How to Choose a Truck Spare Tire Carrier? | Mounting Basics

Ending up with a spare that won’t fit, or a carrier that scrapes on every driveway, starts long before installation. The right choice hinges on three decisions: where it mounts, how much weight it holds, and whether the wheel’s bolt pattern matches the hardware. Work through those, and the install is straightforward.

Start With The Mounting Location

Truck spare tire carriers attach in one of three places: the bed, the bumper, or the trailer frame. Your choice depends on what you drive and where you want the weight.

For pickup trucks, a universal truck bed spare tire carrier is the most common option. Roadmaster’s installation manual for its heavy-duty carrier notes the unit bolts to 4″ box bumpers or C style truck bumpers, so bumper-mounted carriers suit trucks with those factory or aftermarket bumpers. Bed-mounted carriers hold the tire upright against the bed wall and keep it out of the weather.

Trailer owners typically clamp the carrier to the frame. The instruction sheet for Roadmaster’s trailer-mounted carrier says to “identify a safe location on the trailer frame,” then clamp the carrier in place and tighten the hardware. A separate fitting guide notes the mounting plate uses multiple hole patterns, so one carrier can fit several frame sizes. Hitch-mounted carriers slide into a receiver tube — one Roadmaster manual references a motorhome hitch receiver as the mounting point.

Whatever the mount, check the departure angle. One spare tire carrier PDF requires the carrier stay within the trailer’s departure angle and allow curbside access to the winch extension. A carrier that hangs low will drag on slopes.

Match The Load Rating To Your Tire

The carrier’s weight rating must comfortably exceed your tire and wheel combo.

Verify Wheel Fit And Bolt-Circle Size

Not every wheel fits every carrier. The bolt-circle diameter — the circle drawn through the center of the lug holes — must match the carrier’s mounting plate. One Roadmaster instruction sheet provides a fit chart and explains you’ll use different holes or bolt lengths for smaller vs larger bolt circles.

Before tightening anything, use the spare tire itself as a guide. The same sheet says to determine a suitable mounting location and check for proper clearance before tightening. A wheel that rubs the frame or the tailgate will shake loose over time.

If the carrier blocks the license plate or the light when mounted, plan to relocate them. The general installation guidance notes this possibility, and most states require a visible plate and illuminated tag.

Torque Values And Common Mistakes

Torque specs are not universal, and using the wrong one is the most common installation error. The values differ by product and fastener size, so follow the manual that ships with your carrier.

Examples from the official instructions:

• One trailer tire carrier manual specifies 30 ft lbs for multiple fasteners.
• Another heavy-duty carrier specifies 90 ft. lbs. for mounting hardware.
• An instruction sheet calls for 15–20 foot-pounds on 3/8″ nuts.
• Another specifies 35 ft/lbs for bracket nuts and 50 ft/lbs for lug nuts.

Fastener grade matters too. The universal truck bed spare tire carrier guide references Grade 5, Grade 8, Class 8.8, and Class 10.9 hardware. Keep the fastener grade consistent with what the manual calls for.

The installation order is the same across every manual: position the carrier, hand-tighten the hardware, verify alignment and clearance, then torque to spec. Mount the spare wheel afterward and secure it with the supplied lug hardware.

For a tested rundown of the best options across mounting styles and load ratings, see our roundup of the best truck spare tire carriers.

The right carrier comes down to honest measurement: weigh your spare, measure the bolt circle, and confirm the mount clears the frame.