8.8-Inch Ford-to-TJ Rear Axle Conversion
Out of-the-box the ’97-’06 Jeep Wrangler TJ is an extremely well-performing off-road machine. Add a small lift, lockers, and knobby tires and it will take you far. Unfortunately, many of the open-top wheelers have a ticking time bomb of a rear axle, known as the Dana 35. In the stock configuration the 71⁄2-inch ring gear and 28-spline C-clip axleshafts on the Dana 35 are adequate at best. When you add big tires and tough terrain into the mix the light-duty diff just can’t keep up. So what’s a wheeler to do?
We understand that not everyone can drop the coin on a super-high-zoot aftermarket rear axle, so instead of heading to the bank we suggest heading to the boneyard. Dollar for dollar the 8.8-inch rear axle found under the rear of most Ford Explorers is one of the cheapest and toughest axles you can put under the rear of your Jeep. These junkyard jewels are already fitted with disc brakes (’95 and newer), the same 5-on-41⁄2 wheel bolt pattern, 31-spline axleshafts, and an 8.8-inch low-pinion gearset. On top of having stronger internals, the 8.8 housing is designed to carry more weight than the Dana 35. This makes it great for holding up the lightweight TJ platform, and when used with restraint it can live a long life turning up to a 37-inch-tall tire.
To find out what it takes to put one of these junkyard jewels into the back of a Wrangler, we took a trip to the gear and 8.8 experts at East Coast Gear Supply in Raleigh, North Carolina. East Coast Gear Supply specializes in the 8.8 conversion for XJ, TJ, and YJ Jeeps and has years of drivetrain experience. In addition to selling complete bolt-in axles, ECGS offers a host of in-house axle brackets, brake, and yoke parts for the DIY 8.8 axle builder. For more information check them out on the web at www.eastcoastgearsupply.com.
While the 8.8 swap may seem a little labor intensive, it’s definitely something you could knock out over the weekend with the proper skills and tools. The factory Dana 35 TJ rear axle is roughly an inch wider than the 8.8. Most Wranglers running aftermarket wheels with around 31⁄2 inches of backspacing should be fine. Rigs with factory wheels or less wheel offset should plan on running a set of wheel spacers.
Another item to note is that the yoke offset on the 8.8 is 2.75 compared to the Dana 35’s 0.75. This means your driveline will be slightly angled. For those equipped with a slip-yoke eliminator and CV driveline this will not be noticeable. If your Jeep is still fitted with the factory driveline and slip-shaft you will likely encounter a driveline vibration.