It was around April of last year when I first heard of the concept of a full floating rear end. A guy from our local parts store had just returned from SEMA with all sorts of pictures of new and upcoming products. The product that really caught my eye was that of a full floating rear axle for a Jeep Wrangler. After the concept of a full-floating rear end was explained, I thought "God, it would be nice if someone made that for a Samurai!" Little did I know, but the Spidertrax gods had the answer to my prayers already in the works. A few short weeks after my order was placed, the beefiest Suzuki rear end available for a Samurai arrived from NJ ready to be bolted on.

What'as a Full Floater

To best understand the workings of a full floating rear axle, I find it easiest think of a front axle, but without the steering. The advantages that come with a full floating axle also help in understanding it. First things first, let me say that this type of axle should have come on a Samurai from the factory. That would have given the Samurai four-wheel disk brakes, which are both awesome for off-road performance and for on-a-dime stopping ability on the road. The rear wheel bearings would have been as big and as beefy as the front wheel bearings while lasting just as long. For the many Samurais that once were towed behind campers or are now towed to the trail, the un-lockable rear hubs would have eliminated the need for removing the rear drive shaft and removed all the added driveline wear. A full floating rear axle would have meant that the rear brakes did not need to be bled after doing rear axle work. And last, but not least, the rear wheels would sit with the vehicle'as weight on spindles and not on the half-shafts, meaning the half shafts would have dealt with less overall stresses. Because of cost, Suzuki, like most manufacturers, is stuck with building standard axles. After all, from the dealer, a 1986 Suzuki Samurai only cost around $6,000. That price would have been much higher if a full floating axle came stock.

Now, almost fifteen years after the Samurai first made its debut in the US, it is possible to have all the above benefits by a simple installation of a full floating rear axle that uses Suzuki OEM parts and a pair of custom half-shafts.

The Full Floating Axle was designed and manufactured by the geniuses at Spidertrax. It is important to understand that this is not a kit, but an actual axle, ready to be installed under a Suzuki Samurai with the addition of some other stock Samurai parts. The axle can be custom made to any width and has many options, including welded trussing and locker installation. The axle is made to order and arrives in about a month via UPS. As with all of Spidertrax'as products, there are detailed instructions included (and also available online). The order form is also available at their web site and it is a very interesting and informative read.

History

Eddie Casanueva and Tom Kingston are the co-founders of Spidertrax. They both brought up the concept of a rear full floating axle to each other at the same time.

"Originally, this was going to be a kit with weldable components to modify a OEM Samurai rear axle. However, through this initial design, we saw many drawbacks to this setup," Tom told me. "In addition, there were some problems with this setup that were tough to deal with. We were at the point of scrapping the entire idea until we realized that we had the ability and the machinery to build a complete rear axle housing. That is when the Full Floater Axle (not Full Floater Kit) was born."

I believe Tom and Eddie must be very proud of their design and rightfully so. It is quite a work of art. Eddie built the first axle to go under his rig and while the design was essentially complete, "building one was the final design test."

"We needed to be sure that our manufacturing strategy for this product would be feasible in the long run. The result... a Samurai rear axle that went together easily and worked flawlessly."

Both Spidertrax vehicles now run this setup. Eddie'as has every option. Tom'as has all but the trussing.

I asked what the hardest part of the designing and manufacturing was. Apparently cost was one of the most challenging goals for this product. They wanted to manufacture and sell the basic Full Floater for less then $1000 and they reached that goal.

As for production, everything went smoothly till they hit a snag with the trussing option. Welding the axle trussing creates a lot of heat and the axle gets very hot. After pulling a completed axle from the assemble line that was almost ready to be shipped to a customer, they noted in the final measurements that the axle had warped from that heat. So this brought around the design of a new jig for welding the axle trussing in place that would adequately draw heat away during welding and keep the axle from warping. Kudos and extra credit to them for catching that axle before it was shipped to anyone: a sign of good quality control.

