Track Master Pin: Press-Fit or Slide-In? Split the Chain Safely

Need to take a steel track off or rejoin it, but can’t tell if the master pin will drift out or needs a press? Find the master pin, check whether it is slide-in or press-fit, and release the track tension first.

PartsForMachines has over 5,000 parts in its Under Carriage Hardware range, from press-fit and slide-in master pin kits to track bolts, nuts and adjuster grease nipples for tracked excavators, dozers and other plant.

Press-Fit or Slide-In: Which Master Pin Does My Track Have?

It comes down to the retainer, so check the pin ends. A slide-in master pin is a slip fit held in by a retainer, such as a snap ring or cotter pin. A press-fit master pin is held by its tight fit in the links instead.

Photograph both ends of the joint before you order, because for many models we list both types: the ID09417 press-fit master pin kit and the ID09418 slide-in master pin kit are both for the Case CX210B. If you can’t see a retainer on any pin, check the parts book or send us the photos.

Can I Split the Track With a Sledgehammer, or Do I Need a Press?

A press-fit master pin normally needs a hydraulic press rather than a sledgehammer, both to come out and to go back in. A slide-in pin is kept in by its retainer, so once that is off the pin can be driven or pulled out.

Release the track tension first. If parts of the joint are damaged on the way out, rejoin the chain with a new kit, such as the ID33252 press-fit master pin kit for the Komatsu PC210LC-8.

Track Keeps Going Slack: Is It the Grease Valve or the Adjuster?

It can be either, so find where the grease is escaping: the grease trapped in the adjuster’s cylinder is what holds the track tight. Opening the valve lets grease out, so a valve that wasn’t fully tightened can let the track creep slack.

Wipe the valve, nipple and adjuster clean, work the machine, then look. Fresh grease round the valve or nipple points to a simple fix: retighten the valve or fit a new nipple, such as the ID21009 grease nipple for the Hitachi ZX130. If everything stays dry and the track still slackens, stop topping it up and have the adjuster checked.

Loose Track Shoe Bolts: How Urgent Is It, and What Size Do I Need?

Deal with them soon: a loose shoe can shift or fall off and damage the track rail or undercarriage, so retighten the bolts to the torque in your machine’s manual.

Replace any bolt with a damaged thread, and order by the measured thread and length of an old bolt. We list metric and imperial sizes, such as M12, M20 and 5/8in. Length matters too: M20 x 55mm and M20 x 64mm track bolts are both listed for the Case CX210B.

What Should I Check Before I Order?

• the joint on your chain: a slide-in master pin held by a retainer, a press-fit master pin, or a two-piece master link
• the exact model on the machine plate, including suffixes: the Case CX210B, CX210B LR and CX210B NLC each have their own kits
• the thread and length of an old track bolt, measured rather than guessed
• how many bolts you need (count the shoes and the holes in each); track nuts are listed separately
• whether only the adjuster’s grease nipple has failed: we list nipples for Caterpillar, Hitachi, Case, Daewoo, Volvo and JCB machines

Browse the Under Carriage Hardware range, or contact the PartsForMachines team by WhatsApp, telephone or email with the machine model, serial plate and photos of the pin ends or an old bolt.

Product options, delivery options and returns terms are shown on each product page. A 30-day return policy applies to eligible items.

Frequently Asked Questions

How far should I open the adjuster valve to slacken the track?

Slowly, and only as far as the operator’s manual says. The grease behind the valve is under high pressure, so wear safety glasses and other suitable protective gear, and let it bleed out gradually until the track sags.

Is the grease nipple the same part as the adjuster valve?

Not always. On many adjusters the nipple is fitted to a separate valve, and you slacken the track by easing the valve, not the nipple. If only the nipple is damaged, replace just that, such as the ID13809 grease nipple for the Caterpillar 330D L.

How tight should the adjuster valve go back in?

Use the tightening figure in the manual rather than guessing. Then re-tension the track and check the valve for fresh grease after a short run.

My track adjuster won’t take grease: what should I check?

Start simple: clean the nipple, try a new one and make sure the grease gun is delivering. If grease still won’t go in, don’t force it. The adjuster holds grease under high pressure, so have it checked by a specialist.

The shoe holes won’t line up after refitting: should I slacken the bolts?

Yes. Back the bolts off so the shoe sits flat on the link, start every bolt by hand, then tighten them all with a torque wrench to the manual’s figure.

Can I reuse seized track shoe bolts once they’re free?

Only if you’re sure they’re sound. If a thread is damaged, or you’re in any doubt, fit new bolts of the same measured thread and length. Track nuts are listed separately, so add matching nuts to the order.

Can a dozer-style split master link go on an excavator chain?

Only if that chain is built for one. A chain is joined either by a master pin or by a two-piece master link, and they are different joints, so match the one your chain already has. If you’re unsure, ask us.

Why do some parts say Type 1 or Type 2?

They separate two different fitments listed for the same machine model. On the Caterpillar 307B, Type 1 and Type 2 have different track pitches and bolt sizes, so compare your old part or send our team a photo and serial plate details.