Caterpillar — Undercarriage Inspection
Testing & diagnosis
From a Caterpillar service manual covering: Challenger 65, Challenger 70, Challenger 75, Challenger 85, Challenger 95. Check it applies to your exact model before use.
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Before you start
- When replacing midrollers, always replace in sets on the same axle.
- Worn tensioner bushings will damage the tension cylinder and can cause track slippage.
Procedure
- Loosen all front axle spindle bolts and break loose the assembly so shims can be removed.
- Inspect the front idler inside and outside sidewalls for cracking or fatigue.
- Check the rubber condition on the midrollers and replace as required.
- Check the drivewheel rubber condition; replace if groove edges are rounded or groove depth is less than 1/4 inch.
- Check the front tensioner bushings in the frame and at the tensioner rod end.
Tools required
- 15/16 inch combination wrench or 1/2 inch drive impact wrench
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Front idler air pressure 90 psi
- Non-gel filled idler life around 3000-4000 FridayParts $2619.60 h
- Drivewheel groove depth minimum 1/4 inch
Source: Caterpillar service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.