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4-Link A 14 Bolt Axle - 4-Wheel & Off-Road Magazine

Fred Williams Brand Manager, Petersen’s 4Wheel & Off Road

The GM Corporate 14-bolt rear axle is hard to beat. Found in 3⁄4- and 1-ton trucks, they are big, strong, and cheap, making them perfect for spinning large tires on homebuilt 4x4s. Jeep TJs and YJs are also pretty hard to beat. They have small bodies, tough frames, and reliable engines. So we decided to take two great tastes that taste great together and dunk a 14-bolt into a Jeep project.

4 Link A 14 Bolt Axle 4 Link And 14 Bolt Installed Photo 41991827

Putting a 14-bolt under a long-wheelbase TJ frame like we did is not a beginner’s project, especially if all you own is a set of wrenches and a ballpeen hammer. For this project you’ll need to cut, weld, and grind at the very least, and an angle finder and tape measure will be needed as well to put one in. But using some quality aftermarket parts, such as a complete truss and link system from Artec Industries, simplifies the project. This isn’t a weekend job unless you’re a whiz fabricator with some buddies there to help you out.

“The parts come disassembled and need to be welded together”

Our project truck isn’t a stock TJ frame either. It’s actually stretched out to a 116-inch wheelbase. But it’s similar enough that you’ll get the idea of what we did if you wanted to duplicate the job on your TJ. Using the Artec kit on a YJ would be even easier because they have leaf spring mounts available, but for this story we opted for a four-link setup, which can be used on either a TJ or YJ and, with some work, a CJ too. Though designed for a Jeep TJ and YJ the Artec brackets could work on most any 4x4 with a bit of customization.

PhotosView Slideshow Job one of these projects is procuring and cleaning a 14-bolt. We found this one from an ’03 GM with disc brakes for under $200! Prices may vary, but no matter what, you’ll want to cut off all the old factory bracketry.

Job one of these projects is procuring and cleaning a 14-bolt. We found this one from an ’03 GM with disc brakes for under $200! Prices may vary, but no matter what, you’ll want to cut off all the old factory bracketry.

A plasma cutter or torch and grinder help when removing old brackets, we used a Miller Spectrum 375. You’ll want to be careful not to cut through the axletube itself, but if you do, clean it and weld it back up.

We ground all the paint off the axletube all the way around since we were not sure at this point where the new bracket would land. Proper preparation will help get good welds later. We suggest an engine hoist (or a few strong friends) to help move the 14-bolt, and also ear, eye, and nose safety gear when doing a lot of grinding.

The stock TJ rear suspension isn’t bad, but it uses four short links and a track bar. This forces the axle to move side-to-side through its travel. The rear Dana 44 is a great axle, but our goal of 37-inch or larger tires will be maxing it out on strength, especially as we swap in a bigger engine and a nutcase driver.

Most of the old suspension brackets on the Jeep frame needed to be removed as well. The only thing we kept is the upper shock and spring mounts, as we’re keeping it coil sprung, but these would also go if you were going to coilover or air shocks. Again, take care not to cut through the framerails.

The Artec modular 14-bolt truss system can be configured in a variety of designs depending on your needs. The parts come disassembled and need to be welded together, which helps reduce the overall costs such that what you see here is just under $450.

The truss we are using has a pinion guard that bolts to the axle; we installed that first to locate the truss and then tacked the truss together on the axle. We then removed the truss, finish-welded it together, reinstalled it on the axle, and tacked it in place.

The upper link frame mounts are multiple pieces and need to be assembled and welded before going on the frame, so we bolted and clamped them together on the bench first. We used FK rod ends with 25⁄8-inch misalignment spacers, so we used pieces of tubing cut to 25⁄8 inches and bolted them in place to help keep it all in place while welding.

The lower shock and link mounts will also require assembly welding. Note the spacer on the shock mount to set the spacing perfect for your chosen shocks. Low link mounts are available in 0-, 10-, and 22-degree angles in case your lower links are angled inward. All these brackets are a either 1⁄4 or 3⁄8 inch thick, and we MIG-welded them.

We also welded the lower coil spring mounts together and set them in place on top of the axle. We centered and squared the axle where we wanted to clear the fuel tank. Then we set the axle at what we plan will be ride height with about 61⁄2 inches of uptravel from the spring perch to the metal of the bumpstop, and set the pinion angle. Next we lowered the frame onto the axle to get the correct angle of the spring perch at full stuff and tacked it in place.

