It seems that everywhere you look people are swapping the Ford 8.8 rear axle under other vehicles. You can't log on to any forum on the Internet without seeing at least three topics on the front page asking about this stout little axle. It is becoming an increasingly popular swap, especially for Jeep guys and gals looking to replace their stock Dana 35s with stouter equipment. The 8.8 is a great solution because of its comparable width and similar bolt pattern to the Dana 35 found in Jeeps.
This kit comes complete with everything you will need to do the installation. The kit contains the new shafts, the C-clip housing end adapters, new bearings and retainers, and all the hardware you will need to bolt up the kit. The bearings included in the kit are commonly used by custom axle manufacturers on Dana 60s and other 35-spline axle applications.
However, the stock 8.8 axle found in most Ford Explorers does have a few downfalls. Things like C-clip axle retention and a narrow 59.5-inch width measurement are oft-cited weaknesses. Even with these problems, many people are scouring the junkyards for derelict Explorers to swipe these axles from and transplant them into their own rigs. That's why Superior Axle & Gear decided it was high time somebody addressed these axles' weaknesses. After a few months of research, the folks at Superior developed an axle upgrade kit that fixes the 8.8's shortcomings and converts it into one stout axle that should easily cope with 37s and a heavy right foot. This kit eliminates the C-clip axle retention, works with any locker currently available for the 8.8, and adds over an inch and a half to the width of the axle! This alone sounds like a great idea, but the guys at Superior took it one step further and produced a kit that can be installed in your driveway with no more than some basic wrenches, a hacksaw, and a file in just about an hour. When we first got wind of this Super 88 kit we knew we had to try it out for ourselves. The axleshafts that come in the kit are a one-piece forging made in the U.S.A. from American steel. The 31-spline, 4340 chromoly shafts are CNC-machined, rolled-splined, and induction-hardened for added durability. Also, the larger, thicker flanges will not bend like the stock pieces do. The wheel-stud holes are drilled and tapped for 1/2-inch thread in wheel studs in both the stock 5-on-4.5 and 5-on-5 bolt patterns.
To prove that this is indeed a driveway-installable kit, we installed one on our own front pad. The Super 88 kit will be available from Superior Axle & Gear and its distributors by the time you read this with an MSRP of about $540.
To begin installing this kit, you need to remove the dreaded C-clip retainer inside the differential, which means draining the oil and pulling the cover. With this done, pull the tire and wheels after placing the axle on jackstands. Remove the old axleshafts, and unbolt the brake components from the housing ends. | 
Axle seals and roller bearings need to be removed from the ends of the axletubes for the new kit to be installed. The seal is easily popped out, but the bearing can be a bear. If you don't have an internal three-prong slide hammer, a chisel or punch can be used to remove the inner race and bearings, and then the outer race can be chiseled in half and removed. | 
The outer stub ends of the axletubes need to be cut down flush with the shoulder protruding from the axle end flange which holds the brakes. This step is critical to ensure a good, leak-free seal. We used a big cut-off wheel, but a hacksaw can be used as well. |
A small lip is left in place on the end of the tube where the welded bracket is, but it must be ground smoothly and squarely with a grinder, although a file can be used if you have the time. The inside edge or the bearing bore also needs to be deburred, and the brake plate needs to be reamed a bit on the inside diameter to ensure that the new axle bearing slides through it easily. | 
The C-clip eliminator plates are precision machined to fit perfectly inside the axletube to keep the new ends square and concentric with the tube. The back of the plate has a recess that fits over the axletube, while the indexing ring fits inside the tube. RTV silicone is slathered on the back side before installation to keep oil in and water out. | 
It is critical that this end plate be bolted on squarely, and not beat onto the housing with a framing hammer. Superior supplies longer bolts and extra large nuts to squeeze-press the plates into the tube a small bit at a time from each bolt. After the plates have been pressed on, the brake caliper and dustshield can be reassembled onto the new tube ends. It may be necessary to grind the lip of the dustshield down so that the bearing will go through easily. |
The shafts are 4340 chromoly with 31 splines and a large axle bearing found on 35-spline custom Dana 60 axles. The big bearing indexes into the new end flange and has more than twice the capacity of the stock roller bearing. The bearings and seals come pressed onto the axleshafts, so you don't need a press or a machine shop to help you. | 
The wheel-stud holes are drilled and tapped for 1/2-inch thread-in-style wheel studs in both the stock 5-on-4.5 and 5-on-5 bolt patterns. Make sure you pick the right pattern, then apply some thread locker and zip them home. | 
The final install is a breeze. The brake assembly is slipped onto the new flange and bolts, then the axleshafts are installed. The retaining flange on the axle is bolted to specs, and the rotor, caliper, and tires are installed. Make sure you fill up the diff with fresh oil, and your driveway install is a done deal. |