How to Replace Caterpillar Track Parts?

Replacing Caterpillar track parts is one procedure with two versions, and knowing which one you are doing is most of the job. On a rubber-tracked machine the work is a belt and its steel: release the tension, walk the belt off, fit the new one, re-tension it. On a steel-tracked machine the same sequence applies to a chain, but the components around it - rollers, idler, sprocket, shoes - come apart individually and are usually judged as a set. Either way the two steps that decide whether the job succeeds are the inspection before anything is ordered, and the safety of releasing the tensioner.

Last updated: October 6, 2026

This guide covers what the parts are, how to inspect them, when each one is due, the replacement sequence for a belt and for a chain, the tools and the one safety rule that matters most, and the fitment checks that stop the work being repeated. The full range is in the rubber tracks guide for belts and in the undercarriage parts guide for the steel.

The parts, and which ones come due together

The track - a rubber belt on compact machines, a steel chain with shoes on larger ones - is the part that touches the ground and the last one to fail. Track rollers carry the machine's weight on the lower run and are usually the first component to wear. The front idler sets the chain's line and carries the tensioning load, and is the part most often blamed for a problem that belongs to the tensioner. The drive sprocket engages the links and hook-wears as it runs. The tensioner - a grease cylinder behind the idler - sets how the whole system runs.

Inspection decides the order rather than the parts list. With the machine supported and the track slack, turn each roller by hand, look for weeping seals and play on shafts, check the sprocket teeth for hooks, look at the idler face for a groove, and read the belt for cracks, exposed cord and lost lug height. What that produces is a list of what is actually due, which is the only list worth ordering from.

When each part is due

The belt or chain is finished when the lugs have rounded off, cracks appear at the lug base or across the belt, a cord strand shows at a cut, or the belt stops holding tension between adjustments. Rollers are due when the running surface has grooved, when the roller will not turn by hand, when it rocks on its shaft, or when the seal weeps - a sealed roller cannot be re-greased, so a weep is the end. The idler follows the same logic, plus play in the yoke. The sprocket is due when the teeth are hooked, when one side wears faster than the other, or when the chain starts climbing the teeth under load.

The habit worth building is recording the hours and the ground each time a set goes on. Abrasive ground, constant turning and a mis-set tension all shorten life, so a comparison against your own history is more useful than any published figure.

Preparation and tools

Park on firm, level ground, lower the attachment, isolate the machine and chock it. Support the machine on stands rather than on the bucket, because the undercarriage has to be unloaded for the tension to come off safely. Clean the undercarriage - packed material holds the track off its seat and hides the wear you are looking for.

For a rubber belt: a high-pressure grease gun for the tensioner, a bar for walking the belt off, a torque wrench for any hardware you disturb, gloves and eye protection. For steel: the same list plus the tooling for the shoe bolts and the pins or masters on the chain. Have the fasteners ready before you start - on an undercarriage that has been in the ground for years, bolts and pins are single-use items more often than not, which is the same rule that applies to track shoe hardware in OEM versus aftermarket replacement parts.

The replacement sequence

Release the tension. Open the tensioner's relief valve and let the cylinder return. This is the step to slow down for: the grease leaves the valve under pressure and can be hot, so keep your face and hands out of the line of the outlet and catch the grease rather than letting it spray across the site.

Take the track off. On a rubber machine, walk the belt off the sprocket and idler with the bar, lifting the edge over the flange rather than levering against the face. On a steel machine, break the chain at the master link and pull it clear, or split it as the machine's design allows.

Inspect and replace the steel. With the track off, clean the frame out and check every roller, the idler and the sprocket. Replace what is due now, and clean the mounting faces - a face with grit or rust on it seats the replacement out of line.

Fit the new track. Lay a rubber belt over the sprocket and idler with the tread facing out and the lugs engaged, then work it onto the frame, confirming it is seated on every roller before tensioning. For a chain, assemble with the correct master link and pins, torque to specification, and fit the shoes with new hardware.

Re-tension. Pump the cylinder slowly, in small increments, until the belt or chain reaches the figure in the machine's manual, measured at the point the manual names. Over-tensioning is the more expensive error of the two. On machines where the adjustment is done at a bolt rather than a cylinder - the arrangement covered in track tension bolt sizing - the same principle applies: set it to the specification, not to feel.

After the job

Run the machine briefly, then re-check the tension: a new belt or chain takes its initial stretch in the first hours, and the re-check is what stops a setting that felt right from running loose. Listen for a rhythmic slap that would indicate a link not seated, and look for the belt tracking evenly on every roller.

Two records make the next replacement cheaper: the part numbers fitted, with the hours at which they went on, and the tension figure the machine is set to. Together they replace a supplier's claim with your own history - and they are the first thing anyone will ask for if a part fails early.

FAQs

Can I replace Caterpillar track parts myself?

Yes, if the machine is properly supported and the tensioner is released safely. The sequence is mechanical: release tension, remove the track, inspect and replace the steel, fit the new track, re-tension to the manual's figure.

What causes a track to come off?

Usually tension: a belt or chain run too loose climbs the sprocket or walks off in a turn. Worn rollers, a grooved idler or a hooked sprocket make it worse, and an alignment problem will keep doing it until it is corrected.

Should I replace the sprocket when I replace the track?

Where both are worn, yes. A new track on a hooked sprocket wears its bushings from the inside out, and a new sprocket under a stretched chain wears quickly - the two are usually cheaper as a pair.

How often should track tension be adjusted?

Check it visually in the daily walk-round and measure it at the service interval, plus after any undercarriage work and after the first few hours on a new track. Use the machine's specified figure, not a rule of thumb.

Can steel tracks be changed to rubber?

On some machines yes, and on others the undercarriage and chassis are not designed for it. It is a specification question for the model and serial number rather than a straight swap, so confirm it with the machine's documentation first.