11/11/2026
CAT 239D tracks are listed in two sizes, 320 x 86 x 49B and 400 x 86 x 49B: 320 mm (12.6 in) or 400 mm (15.7 in) wide, with an 86 mm pitch and 49 links, in C-lug or Z-lug tread. How to measure them, confirm the fit and check the sprockets and undercarriage.
Looking for CAT 239D rubber tracks or CAT 239D tracks? Our catalog lists two track sizes for the CAT 239D (Caterpillar 239D), each in two tread patterns, plus the drive sprocket. This guide gives the CAT 239D track size, how to measure and check the fit, the signs that tracks and sprockets are worn and the undercarriage parts worth checking while the tracks are off.
The short answer
Our catalog lists the CAT 239D rubber track in two widths and two treads, four options in all. Pitch and link count are the same for every option, so the choice comes down to width and tread.
| Track size | Width | Pitch | Links | Tread | Sold as |
|---|---|---|---|---|---|
| 320 x 86 x 49B | 320 mm (12.6 in) | 86 mm | 49 | C-lug or Z-lug | Per track |
| 400 x 86 x 49B | 400 mm (15.7 in) | 86 mm | 49 | C-lug or Z-lug | Per track |
Source: Excavator Parts Direct catalog, November 2026. Sold as a single track (price is per track). Two tracks per machine.
Read the size as width x pitch x links. A 320 x 86 x 49B track is 320 mm wide, has 86 mm between link centers and has 49 links. The letter after the link count denotes the tread or guide type, so match it to the size on your old track.
If the size is still readable on the side of the old track, use it. If it has worn away, take three measurements:
Width
Measure across the track from edge to edge. A CAT 239D track should measure 320 mm (12.6 in) or 400 mm (15.7 in).
Pitch
Measure from the center of one link to the center of the next. Measure over several links and divide, which gives a truer figure than a single gap. Both 239D sizes have an 86 mm pitch.
Links
Count the drive lugs around the inside of the track. Mark your starting lug with chalk so you do not count one twice. Both 239D sizes have 49.
If your pitch and link count come out at 86 and 49, the width tells you which size to order. The link count is the figure most often miscounted, so count twice. Our guide to measuring rubber tracks shows each step with diagrams.
Confirm the model
Read the model plate. Model codes can differ by a single character, and each model has its own listing in our catalog. Order from the listing that matches your plate, and if the plate is hard to read, send us the serial number.
Match the width
Order the width the machine runs on now, and fit the same width on both sides. If the old tracks are missing or the size has worn away, ask us before you order.
Match the tread
Each 239D size is listed in C-lug and Z-lug. Matching the tread on your current tracks is the simplest choice. If you want to change, talk to the team first.
Look underneath first
Before the new tracks go on, inspect the sprockets, idlers, rollers and track adjuster. New tracks on a worn undercarriage wear out sooner.
Our advice
A size that is checked, not guessed, is the quickest way back to work. If anything does not match, talk to the team before you order, so you maximize machine uptime and avoid a return.
These are the checks we recommend on any tracked machine, and they apply to the 239D.
Deep cuts, missing lugs and steel cords showing through the rubber all mean the track is near the end of its life. A track in that state can fail without much warning, so plan the change before it does. Check the inside face too, where the drive lugs meet the sprocket.
If the track keeps going slack after you adjust it, do not assume the track is the cause. A track adjuster with failed piston seals cannot hold tension, and worn sprockets can add to the problem. Here is how to check rubber track tension. The correct tension figure for the 239D is in your machine’s operator’s manual.
When sprocket teeth wear sharp, they stop holding the track cleanly. The track can slip or jump through the sprocket, and the shock load travels into the final drive. If you see or hear this happen, stop and inspect the sprockets before you carry on.
If tracks wear out well before the last set did, check the parts underneath before you fit new ones. Material packing between sprocket teeth, rollers and the track also speeds up wear, so keep the undercarriage clean. Spinning the tracks, unnecessary reversing, high travel speed when it is not needed and always turning in the same direction all add wear too. These five tips to extend rubber track life cover other common causes.