Getting Started

To complete the full floater sent by Spidertrax, several stock Suzuki items must be on hand. The best way to acquire these parts would be by purchasing an entire front Samurai axle, minus the third member. While the Birfields from the front axle are nice to have as extras, it'as the brake and wheel assembly that are needed to complete the full floating rear axle. From the front of a Samurai axle you will need: the two wheel spindles; two sets of wheel bearings with their retaining washers and the four nuts; two disk brakes; both caliper to axle mounts; two brake calipers with the rubber brake line still attached; and a set of locking hubs. Basically that is everything from the backing plate to the end of the hub.

Of course the brake disks should be resurfaced, and the spindles will need to be sent to Spidertrax to be modified for the new axle. The only other parts needed would be a matching ring and pinion from a Sidekick or Tracker for the front diff of your Samurai and the Spidertrax E-Brake Kit if you still want a functioning e-brake.

Since the differential gearing with the full floating axle is 4.63 or lower, the front differential of your Samurai must be changed to match the rear. I called Gary Munck at Petroworks Off Road Products, told him what I was doing and he knew exactly what I needed. Three quick days later, a 4.63 Sidekick ring 'an'a pinion arrived in good order and at a good price. I installed the rebuilt front differential right away because the rear axle was not done yet and I did not want to deal with a lot of down time on my Samurai. If you start your installation like I did, just remember, it is not a good idea to drive in four-wheel drive with stock gearing in back and 4.63'as in front.

What You Get

When an order for this axle is placed, there are several options that can be added. All the axles come with new mounting hardware for the brake calipers, spindles, hubs and differential. Custom Full Floater shafts, new axle seals, a OEM fill and drain plug and the sidekick third member with the ring and pinion are also part of the "Basic Full Floater". What has to be decided is how you want the axle set up. Things to consider:

• Where the shocks are to be mounted
• Where and how the spring pads are to be mounted
• Whether a locker should be added
• Whether brake lines should be attached
• Proportioning valve setup

A nice big bonus is the availability of welded axle trussing.

Impressions

One of the nicest things I noted about having this new rear end, besides it being much stronger, is that it is heavier. I have found, with my lift and 33 inch tires, that the stock rear end was just too light. The stock rear end was great when I was sprung under, but after a SPOA, the rear end was just too light to get any good traction while under heavy articulation. Also, the heavier un-sprung weight has added some more on-road stability for my rig. If stock Samurai'as came with this rear axle, it would have taken Consumer Reports many more attempts to lift tires off the ground instead of the fifty, steering locked, attempts they did.

When I was assembling my new axle, I noted that Spidertrax had left the disk backing plate out of the assembly. Obviously, the stock front backing plate is not a necessity, or it would be there. But because of the off-roading I do I opted to install that backing plate so as to protect my rear disks a little more. While I like having the backing plate on, it does mean a little more work when pulling the half-shafts out. It is a toss up: easier assembly and disassembly or added disk protection from sand, stones and mud.

The new axle comes with new hub mounting bolts. Here it is very important to do two things. The new hub mounting bolts need to use the original tapered hub washers, and they need to be thread locked with some sort of lock-tight. These new bolts use an Allen Key which is nice for getting around the hub to check if they are still tight, but it is harder to set the bolts to the proper torque specifications unless there is an adapter to an Allen key in your tool box. It is very important that all the hub mounting bolts both front and rear are set to the proper torque specifications and that the hub is assembled with those tapered washers. Failing any of these two points leads to the sheering off of the hub bolts.

I also noted that it was easier to check the condition of the rear drive shaft'as u-joints. Unlocking the hubs frees the tension on the drive-line, and leaves the u-joints free for easy inspection.

Hitting the Rubicon

The new axle was installed just in time for the August ASA ORC "Suzukis on the Rocks" Rubicon trip. (LINK) What a perfect proving ground to test the new axle, and what a great trip we had.

