NTNLM603049/LM603011Two-Row 2TS Matched Tapered Roller Bearing Assembly 1.7812″ Bore x 3.0625″ OD – Complete 6-Piece Pre-Set Assembly

Product Description

What this part is

This is a complete two-row (2TS) matched tapered roller bearing assembly built from LM603049 cone and LM603011 cup members, supplied under the assembly number LM603049-90033. It is not a bare cone, not a bare cup, and not a single-row set. It is one pre-configured assembly, factory-selected so that its members work together to produce a specific internal setting, and it is sold and shipped as one item.

Quantity and configuration — read this before you order:
The on-hand quantity reads 1 while the condition note says 6 pieces. Both are correct, and the apparent conflict is worth resolving precisely because it is the single most valuable piece of information on this page. There is one assembly available, and that one assembly comprises six individual bearing pieces. It is not six sellable bearings and it is not six separate single-row sets. Piece by piece, what is in the box:

2 × LM603049 — standard cones (inner rings with tapered rollers and cages)2 × LM603011 — standard cups (outer races)1 × LM603049XF — special-feature cone1 × LM603011EX — special-feature cup
That is six pieces forming one two-row assembly with special-feature cone and cup members. If you need two independent single-row taper positions on two different shafts, this is not the right purchase — see the warning about splitting the set further down.

Decoding the designation

LM603049 is the cone (inner ring plus roller and cage assembly). LM603011 is the cup (outer race). Together LM603049/LM603011 is the standard single-row set designation. The trailing -90033 is an assembly number in the Timken-style convention adopted across the inch tapered roller bearing industry: a dash number in the 90000 range identifies a specific pre-configured matched assembly rather than a loose component. So LM603049-90033 does not mean “an LM603049 cone with something added” — it means a defined, catalogued build. That is why the box contains six pieces and not two. If someone quotes you a plain LM603049 or a plain LM603049/LM603011 against this listing, they are quoting a bare cone or a single-row set, which is a fundamentally different and much cheaper item.

On the special-feature suffixes: XF on the cone and EX on the cup denote members that differ from the base part in some controlled respect — typically a modified width, face or raceway feature. In an assembly like this one, those modified members are what set the internal spacing and therefore the endplay or preload of the finished two-row unit.

Published single-row dimensions

Bore d: 1.7812 in / 45.242 mmCup outside diameter D: 3.0625 in / 77.788 mmSingle-row assembly width T: 0.7812 in / 19.842 mmCup width C: 0.5937 inCone width B: 0.7812 inWeight: approximately 0.37 kg per single-row set
These are the dimensions of one row. The overall width of the assembled two-row unit depends on the special-feature members and on whether a spacer is used, and that overall figure is not published for the 90033 configuration — measure it or request it before finalising a housing design.

Load ratings are not published for this configuration

We are not going to put load ratings on this page. Two-row assembly ratings for the specific 90033 build are not published, and quoting the single-row LM603049/LM603011 ratings instead would materially understate what a two-row assembly can carry — a two-row unit’s rating is not simply the single-row figure, and it is not simply double it either, because the load sharing between rows depends on the setting and on the direction of the applied load. An honest gap is more useful to you than a borrowed number. If you need rated capacity for a calculation, request it from NTN or Timken engineering against the assembly number LM603049-90033.

Why a two-row taper assembly instead of two single-row bearings:
A single-row tapered roller bearing carries radial load and thrust in one direction only. It has to be opposed by a second bearing to handle thrust the other way, and even then the pair has to be set correctly at assembly. A two-row matched assembly does three things a single-row set cannot:

Thrust in both directions. The two rows oppose each other internally, so the unit takes axial load either way without needing a second bearing position to react it.Moment (overturning) load resistance. Because the two rows are axially separated inside one unit, they generate a couple that resists tilting of the shaft. A single-row taper has effectively no moment capacity — it is a point support. This is why two-row assemblies show up in wheel ends, overhung pinions, spindle noses and anywhere a cantilevered load tries to cock the shaft.Setting comes pre-established. The internal endplay or preload is determined by the assembly’s own members rather than by shims and a mechanic’s dial indicator, which removes the biggest source of variability in a taper installation.

2TS-DM versus 2TS-IM — direct and indirect mounting

Two-row taper assemblies are built in two orientations, and the difference determines how much moment load the unit can take:

2TS-DM (direct mount) — the two cups are back to back. The effective load lines converge outside the bearing, which gives a narrower effective spread and therefore lower moment stiffness. This is the arrangement used when the assembly is essentially a compact radial-plus-thrust support.2TS-IM (indirect mount) — the two cones are back to back. The effective load lines diverge, giving a wider effective spread and substantially better resistance to overturning moments and to shaft misalignment under load.
Which orientation you need is set by the machine design, not by preference — a housing built for a direct-mount unit will not correctly locate an indirect-mount one. Confirm the orientation of this specific assembly from the photographs, or ask us to check the faces, before committing it to a critical position.

Why the six pieces must stay together

The XF cone and EX cup are the members that establish the internal spacing and therefore the setting of the assembly. That has a direct practical consequence: do not split these six pieces across two separate single-row bearing positions. If you break the set up and use, say, one standard cone with one standard cup in one location and the XF/EX members in another, neither position will be at a known setting, and the special-feature members in particular will produce an endplay you have no data to interpret. The pieces were selected and finished as a group and belong together. If you do need to reconfigure them for some reason, the whole assembly must be re-set from scratch to a specified endplay or preload with the correct measuring procedure — not eyeballed.

Fitting notes

Cones are an interference fit on the shaft; cups are a press or transition fit in the housing. Drive each member using a tool that bears on the ring face only, never on the rollers or cage. Keep the members in the orientation they were supplied in and keep them clean — the setting of a matched assembly is measured in thousandths of an inch, and a burr or a trapped chip on a mating face is enough to change it. Do not intermix these members with cones, cups or roller-and-cage sets from other production lots or other assemblies; roller and cage geometry is controlled within a lot to produce the specific setting this unit was built to.

Interchange guidance

Useful search and cross-reference forms for the members and the set:

LM603049 (cone), LM603011 (cup)LM603049XF, LM603011EX (special-feature members)LM603049-90033 (this assembly number), LM603049/LM603011, LM603049/11Metric envelope: 45.242 × 77.788 × 19.842 mmTimken LM603049/LM603011, SKF LM603049/11, Koyo LM603049R
The LM603049/LM603011 basic numbers are industry-standard inch taper numbers produced to a common envelope by NTN, Timken, SKF, Koyo and others, so the single-row members cross cleanly. The assembly number LM603049-90033 does not cross as generically — assembly dash numbers are specific builds, and another manufacturer’s 90033 is not guaranteed to be the same configuration. Match on the assembly number where you can, and confirm the piece content when you cannot.