Caterpillar240-8240Large Tapered Roller Bearing Cone, Inner Ring with Rollers and Cage, Cone Only (-X Component of the 240-8240 Assembly)

Product Description

What this part is

This is the tapered roller bearing cone from Caterpillar’s 240-8240 bearing assembly — the inner ring complete with its tapered roller set and cage. The trailing -X is Caterpillar’s component suffix for the cone half of the assembly; the cup half carries the -Y suffix, and the bare number 240-8240 refers to the complete cone-and-cup assembly.

What is and is not included

Cone only. There is no cup in this listing. Tapered roller bearings are separable by design because the cup presses into the housing and the cone onto the shaft, so replacing one without the other is routine practice — but if you need a complete bearing, you need the cup as well. Central Surplus stocks complete 240-8240 cone-and-cup sets separately; see the interchange section below.

Decoding the designation

240-8240 — Caterpillar part number for the complete tapered roller bearing assembly.-X — the cone (inner ring with rollers and cage). This listing.-Y — the cup (outer ring), the other half of the assembly.2408240X — the same number written without separators, as it commonly appears in parts systems and search boxes.

About Caterpillar bearing numbers

Worth understanding before you buy, because it explains both the price and why cross-referencing is hard. Caterpillar does not manufacture bearings; CAT-numbered bearings are built to Caterpillar’s specification by Timken, NTN and other makers, then carry a Caterpillar part number rather than the maker’s. That makes them classed as special order — normally available only through Caterpillar dealers, at dealer pricing and dealer lead times.

The consequence is that no published Timken cross-reference exists for 240-8240. Caterpillar does not publish the interchange and Timken does not cross-reference CAT numbers. Some 240-8240 listings, including earlier Central Surplus copy, carry the word “Timken” as a search keyword; treat that as an indication of who is understood to build the part, not as a verified equivalent part number. We are not going to invent a Timken number for it. If you need a non-CAT equivalent, the reliable route is to measure the bearing and match it dimensionally through a bearing engineer.

Dimensions — and a discrepancy you should know about:
The earlier listing data for this part disagreed with itself: the title gave the bore as 8-1/2 in while the description gave 8.25 in. Those cannot both be right, and no published Caterpillar or Timken datasheet for 240-8240 was located to settle it. Rather than pick one and present it as fact, the honest position is that the bore is approximately 8-1/4 to 8-1/2 in with an outside diameter of approximately 12-1/2 in on the mating cup, and the exact figures require measurement.

If you are matching this to a machine, ask and we will caliper the bore and the cone width before you commit. That takes a minute and removes all doubt. Load ratings, cage material, K and e calculation factors and weight are not published for this reference and are deliberately omitted rather than borrowed from a similar-sized standard series.

Condition

New old stock, made in USA, with staining visible in the photographs. The staining is surface discolouration from long storage, not raceway damage — but review the images and ask for more if anything is unclear. This is disclosed openly rather than glossed over.

Fitting notes

The cone presses onto the shaft. On a bearing this size, heat mounting is the sensible method; if you press it, push on the inner ring face with a proper fitting tool and never against the cage or the rollers.

Tapered roller bearings carry no built-in internal clearance. The operating endplay or preload is created at assembly by how far the cone is drawn up against the cup, and on a large final-drive or wheel-end bearing that setting is the single biggest determinant of service life. Set it to Caterpillar’s specification for the machine rather than by feel, and re-set it rather than reusing an old shim pack, because a new cone changes the stack-up.

Interchange guidance

Cross-references: 240-8240-X, 2408240X, 240 8240 X, 2408240-X. Parent assembly: 240-8240 (2408240). Mating cup: 240-8240-Y (2408240Y).

Central Surplus also stocks complete 240-8240 cone-and-cup sets under SKUs BJ5#EVOJMK and BE6#OSOXGD. If you need both halves, buy the set rather than sourcing the cup separately.