The new axle is almost invisible to the user, unless a rear locker is new to the driver. The only other noticeable thing is the new gearing, and oh how nice it was to have 4.63 gears in the differentials. My rig is set up with the 4.63 gears, a GRSII and 33inch tires. On the trail it is very nice to crawl over the rocks. I found myself in second gear a bunch of times, not realizing I could go one gear lower. On the road, this set up is very doable. Fifth gear is now a gear that is completely usable. 70 miles per hour runs the engine at about 4400 rpm. Fine for a 1300, and but reaching the top for a 1600 like mine.

Back to the trail, the most noticeable advantage over stock is the rear disk brakes. The granite slabs on the Rubicon trail were great for testing the brakes. While in 2wd, the rear holds to the slick rocks a whole lot more. I didn'at get that "why are my rear brakes not holding" feeling while descending a steep slope. In four-wheel drive braking goes to all four wheels evenly like a stock set up does, but the transfer-case e-brake is great for holding all four wheels. With lockers front and rear and one wheel on the ground, the t-case e-brake will suffice to hold the vehicle at a standstill.

Climbing out of the granite bowl a half hour into the first day of the Rubicon trip, I decided to take a harder line that went up a group of granite steps. I had a very bad approach line and the front and rear wheels reached the steps at the same time. I did not have enough grip to get up the last of the steps and I was trying to keep the vehicle from hopping around. Backing down to get a better angle was fine. The brakes were very responsive and it was easy to maneuver. Going in for a second try I tried to jockey for a better position between the steps, the slope and the large "gona-roll-you-over" hole. Jessica James, the ASA representative on this trip was at the top of the steps egging me on. My position seemed no better that the first time, but still I was determined. A little gas was applied and then there was a horrendous bang and a clink, clink, clink as my rear u-joint at the pinion gave out and the drive shaft tumbled down the hill.

"Uh-oh'as" and "Oh Darns" from spectators were in the air as I smirked, wondering what I just destroyed. Carefully backing down off the steps and with front wheel drive only, I pulled off to a flat area to check the damage. When the U-joint gave out, it tore out the portion of the yokes that hold the bearing caps to the driveline. While I had forgotten to bring extra drive shafts, Dave King from Asian Auto Parts of Arizona had not, and he gave me a new one to slide in. Having the unlocking rear hubs made for a quick installation of the rear drive shaft. By unlocking the hubs, the pinion flange could be quickly matched to the drive shaft without having to move the whole vehicle. This was a nice feature because I was on less than level ground. From the braking of the u-joint to having the new drive shaft put back on, the whole operation took only five minutes.

The rest of the trip was uneventful for my new rear axle and me, but that is not to say I took it easy. After a day of resting at Spider Lake, I took a spin around the lake trails, driving mostly in 2WD, giving the axle a good workout.

Upon returning to the Tahoe cabin after the trip was over, I noticed that there was differential fluid all over my driver'as rear tire. Without even thinking twice I knew what was wrong, and when I pulled the rear drive shaft out, I proved myself right. The new axle, like the stock axle, has a "bearing collar". On the new axle, the bearing collar does not hold a bearing, but like with the original axle, it is used as a collar for the axle seal. Well, I had not tightened my bearing collar down enough and it had backed off, allowing a bunch of oil to leak out. A word of note to those who get this axle: If you end up getting a leak like I did, check your hub bolts, because the oil will wash out all the lock-tight and cause them to back out.

Overall this is a great axle. I cannot find one thing wrong with it. Maintenance will be easier because of the ease of pulling the half shafts, the reliability of the roller wheel bearings, and the longevity of the disk brakes. The stronger axle housing, third member and half shafts are nice insurance for the future. The hubs make towing easier and decrease the likelihood of being stuck because of axle breakage or driveline failure. All this and more make this axle a must-have addition to the ultimate four-wheeling Samurai.

--Adam Leach