Trailer Wheel Offset: What Dexter Recommends and How to Match a Replacement Wheel

Wheel offset is easy to overlook when you buy a replacement trailer wheel, but Dexter treats it as one of the most important wheel specs. The wrong offset puts uneven load on the wheel bearings and can lower the load your axle can carry. This guide covers what offset is, what Dexter recommends, how to match a replacement wheel, and how to torque the wheel nuts once the wheel is on.

On a Dexter axle, always follow Dexter's instructions. Where a Dexter bulletin and the catalog or manual disagree, the bulletin is the newer instruction.

Key takeaway

• Use zero offset: Dexter Product Bulletin 404 recommends wheels with zero offset, or within 1/2" positive or negative, on Sprung and Torflex axles rated up through 15,000 lbs.
• Match the original: Dexter Product Bulletin 409 says to match any replacement wheel to the same offset as originally equipped. Failure to match offset can reduce the load carrying capacity of your axle.
• Use trailer wheels: Bulletin 404 says automotive or non-trailer wheel designs can result in incorrect offset or fitment.
• Check the threads: Per Bulletin 409, after torquing there should generally be about three stud threads visible past the end of each wheel nut.

What wheel offset means

The Dexter service manual and Bulletin 409 define offset as the relationship of the center line of the tire to the hub face of the axle. Bulletin 404 shows three cases: outset, zeroset and inset. With a zero offset wheel, the center line of the tire lines up with the hub face.

Inset, outset and offset

The Accuride 2025 Wheel Product Catalog defines the terms by where the rim centerline sits compared with the mounting surface of the wheel disc, the face that bolts against the hub or drum. Each is a lateral (side to side) distance, measured from the rim centerline to that mounting surface.

Accuride uses inset or outset for a wheel that cannot be used in a dual application, and offset for any wheel that can be assembled as a dual. Its dual spacing, the distance from one wheel centerline to the other, is found by adding the two wheel offsets.

Most single steel trailer wheels in the TrailStar 2020 catalog, from 12" through 16", are listed at zero offset. The 16" x 6" silver modular wheel with an 8 on 6-1/2" bolt pattern (128702GCC) is listed at +.05", which is nearly zero offset and well inside Dexter's 1/2" recommendation. With a zero offset wheel the tire center sits on the hub face, so the track of the trailer equals the hub face measurement. Dual wheels are a different case: TrailStar lists its 16" silver dual wheels at 5.5" offset. For more on hub face, see How to Measure for a Custom-Built Dexter Trailer Axle.

Dexter wheel offset recommendations

Bulletin 404 applies to single and dual wheel applications on Sprung and Torflex axles rated up through 15,000 lbs. Wheels outside the recommended range can unevenly bias load on the bearing set, severely decreasing bearing life and potentially creating a catastrophic failure.

Nev-R-Lube cartridge bearings have their own, tighter limits:

Bulletin 404 does not apply to Dexter's agricultural product line. The Dexter applications guide also warns not to run a dual wheel as a single unless the hub was made for that, because the offset ruins the bearing life.

The minimum overhang listed on each Dexter beam page is based on zero offset wheels. See Build a Complete Dexter Trailer Axle.

Choosing a replacement wheel

Bulletin 409 lists the wheel characteristics to check before you buy a replacement:

• Bolt circle: Some bolt circles vary by so little that an improper wheel might still attach. Match the wheel to the axle hub, bolt circle, hub pilot and wheel mount surface to hub face, and confirm the studs stick out properly.
• Capacity: The wheels need enough load carrying capacity and pressure rating to match the maximum load of the axle, tire and trailer. Two wheels and tires must equal or exceed the axle capacity.
• Offset: Match the offset of the original wheel.
• Rim contour: Replacement tires must meet the same specifications as the originals. Mismatched tires and rims may come apart with explosive force.

Do not repair or modify a wheel. Even minor modifications can cause a dangerous failure. For capacity, see Choosing Trailer Axle Capacity: Hitch Weight, GAWR, Wheels and Tires. Verify fitment before ordering or contact Southwest Wheel for assistance.

