Jeep Wrangler JK Trail Master 4.5-Inch Suspension Kit

129 1105 Wrangler Jk 4 5 Inch Suspension Kit By Trail Master Jep Wrangler At Bonneville Salt Flats

The Jeep Wrangler JK Unlimited is arguably one of the most iconic 4x4s ever built. The ability to handle extreme challenges, such as the Rubicon Trail in factory trim, always impresses us. More so when you add the ability to haul the kids to practice, grab groceries on the way home from work, and even take grandma out to the local disco with four of her senior-diva cohorts, you have a vehicle that truly does it all.

However, even with its trail-friendly demeanor and savvy ability to handle that day-to-day runaround, something simply looks wrong about a four-door JK in stock form-and we're sure grandma's diva friends would agree. The stock tires are just too small. So, like any diehard automotive enthusiasts would, we turned to the aftermarket to solve the problem. We wanted to clear a 37-inch tire to achieve a balanced look while also improving approach, departure, and breakover angles at the same time. We settled on a Trail Master 4.5-inch short-arm suspension lift. Trail Master has been in the lift kit business for nearly 30 years, and despite the trend that so many others have succumbed to in recent years (moving manufacturing overseas), Trail Master has remained profitable on U.S. soil, keeping Americans working in their hometown of Chino Valley, Arizona. Follow along as we highlight the attributes of Trail Master's latest product offering, and improve the look and functionality of Jeep's legendary JK Unlimited.

How It Works
We drove our lifted JK back to California from Utah to evaluate the kit's road manners. On the highway the ride felt firmer than stock, but not too stiff for everyday use. On the way home, we took a two-day detour over the Rubicon Trail during the annual Jeeper's Jamboree. This gave us a good chance to understand how the kit handled high-flex events, general rock rash, and deep water crossings. One of the things we noticed immediately after arriving in Rubicon Springs was a slight tear in the factory upper bumpstop jounces. This damage was caused by the edges of the aluminum bumpstop extensions cutting into the foam at full compression. Luckily, the engineers at Trail Master are also avid Jeepers and were present at Jeeper's Jamboree. We spoke to the Trail Master lead suspension engineer and explained the issue. The next week, we had a pair of redesigned bumpstop extension in our mailbox. All it took to correct the problem was a slight chamfer or radius to the inner and outer dimensions of the tops of each aluminum puck. We were impressed with how quickly Trail Master took our input, addressed the issue and made changes to the product. After nearly 12,000 miles of pavement, four additional trail runs, and a weekend of sand dune running at Pismo State Beach, we have no issues to report with the Trail Master suspension system. The kit is free of noise and continues to perform as expected.

129 1105 Wrangler Jk 4 5 Inch Suspension Kit By Trail Master Tom Wood Custom Driveshafts

Get the Shaft
Trail Master offers their JK lift system with upgraded driveshafts to complete the kit; however, since we were up in the Salt Lake City area for this install, we hooked up with our good friends at Tom Wood's Custom Driveshafts to photograph the process of manufacturing a pair of heavy-duty replacement drive shafts from scratch. We plan to show you how these awesome shafts are made in a coming issue, so stay tuned.

This is the complete 4.5-inch Trail Master suspension system as we received it. The kit came well packed in manageably sized cardboard boxes. We appreciate the fact that all mounting hardware was sealed in individually labeled plastic bags for easy identification. Additionally, the system included detailed installation instructions with color photos.
This is the complete 4.5-inch Trail Master suspension system as we received it. The kit ca
Before: In stock form, our JK achieved 23.5 inches of vertical travel before a tire would lift off the ground.
Before: In stock form, our JK achieved 23.5 inches of vertical travel before a tire would
After: With the front sway bar disconnected, our modified JK bested the stock score by eight inches, netting 31.5 inches of vertical travel before a tire lifted off the ground.
After: With the front sway bar disconnected, our modified JK bested the stock score by eig

Here, you can see the new stainless-steel braided brake lines included with the kit. Aside from being longer in length to accommodate the additional flex afforded by the kit, these lines also help improve brake pedal feel, thanks to the added rigidity of the stainless braid. A Teflon sheath protects the stainless braids from the elements.
Here, you can see the new stainless-steel braided brake lines included with the kit. Aside
This photo shows how the mounting arrangement for the axle-side of the front track bar, which is made from 1.25-inch-thick, 0.250-inch-wall DOM tubing. A 3/4-inch rod end is used at the axle end to reduce any binding while out on the trail. Like all components of the kit, this track bar is coated with an attractive Silver Vein powdercoat finish.
This photo shows how the mounting arrangement for the axle-side of the front track bar, wh
The changes to the rear track bar arrangement are slightly different than the front. Using a heavy-duty relocation bracket with the OEM track bar, the mounting point is relocated a few inches higher on the axle-side. When it comes to the added stress and leverage that these parts will be subjected to in rockcrawling, reliability is key, and by the looks of this bracket, Trail Master knows it. We like the fact that it utilizes five mounting bolts to secure it to the axle assembly.
The changes to the rear track bar arrangement are slightly different than the front. Using