With the tracks off, the whole undercarriage is in plain view. That makes a track change the best time to inspect it. Here is what to look at, and what our catalog lists for the 239D today:
| Part | What to check | Listed online for the 239D |
|---|---|---|
| Rubber tracks | Cuts, missing lugs, exposed cords, tension that will not hold | Yes: 320 or 400 x 86 x 49B, C-lug or Z-lug, per track |
| Drive sprockets | Teeth worn sharp, track slipping or jumping | Yes: 2 per machine, 35.9 lb each |
| Idlers | Worn running surfaces, damaged flanges, oil leaks, play | Not currently listed. Ask the team |
| Rollers | Flat spots, worn flanges, oil leaks, rollers that do not turn | Not currently listed. Ask the team |
| Track adjuster | Track that will not hold tension, grease leaks | See the Track Adjusters range |
Source: Excavator Parts Direct catalog, November 2026.
The sprocket bolts to the final drive and its teeth engage the track to drive the machine. Our catalog lists the CAT 239D drive sprocket at two per machine, one each side, and 35.9 lb each. Sprocket wear is hard to judge by eye, so compare yours with an unused sprocket of the same type. Wear builds faster in reverse and at higher travel speeds. Our guide to spotting a worn sprocket shows what to look for.
Idlers guide the track around the ends of the track frame and work with the track adjuster to hold tension. Check for worn running surfaces, damaged flanges, oil leaks and play. With an idler off, it is also the easiest time to check or replace the track adjuster. Our guide to how track adjusters work explains the common faults. We do not currently list a 239D idler online. See CAT idlers for the CAT idlers we list, or contact us with the serial number.
Rollers carry the machine’s weight on the track. Look for flat spots, worn flanges, oil leaks and rollers that no longer turn, and check every one, including the rollers that are hard to see. We advise changing rollers as a set, because a single new roller sits proud of the worn ones and wears faster. Our guide to bottom rollers and carrier rollers explains the difference, and the CAT track rollers and CAT carrier rollers pages show what we list.
Our advice
If the sprockets show wear, replace them with the tracks. It is one job and one round of downtime, and the new tracks start on a sound drive. If a part you need is not listed, contact us with the serial number and we will check.
Our catalog lists the CAT 239D rubber track in four options and the CAT 239D drive sprocket. Both are on the CAT 239D parts page, and all of our CAT tracks are on the CAT rubber tracks page.
More CAT parts
Our catalog lists two track sizes for the CAT 239D: 320 x 86 x 49B and 400 x 86 x 49B. Both have an 86 mm pitch and 49 links. The difference is the width: 320 mm (12.6 in) or 400 mm (15.7 in). Each size is listed with a C-lug or a Z-lug tread.
We list CAT 239D tracks in two widths: 320 mm (12.6 in) and 400 mm (15.7 in). Measure the track on your machine, or read the size on its side, and order the same width for both sides.
It is the track size, written width x pitch x number of links. The track is 320 mm wide, measures 86 mm from the center of one link to the center of the next and has 49 links. The letter after the link count denotes the tread or guide type, so match it to your old track.
Both treads are listed in both widths for the CAT 239D. The simplest choice is to match the tread on your current tracks. If you want to change tread, tell us how and where the machine works, and the team will talk you through the options.
Yes. We sell CAT 239D tracks individually, and the price shown is for one track. The machine takes two, one on each side.
Our catalog lists two drive sprockets per machine for the CAT 239D, one on each side. Each sprocket weighs 35.9 lb. Check both when you change the tracks.
If the sprocket teeth are worn sharp, or the old tracks slipped or jumped, replace the sprockets with the tracks. Worn sprockets shorten the life of new tracks. Compare yours with an unused sprocket of the same type if you are unsure.
The correct tension figure and method for the 239D are in your machine’s operator’s manual. As a rule, a track that is too loose can come off, and a track that is too tight wears faster, along with the parts it runs on.
Common signs are deep cuts, missing lugs or steel cords showing through the rubber, a track that will not hold tension, a track that slips or jumps on the sprocket, and tracks that wear out much faster than the last set. Check the sprockets, idlers, rollers and track adjuster at the same time.
Related guides
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