We added the upper link mounts to the axle and clamped the frame ends to the frame with our 36-inch upper links in place. We squared the axle link mounts to the links so the joints had plenty of movement, verified that the bolts were coming from the outside in so they could be removed, and tacked them to the truss.

The upper frame mount link bracket has an L-tab on the bottom because it is designed to weld on the inside and bottom of the frame, so we clamped it in place. Again at full compression, we tacked the lower axle mounts in place and clamped the lower frame mounts to the bottom of the frame. All our aluminum links came from Wide Open Design in Murfreesboro, Tennessee.

We went with massive aluminum links for strength and weight. The 21⁄4-inch-diameter links were made to our specified lengths with left-hand 11⁄4-inch threads at one end and right-hand threads at the other. This allows easy length adjustment without removal from the vehicle. Our lowers are 40 inches eye to eye, and our uppers are 36, but a stock-wheelbase TJ would probably run something shorter. The massive 11⁄4-inch FK rod ends (Heims) use 5⁄8-inch-thick bolts through misalignment spacers. These rod ends have a radial static load rating of over 100,000 pounds. All the Artec brackets were drilled out to 5⁄8 inch from their standard 9⁄16 inch.

The lower links being mounted to the bottom of the frame bothered us, especially with such a long wheelbase. They may be fine on a stock TJ, but we would surely get hung up on them with 116 inches of wheelbase. We opted to move them up onto the outside of the frame. This, however, made the lower links pretty steep at ride height. We wanted about 7 degrees of angle at ride height, so we then rolled the axle mount up so it was just below center on the tube.

With the lower links mounted higher but still not too steep, we realized that the separation at the frame end of the links was pretty close. We wanted at least 4 inches for flat links to better transfer the forward drive power of the axles, but only had 21⁄2 inches of separation between the centers of the rod ends. To raise them on a normal TJ would be a problem, as they would hit the tub, but since our Jeep is going to be a truck we felt we could move them up above the framerails. First we had to cut off the L-bracket of the mount.

We welded on the lower link frame mounts with the bolt for the FK rod end running vertically. We would usually run that bolt horizontally if possible for optimal movement of the joint and strength, but the joint doesn’t bind with our suspension so it should be fine. Plus, we were able to reuse the lower link mounts rather than make new ones. The upper frame mount now just protrudes 11⁄2 inches down the inside of the frame.

At ride height the upper links slope downward 1 degree and the lowers up at 7 degrees, which is pretty good, but those upper frame mounts need to be tied into the frame more. We added a top plate to the frame and planned on a crossmember between the mounts, but are worried it will hit the driveshaft at full compression. We are planning on tying the mounts into the roll bar and rock sliders, which will strengthen them immensely.

The crew at Randy Ellis Design had made gussets for a customer with a long-wheelbase TJ truck conversion, and when we saw them we had them send us a set for our project. We mounted these gussets to help stiffen the frame since it is so long and not very tall. These were tied into the upper frame link mounts as well for strength. More gusseting will occur when we get to building the roll bar or cage.

We replaced the factory coil springs with a set of heavy-load Old Man Emu 21⁄2-inch coils. We want the Jeep truck to as sit low as possible but still fit 37s. The coils make the frame sit taller than we planned, but we don’t have the weight of the cab, fuel, tools, spare tire, driver, passenger, dog, cooler, dog food, camping gear, other cooler, and other stuff on them, so we’re banking they will settle down to our desired 61⁄2 inches of uptravel. Swapping coils is an easy fix if needed, as OME has a variety of weight ratings for heavy or light Jeep TJs. We can also adjust pinion angle by lengthening or shortening the 7075 aluminum links.

We pulled the coils out of the suspension and dropped the frame back onto the spring perches to measure for shocks. We are running Old Man Emu Nitrocharger shocks in the stock location. We compressed them completely and measured their length eye to eye at 131⁄2 inches. This will be where they end up at full compression, so we tacked the lower shock mounts on at this length.

We double-checked all our measurements, cycled the suspension throughout its travel, and verified that the links were not contacting the frame. This is why you want to tack-weld all brackets first. We made sure the axle was centered and the pinion pointed at the rear transfer case output since we are planning a CV rear driveshaft. Then we burned all the brackets into place.

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4-Link A 14 Bolt Axle - 4-Wheel & Off-Road Magazine

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