What Is the Best Drive Sprocket for Caterpillar 304C CR and 305C CR Excavators?

The drive sprocket for a Caterpillar 304C CR and 305C CR is part number 260-6341 - a 19-tooth, 12-bolt sprocket that Caterpillar also lists against the 305.5D, 305.5E and 305.5E2. That number is the answer, and it is worth naming before anything else, because "304C CR" and "305C CR" between them cover machines whose sprockets are not interchangeable with the rest of the 304 and 305 range.

Last updated: October 5, 2026

This guide covers what the drive sprocket does on these compact radius machines, how to confirm 260-6341 against your serial number, how the sprocket is identified by its teeth and bolt count, how to tell a worn sprocket from a worn chain, and how to buy one in Canada with the documentation that matters.

What the sprocket does, and what CR means

The drive sprocket is the toothed wheel on the final drive that engages the chain's bushings and pulls the track. Every other undercarriage component - idler, rollers, the belt itself - is either holding the chain in line or carrying weight; the sprocket is the one converting torque into travel. That is why its tooth profile and its pitch have to match the chain exactly, and why a sprocket that is running out of line wears the belt and itself at the same time.

CR in Caterpillar's mini excavator naming denotes the compact radius version of the machine - the short-tail configuration used where the excavator has to work against a wall, in a trench or on a single lane. The undercarriage on those machines is narrower than on the standard-tail equivalent, and the sprocket is part of that package, which is the practical reason a 304C CR sprocket is not simply a 304 sprocket.

Confirming 260-6341 on your machine

Four checks, all taken from the sprocket you are removing.

The part number against your model and serial number. This is the fitment answer, and it should come back in writing - 260-6341 is the number listed for the 304C CR and 305C CR, and the same number carries the 305.5D, 305.5E and 305.5E2. Tooth count and bolt count, 19 and 12 on this sprocket, which is how the part is identified in every listing and manual. The mounting pattern - bolt circle, bolt size and the pilot or bore diameter - measured on your own final drive rather than assumed from a photograph. And the hub height and tooth profile, because a sprocket can be dimensionally close and still not engage the chain correctly.

The cleanest confirmation is to hold the old and new sprockets side by side with the old one still clean: teeth, bolt holes, pilot diameter and hub depth can all be compared directly, and a difference in any of them is a stop.

Before the sprocket comes off, two observations are worth making on the machine. Check the chain for stretched pitch at the same time, because a sprocket is rarely worn alone - the same hours and the same ground wear both, and one will pull the other out of shape. And look at how the chain sits on the teeth through a full rotation: a chain that rides up one side of the teeth tells you the final drive is not running true, which is a different repair from a new sprocket.

Do not confuse the neighbouring numbers

Caterpillar's 304 and 305 families do not share one sprocket, and that is the trap. The 158-4795 sprocket is listed against the 304, 304.5, 304CCR, 305 and 305.5; the 260-6341 is the one listed for the 304C CR, 305C CR, 305.5D, 305.5E and 305.5E2; and 264-5371 covers the 303.5C, 303.5E, 303C CR, 303.5C CR and 304D CR. Three numbers, three groups of machines, and a machine can move between them across a generation change.

Which is why the discipline that matters here is identical to the one used for a drive sprocket 260-6341 for Caterpillar excavators and, on another colour of machine, in what makes a drive sprocket right for these two models: quote the number, then verify the dimensions. The same reasoning runs through how a high-quality replacement sprocket is identified on Hitachi EX200 and EX400 machines.

Reading a sprocket that is coming off

A sprocket wears into a hook. Look at the tooth from the side: a new sprocket's tooth has a flat, square drive face, and as it runs that face curves forward until the tooth looks like a hook. Once the hook is formed, the chain no longer seats properly - it climbs the teeth under load, the pitch stretches, and both parts wear faster together.

Four observations cover the diagnosis. Hooked or sharpened teeth mean the sprocket is finished. Wear concentrated on one side of the teeth means the chain is running out of line, and a replacement will wear the same way. Chipped or cracked teeth point at impact or a foreign object in the chain, and the chain should be inspected link by link. A shiny, polished tooth face with little hook is normal running-in, not a reason to replace anything. Noise, a chain that will not hold pitch, or a machine that climbs out of the chain when it pushes are the symptoms the operator notices first.

Buying a sprocket in Canada

Four items belong in writing: the part-number cross-reference for your model and serial number; the specification as supplied - tooth count, bolt count and mounting dimensions; the warranty terms as a period plus an operating-hours cap, whichever comes first, with freight responsibility named; and the stock position with a delivery date. On a machine that is down, the delivery date is usually the line that decides the purchase.

Two habits make the next replacement cheaper. Fit the sprocket and chain as a pair where both are worn, because a new sprocket under a stretched chain wears quickly and the reverse is just as true. And keep the old sprocket's dimensions on file: on a machine that has been through a generation change or a rebuild, that record is what confirms the part number the next time.

This article is part of the drive sprockets guide, which covers how a sprocket is identified, how it wears and when to replace it with the chain.

FAQs

What is the drive sprocket part number for a CAT 304C CR and 305C CR?

260-6341 - a 19-tooth, 12-bolt sprocket. Caterpillar also lists the same number against the 305.5D, 305.5E and 305.5E2. Confirm the number against your machine's serial number before ordering.

Is the 304C CR sprocket the same as other 304 and 305 sprockets?

No. The 304 and 305 range uses several sprockets: 158-4795 for the 304, 304.5, 304CCR, 305 and 305.5; 260-6341 for the 304C CR, 305C CR and 305.5D/E/E2; and 264-5371 for the 303.5C, 303.5E, 303C CR, 303.5C CR and 304D CR.

What does CR mean on a Caterpillar mini excavator?

CR denotes the compact radius version - the short-tail configuration built to work against walls, in trenches and on narrow sites. The undercarriage is narrower than on the standard-tail equivalent, which is part of why the sprocket is model-specific.

When should a 304C CR or 305C CR sprocket be replaced?

When the teeth are hooked or sharpened, when one side wears faster than the other, when teeth are chipped or cracked, or when the chain starts climbing out of the sprocket under load. Replace a hooked sprocket with the chain rather than running a new one under a stretched chain.

Can I buy an aftermarket sprocket for these models in Canada?

Yes, provided it is documented: a part-number cross-reference, the tooth and bolt counts, the mounting dimensions, and warranty terms with an hours cap. Undocumented, the photograph is the whole product.