The Story of Jeep’s Iconic Rear-Mounted Spare Tire

As aforementioned, Jeeps have utilized an exterior-mounted spare tire since their conception in the mid-1940s. During the days of military MBs and GPWs, these chassis featured a rear-mounted spare tire, similar to Jeep Wranglers; however, this placement faced issues with the release of 1945’s Willys CJ-2A.

When Willys engineered the CJ-2A, the company made several adjustments to the tub to make the “jeep” more palatable to civilians. Aside from removing firearm racks and ditching the matte olive-drab paint job, Willys opted to redesign the rear of the tub to accept a pickup-truck-esque tailgate, ideal for transporting farm equipment and supplies. Unlike the MB, which featured a solid rear tub, the CJ-2A required additional clearance to operate the tailgate, leading designers to shift the spare tire carrier to the passenger rear of the tub, just behind the rear tire.

This design remained through several Jeep generations, including the CJ-3A, CJ-3B, and even some early CJ-5 and CJ-6 models! However, with the release of the all-new CJ-7 in 1976, the CJ platform received a rear-mounted, swing-out spare tire carrier, allowing the spare tire to mount in its original position while retaining an operational tailgate. This design remained through the end of the CJ’s production when Jeep replaced it with a solid-mounted option on the YJ; while still positioned at the rear of the Jeep, the new spare tire carrier bolted to the YJ’s tailgate, allowing you to open the tailgate in a single motion.

Though differing in position and design across generations, there've been a couple of constants in Jeep’s spare tire setup. Firstly, the spare tire is always mounted externally. Secondly, it’s always been full-sized; no dinky donut spares here! With these constants in mind, let’s consider some of the reasons behind Jeep’s iconic spare tire positioning.

Ease of Access

First on the list is the ease of access; rather than cramming the spare tire beneath the chassis or inside the cargo area, where it’d likely be trapped under tools, cargo, and assorted gear, Jeep opted for an easily-accessible mounting location.

Maximize Cargo Space

The Jeep CJ and Wrangler chassis, especially pre-Unlimited models, aren’t renowned for their cargo capacity; can you imagine the volume an interior-mounted full-size spare tire would consume? Positioning the spare tire externally gives room to your Jeep’s interior space for camping gear, recovery equipment, tools, and anything else that’d be handy on the trail! 

Retain Maximum Ground Clearance

Another common suggestion is mounting the spare tire between the rear frame rails, as several pickup trucks and SUVs do; however, this poses several issues. For starters, this location housed the gas tank on most Jeeps. Additionally, Jeeps are renowned for ground clearance; it’s one of the premier characteristics that allows Wranglers and CJs to be such domineering forces on the trail! Mounting the spare tire beneath the chassis would only harm a Jeep’s ground clearance and departure angle, thus hindering performance off-road. 

Ditch the Donut!

With minimal space to mount a full-size spare in or beneath the cargo area, it’s only natural to question Jeep’s decision not to run a compact or “donut” spare tire. While convenient due to their space-saving design, donut spares are rather limited functionality-wise, featuring speed limitations and reduced durability; imagine getting a flat on the trail and crawling out on a donut! 

Jeep’s externally mounted spare tire carriers provide the clearance necessary to mount a full-sized spare tire, meaning that, as opposed to vehicles with a compact spare, you won’t have to adjust your driving habits after installing the spare tire.

Aesthetics

While not originally intended to boost aesthetics, modern Wranglers likely retain the rear-mounted spare tire as an homage to the vintage CJs and Wrangler generations that previously commanded the roads and trails. After nearly eighty years of externally-mounted spare tires, spotting a Jeep without one would look unnatural!

Top Jeep Spare Tire Customizations

While your Jeep’s factory spare tire carrier can withstand the weight of a factory-size tire, issues arise when installing heavy, oversized tires, especially while off-roading. Check out some of our favorite products to bolster your Jeep’s spare tire mount!