Shop by wheel size:

• 12" Trailer Wheels, Tires and Assemblies
• 13" Trailer Wheels, Tires and Assemblies
• 14" Trailer Wheels, Tires and Assemblies
• 15" Trailer Wheels, Tires and Assemblies
• 16" Trailer Wheels, Tires and Assemblies

Wheel nut torque and thread engagement

Bulletin 409 says to always consult the wheel manufacturer for the right torque for your wheels. Use only fasteners matched to the cone angle of your wheel, usually 60 or 90 degrees. Then attach the wheel:

1. Start all nuts or bolts by hand to prevent cross threading.
2. Snug the nuts to about 10 ft. lbs. to align and seat the wheel on the hub, in the order shown in the bulletin's torque sequence diagram for your bolt count.
3. Tighten in stages, following the same sequence, to the values in the table below.
4. Torque before first road use and after each wheel removal. Check and retorque after the first 10 miles, 25 miles and again at 50 miles, then check periodically.

Wheel nuts are designed for full thread engagement with the wheel stud. Stud threads should be visible outside the nut. The amount varies with the center disc thickness and nut thickness, but in general there should be about three threads visible past the end of the nut.

All rows above use 60 degree cone nuts. Bulletin 409 also lists 16.5" x 9.75" and 17.5" hub pilot wheels with different nuts and values; check the bulletin or the wheel maker for those.

Frequently asked questions

What wheel offset does Dexter recommend?

Zero offset, or within 1/2" positive or negative, per Dexter Product Bulletin 404. Nev-R-Lube hubs have tighter limits.

Can I use a wheel with a different offset than the original?

Dexter Product Bulletin 409 says to match any replacement wheel to the same offset as originally equipped. Failure to match offset can reduce the load carrying capacity of your axle.

Can I put car or truck wheels on my trailer?

Bulletin 404 says Dexter's product lines are trailer specific, and automotive or non-trailer wheel designs can result in incorrect offset or fitment. Consult the wheel supplier or manufacturer.

What does wrong offset do?

It can unevenly bias load on the bearing set, severely decreasing bearing life and potentially creating a catastrophic failure. For bearing service, see Trailer Hub Bearing Adjustment and Grease, Step by Step.

How many threads should show past the wheel nut?

In general about three, per Bulletin 409. The exact amount varies with the wheel center disc and nut thickness.

When should I retorque the wheel nuts?

After the first 10, 25 and 50 miles, then periodically, and every time the wheel is removed. U-bolts have their own torque values; see U-Bolt Torque and Replacement for Trailer Axles.

New to these terms? See Trailer Axle Terms: A Plain-English Glossary.

Southwest Wheel - Your Trailers Best Friend Since 1919.

References

• Dexter Product Bulletin 404, Wheel Offset Recommendations, March 26, 2019, page 1.
• Dexter Product Bulletin 409, Wheel Attachment and Torque Requirements, October 14, 2019, page 1 (Wheel Selection; Torque Requirements), page 2 (Wheel Installation Torque Sequence) and page 3 (Torque Sequence).
• Dexter Trailer Axle Service Manual, 2,000 to 8,000 lb., page 59 (Nev-R-Lube Drums/Bearings), page 71 (Wheels: Wheel Selection), pages 72 and 73 (Torque Requirements; Wheel Torque Requirements).
• Accuride 2025 Wheel Product Catalog, page 39 (Offset vs. Inset/Outset) and page 42 (Rim/Wheel Glossary: Inset, Outset, Wheel Offset, Dual Spacing).
• TrailStar 2020 Catalog, page 6 (Trailer Wheels - Steel) and page 7 (Trailer Wheels - HD Steel: Silver Dual).
• Dexter Light Duty Catalog LIT-122-00, page 6 (Introduction: What is Nev-R-Lube).
• Dexter Axle applications guide for specifying running gear, LIT-008-00, page 7 (Trailer Design Considerations) and page 8 (Wheels and Tires).