Wear Guidelines for Compact Track Loaders {4180} Caterpillar

Compact Track Loader

239D (S/N: CD41-UP; BL91-UP; T9S1-UP)

249D (S/N: AH91-UP; D9E1-UP; GWR1-UP)

259D (S/N: LW51-UP; FTK1-UP; GTK1-UP; FTL1-UP)

279C (S/N: MBT1-UP)

279C2 (S/N: KWB1-UP)

279D (S/N: TP51-UP; GTL1-UP; PPT1-UP; RCX1-UP)

289C (S/N: JMP1-UP)

289C2 (S/N: RTD1-UP)

289D (S/N: WE51-UP; WCT1-UP; TAW1-UP; A9Z1-UP)

299C (S/N: JSP1-UP)

299D (S/N: GTC1-UP; HCL1-UP)

299D XHP (S/N: NLC1-UP; JST1-UP)

299D2 (S/N: FD21-UP)

299D2 XHP (S/N: DX21-UP)

Introduction

This Special Instruction provides the wear guidelines for Compact Track Loader tracks and components. Use the wear guidelines to evaluate when a Compact Track Loader component has reached the maximum wear life or when the component should be replaced.

Note: Do not use wear guidelines to determine warranty or assign failures.

Wear Guidelines

Triple Flange Idler Wall Thickness

Illustration 1	g06099056
Triple flange idler (A) Wall thickness

Measure the triple flange idler wall thickness (A) and compare with the wear guidelines in Table 2.

Dual Flange Idler Wall Thickness

Illustration 2	g06099247
Dual flange idler (B) Wall thickness

Measure the dual flange idler wall thickness (B) and compare with the wear guidelines in Table 3.

Roller Wall Thickness

Illustration 3	g06099270
Roller (C) Wall thickness

Measure the roller wall thickness (C) and compare with the wear guidelines in Table 4.

Track Tread Wear

This measurement will outline tread wear performance. Measurement should be taken from the topmost portion of grouser to lowest level on top surface of track. Underfoot conditions and operating techniques will impact this wear.

Illustration 4	g06099291
Track tread

Illustration 5	g06177220

Measure the depth of the track tread and compare with the wear guidelines in Table 5. If the tread depth is less than 8.0 mm (0.31 inch), schedule a replacement.

Track Forging Wear

This measurement will indicate wear between sprocket and track interface. Underfoot conditions, operating techniques, and maintaining proper track tension can impact this area for wear.

Illustration 6	g06099304
Track forging (D) Track forging width

Illustration 7	g06177251

Measure the track forging width (D) and compare with the wear guidelines in Table 6. If the tread forging width is less than 34.0 mm (1.34 inch), schedule a replacement.

Sprocket Wear

The compact track loader drive sprockets transfer horsepower and torque from the drivetrain to the track. The sprocket will wear naturally against the steel embeds of the track. When replacing the track, the sprocket should be evaluated for wear. The sprocket may need to be replaced at this time to maximize the life of the replacement track. In some cases, where minimal teeth wear has occurred, the sprocket may be rotated and reused for lower owning and operating costs. Underfoot conditions, operation techniques, and maintaining proper track tension can impact this area for wear. If the average three tooth measurement is 178.0 mm (7.0 inch), change the sprocket to the opposite side. If the average three tooth measurement is 165.0 mm (6.5 inch), replacement is needed.

Illustration 8	g06099437
Sprocket (E) Three tooth width (F) Three tooth width (G) Three tooth width

Measure the sprocket three tooth width (E), (F), and (G) and compare with the wear guidelines in Table 7. If the sprocket three tooth width is 178.0 mm (7.0 inch), then swap. If the sprocket three tooth width is 165.0 mm (6.5 inch), schedule a replacement.

Track Tread Wear

As described previously, each undercarriage side is assembled to two independent torsion axles by sliding onto a shaft protruding out of each axle, Each undercarriage side utilizes grease lubricated, serviceable sleeve bearings mounted on the track roller frames. Special geometry hardened washers are slid over the axle shafts prior to assembling the undercarriage sides to create a wear surface between the axle and track roller frame. In addition, hardened washers are bolted to the outer face of each torsion axle to retain each undercarriage side onto the torsion axles. As the parts are installed onto the axles, a nominal gap of up to 6 mm (0.24 inch) occurs between the undercarriage and end cap.

Illustration 9	g06176896

During machine operation, the undercarriages will slide along the torsion axles and the torsion axles will rotate, causing the outer and inner washer, torsion axles, and track roller frame axle housings and washers to wear. If this wear becomes too great, the installation gap will increase between these parts and allow for excessive thrust loading onto the wear surfaces. Periodic review of these areas and following a lubrication schedule can help to limit excessive component damage over time. Shimming options are available if wear rates become excessive. Refer to Illustration 9 for the installation procedure.

Undercarriage practices and machine operation techniques (counter-rotations) can impact this wear.

Shims are available to reduce the gap between the shaft tube and retaining washer. Contact your dealer for appropriate kit or part number. Use the procedure below to measure the gap and determine the proper shimming method.

1. Raise the machine off the ground.

2. Push undercarriage to the inside portion of the axle so the maximum gap is seen between retaining cap and axle.

3. Measure this gap at both front and rear axles.

4. If gap is greater than 6 mm (0.24 inch) on an axle, contact your dealer for appropriate shim kit/part number.

5. Install shims to achieve equal gap measurement on both front and rear axles and such that gapping is less than 4 mm (0.16 inch) on each axle, but at least 1 mm (0.04 inch).

   Joints with no gap may cause bolted end caps to be pre-loaded and fail prematurely.

Torsion Axle End Cap

The compact track loader roller frames are the support structures that house all the working components of the undercarriage. There are two parts of the track roller frame:

• The rear frame which houses the rear idler, sprocket, motor, and recoil cylinder

• The front frame which houses the front idler and roller.

The front frame slides in and out of the rear frame and is connected by the recoil cylinder to maintain correct track tension during machine operation. Due to the sliding motion of the front track and roller frame, the outer surfaces of the front frame structure can wear over time and the gap between the two frames will grow. Correct track tension, maintenance practices, and underfoot conditions can play a role in the rate of wear between the front and rear track roller frames. If the gap becomes too large, wear will increase at a much faster pace and replacement of the front frame may be required. Periodic review of this clearance is necessary with wear rates listed in Table 8. Shim strips are available as a permanent, welded solution to maintain a proper clearance between the two frames. Consult your dealer for this kitted solution.

Illustration 10	g06176878
(A) Rear Frame (B) Front Frame (D) Gap Measurement

Underfoot conditions and machine operation techniques can impact this wear. The gap measurement is illustrated as (D) in Illustration 10.

Checking for Track Wear

Caterpillar recommends checking the torque on the track bolts for the link assembly on the same schedule as the checks for track tension. The track assembly wear charts and recommended replacement lift are as follows.

Note: Maximum wear for parts is 100 percent when working normal impact terrain.

Illustration 11	g03736859
(H) Track shoe measurement

Illustration 12	g03023457
(J) Track link height measurement

Illustration 13	g03023398
(K) Forward drive side wear (L) Radial wear (M) Reverse drive side wear (N) Track bushing wear measurement

Illustration 14	g03023422
(P) Track idler wear measurement

Illustration 15	g03737023
(R) Track carrier roller measurement

Illustration 16	g03023558
(S) Track bottom roller wear measurement