Jack-It's lead mechanic, Kyle Boddy, is shown installing one of the upper tubular link arms for the front suspension. These links are made from 1.5-inch DOM tubing and feature extra-long tapered weld bungs and a durable powdercoat finish. The extra bung length ensures that the joints will have plenty of thread engagement while also allowing gobs of adjustability. The lower portion of these links includes fully welded bolt tabs that attach to the top of the axle assembly. The lower ends of these links employ durable polyurethane with zinc-impregnated bushings. The chassis-side of the upper link arms features Trail Master's rebuildable flex joints to provide years of noise-free operation. The lower link arms are very similar except for the fact that they are manufactured from 2-inch DOM tubing and use a flex joint at each end.
Jack-It's lead mechanic, Kyle Boddy, is shown installing one of the upper tubular link arm
This photo shows how the factory steering stabilizer is relocated to the top of the tie rod. We like this arrangement because it places the shock up out of harm's way.
This photo shows how the factory steering stabilizer is relocated to the top of the tie ro
Due to the additional inches of elevation, the factory bumpstops required extensions to ensure proper operation. Here, Boddy drills a hole in the OE bumpstop landing to make way for new mounting hardware. This hole will allow the aluminum bumpstop extensions to be bolted to the axle assembly.
Due to the additional inches of elevation, the factory bumpstops required extensions to en

The process of installing the coil springs is much easier with a spring compressor tool as shown here. Trail Master makes no mention to this in the supplied instructions, but Jack-It's crew knew the drill.
The process of installing the coil springs is much easier with a spring compressor tool as
All JK axles feature stamped lower coil spring pads that are welded in place at the factory. As such, these brackets are set up exclusively for the factory-recommended pinion angle. This arrangement can cause problems when the pinion angle is altered. During extreme flex events, the driver-side rear coil spring can come into contact slightly with the rear track bar-making an annoying noise in the process. To combat this, Trail Master offers new heavy-duty, fabricated spring pads that allow you to clock the coil springs forward a few degrees to eliminate the problem. This photo shows the new spring pads in place awaiting welding. Before welding these mounts, Boddy lowered the vehicle so that the weight of the vehicle was present-in other words, these pads were welded last.
All JK axles feature stamped lower coil spring pads that are welded in place at the factor
Here, you can see the new antisway bar quick-disconnects included with the kit. This setup makes it easy to disconnect the antisway bar on level pavement prior to accessing the trail. The system uses two quick-release pins to secure the end links during highway use. We suggest carrying a couple of spare quick-release pins in the vehicle just in case you accidently misplace a pin while out on the trail as we did.
Here, you can see the new antisway bar quick-disconnects included with the kit. This setup

Due to the fact that we planned to run the factory wheels for a few weeks with the new suspension system installed, a set of 2-inch wheel spacers were required. We sourced the steel units shown here from TeraFlex. Without these spacers, the rear tires would have made contact with the rear upper control arms, rendering the vehicle undrivable. Ideally, you would want to have a wheel with a 4.5-inch backspacing or 1.5-inch wheel spacers to prevent this issue.
Due to the fact that we planned to run the factory wheels for a few weeks with the new sus
The Rubicon Trail gave us a good chance to test the new suspension system under our '07 JK Unlimited.
The Rubicon Trail gave us a good chance to test the new suspension system under our '07 JK
This is the point when the aluminum bumpstop extensions made contact with the factory foam jounces, causing slight tearing in the process. Keep in mind that this is an extreme flex event, only applicable when the sway bar is disconnected and the vehicle is in highly challenging terrain-not exactly what the kit was designed around, but that didn't keep Trail Master from resolving the issue.
This is the point when the aluminum bumpstop extensions made contact with the factory foam

SOURCES
TeraFlex 5241 S Commerce Drive Murray UT 84107 801-288-2585 www.teraflex.biz	Trail Master Suspension P.O. Box 3450 Chino Valley AZ 86323 928-636-7080 www.trailmastersuspension.com
Tom Wood's Custom Driveshafts 2147 N. Rulon White Boulevard Suite #103 Ogden UT 84404 801-737-0757 www.4xshaft.com