Company News
Can You Mix Old & New Track Chains? Risks You Should Know
2026-08-19
Many equipment owners try to cut repair costs by installing one brand‑new track chain while keeping the worn old chain on the opposite side. This cost‑saving shortcut is common in field maintenance, yet few operators fully understand the long‑term damage it brings to the whole undercarriage system.
Even if both track chains fit physically onto the machine, mismatched wear levels will create persistent mechanical problems and raise total operating costs.
Key risks of mixing new and used track chains
1. Unequal travel speed and machine pulling to one side
Old track links have worn pins and bushings, creating longer effective chain pitch compared with a brand‑new chain. When travelling, the two sides move at slightly different speeds. The excavator will constantly pull toward one direction. Operators have to continuously correct steering, which increases driver fatigue. Uneven travel also accelerates wear on sprockets, idlers and Rollers.
2. Severe abnormal wear across the whole undercarriage
A new chain has original pitch dimensions, while a worn old chain has stretched pitch. When running toGether on the same machine: ‑ New chain will bite deeply into sprocket teeth; ‑ Worn old chain will skip and ride high on sprocket teeth. This inconsistent meshing generates heavy shock loads. Sprockets, idlers, bottom rollers and carrier rollers will suffer premature damage. You may need to replace these components long before their expected service hours.
3. Higher risk of track de‑tracking
The difference in chain pitch changes track tension balance between left and right sides. One track may stay too tight while the other runs loose. During turning, slope operation or crossing rough ground, the looser side is much more likely to jump off, causing costly site downtime.
4. Extra stress on final drives
Two final drives are forced to output different torque to compensate for mismatched chain pitch. Continuous torsional stress acts on gears and bearings inside final drive units. In severe cases, it leads to overheating, oil leakage and early final‑drive failure. Repairing final drives involves very high parts and labour expenses.
Are there any acceptable exceptions?
In emergency breakdown situations on‑site, fitting one new chain can serve as a short‑term temporary fix to move the machine off a dangerous work zone.
Important: This solution is only for relocation, not for normal digging, loading or long‑distance travelling. Plan full undercarriage replacement as soon as site conditions permit.
Practical guidance for fleet managers
- Best practice: Replace both left and right track chains at the same time. It delivers the longest overall undercarriage life and lowest total cost of ownership.
- If rollers, sprockets or idlers show heavy wear when you install new chains, replace these worn components together. Fitting new chains onto heavily worn wheels will still cause fast chain deterioration.
- Keep records of working hours for each undercarriage group, arrange overhaul plans in advance instead of waiting for sudden breakdown.
Closing
Mixing new and worn track chains may save immediate material cost, but it creates cascading damage across sprockets, rollers and final drives. The unexpected repair bills and unplanned downtime will far exceed the money saved. For long‑term fleet profitability, matched undercarriage components are always the smarter choice.