B9C1-UP; R9C1-UP; B9N1-UP; B9W1-UP; D9W1-UP)

120M Series 2 (S/N: M9C1-UP; M9H1-UP; R9N1-UP; R9W1-UP)

12H (S/N: XZJ1-UP; CBK1-UP; 4XM1-UP; 5ZM1-UP; 8MN1-UP; 2LR1-UP; 4ER1-UP; 2GS1-UP; AMZ1-UP)

12K (S/N: JJA1-UP; SZP1-UP)

12M (S/N: R9B1-UP; B9F1-UP; B9R1-UP)

12M Series 3 (S/N: N9B1-UP; N9F1-UP; N9P1-UP; N9R1-UP)

12M Series II (S/N: M9F1-UP; R9R1-UP)

135H (S/N: CBC1-UP; BDJ1-UP; 3YK1-UP; 7MM1-UP; 8WN1-UP; AMX1-UP)

140H (S/N: CCA1-UP; XZH1-UP; 2ZK1-UP; APM1-UP; 5HM1-UP; 8JM1-UP; 8KM1-UP; 3AS1-UP)

140K (S/N: SZL1-UP)

140M (S/N: B9D1-UP; B9G1-UP; D9G1-UP; B9M1-UP)

140M Series 2 (S/N: M9D1-UP; R9G1-UP; M9J1-UP; R9M1-UP)

140M Series 3 (S/N: N9D1-UP; N9G1-UP; N9J1-UP; N9M1-UP)

143H (S/N: 1AL1-UP)

14H (S/N: ASE1-UP; 7WJ1-UP)

14M (S/N: B9J1-UP; R9J1-UP)

14M Series 3 (S/N: E9S1-UP; N9S1-UP)

160G (S/N: 4JD1-UP)

160H (S/N: ASD1-UP; 9EJ1-UP; XZK1-UP; 2FM1-UP; 3GM1-UP; 6WM1-UP; 9JM1-UP; CCP1-UP; 2HS1-UP)

160K (S/N: SZM1-UP; JBP1-UP)

160M (S/N: B9E1-UP; B9L1-UP; B9T1-UP; D9T1-UP)

160M Series 2 (S/N: M9E1-UP; M9K1-UP; R9L1-UP; R9T1-UP)

160M Series 3 (S/N: N9E1-UP; N9K1-UP; N9L1-UP; N9T1-UP)

163H (S/N: 5AK1-UP; ARL1-UP)

16H (S/N: 6ZJ1-UP; ATS1-UP)

16M (S/N: B9H1-UP; R9H1-UP)

16M Series 3 (S/N: E9Y1-UP; N9Y1-UP)

18M Series 3 (S/N: N9A1-UP; E9W1-UP)

24 (S/N: E9Z1-UP; N9Z1-UP)

24H (S/N: 7KK1-UP)

24M (S/N: B931-UP; B9K1-UP)

Service Magazine, SEPD1597, 17, April 2013, "The Purpose of the Vent Hole on the Final Drive for Certain H, K, M, and M Series 2. Motor Graders". Disregard this article. Refer to the information in the following article.

Reference: Refer to your machines Disassembly and Assembly Manual, "Housing (Tandem) - Remove and Install"

Illustration 1	g03367692
(1) vent hole

During service repair orient the vent hole on the final drive group housing towards upward position.

Vent hole (1) on the tandem square has two purposes in the final drive on Motor Graders.

• Cat Advance 3Moly Grease lubricant or Dow Corning Molykote BR-2 Plus grease are used on the wear bands and thrust washers. When setting the end gap of the thrust washers in the final drive, remove vent plug (1). Refer to Illustration 1. A removed plug will allow air to escape during the adjustment process. If air is trapped during the adjustment process, then incorrect setting measurements could be made to the end gap thrust washer setting. Do not use the Loctite moly paste to lubricate the wear bands and thrust washers.

• The vent hole also allows for the adding of oil to the assembly. One cup of 30 weight oil can be added at the vent plug opening. Adding of this oil is recommended if a squeaking noise is coming from the tandem housing during oscillation. As an example, this noise can occur when the oscillation procedure is performed on an uneven grading surface.