Usage:
CONFIDENTIAL TIBU4362-00
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TECHNICAL INFORMATION BULLETIN |
OCTOBER 06, 2004 |
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EXCAVATORS |
320C (FBA, GHA, MAA, BCB, MAB, AMC1-1326, BDC, FBC, CCD, BEF, DBG, AKH, BCN, BPR, RAW), 320C S (BBL, EGL), 320C U (APA, FBB1-683, MAC1-287, CLM), |
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Component Code(s) 4157, 4158 |
SUBJECT: THE NUT FOR THE SPRING IN THE TRACK ADJUSTER AND RECOIL
GROUP MAY BECOME LOOSE ON CERTAIN EXCAVATORS
PROBLEM:
The ends of the spring in the track adjuster and recoil group may not be machined square to the axis of travel for the spring. When the spring in the adjuster is compressed and expanded, the spring would produce an uneven action. The uneven action of the spring created a rotary force that would loosen the nut. The nut would loosen, the strip would deform, and the bolts would shear.
SOLUTION:
If the 3E-8024 Hex Nut in the track adjuster and recoil group becomes loose, the two 7X-2536 Bolts shear, and the 122-5253 Strip deforms; replace the former spring in the track adjuster and recoil group with a new 145-3036 Spring. The locations of the components are shown in Illustration 1. Make sure that you reference the Disassembly and Assembly Manual that is appropriate for your machine before replacing the spring.
The spring of the recoil spring assembly is com-
pressed under several tons of force.
Do not attempt to compress or release the tension
of the spring with the nut on the end of the retain-
ing rod.
Damaged threads on the retaining rod or nut can
cause the assembly to come apart with force, re-
sulting in injury or death.
Illustration 1. Typical Track Adjuster And Recoil Group
(A) 3E-8024 Hex Nut
(B) 122-5253 Strip
(C) 7X-2536 Bolt
(D) 145-3036 Spring
The phantom lines in Illustration 1 show the movement of the spring when the ends of the spring are machined incorrectly. The uneven spring movement creates the rotary force that loosens the nut.
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