The original posting of this article is here on 4WD&SU Magazines website: http://www.4wdandsportutility.com/tech/0810_4wdweb_2005_nissan_xterra_air_locker/index.html
Horsepower is nothing without traction, which is why many Nissan Titan, Frontier and Xterra owners have been waiting for a new locker option. The M226 is a variant of the Dana 44 and buying your truck from Nissan fitted with the e-locker has been the only way to get a manually activated locker. If you have been in search of a locker for your Titan, Xterra or Frontier, you may be in luck. The Xterras and Frontiers with the Off-Road package came with an e-locked M226 rear end. Those with a manual transmission also have the M226 rear end, but it's has nothing but an open carrier. The ring gear was also transferred from the stock carrier to the ARB air locker.
A few weeks ago I got a call from ARB's marketing department letting me know about their new M226 air locker, one of which was flown in early from Australia and they wanted to know if Rugged Rocks Off Road would be willing to help them out with the first M226 Locker install in North America and let them know how it goes making note of anything special that had to be done. Of course I jumped on this opportunity right away. Being that I didn't have an Xterra myself to do this install on, I extended this opportunity and called Jesse Feng, an owner of an '05 Xterra S 4x4. I met Jesse through the Rugged Rocks forum, he had been wheeling with a few of the other guys on the forum and judging by the pictures he had posted of his rig on the trail along with the body damage, a bashed in muffler, scuffed up sliders, dented rear bumper, scraped up rear diff, bent trailer hitch and scarred up leaf shackles; I decided that lack of traction was the only thing holding this guy back on the trail and could really benefit from the new ARB M226 Air Locker. We arranged to get the locker installed by Scott, the owner of Sterling Autosport in Murrieta, CA. Scott is a seasoned wheeler that has been setting up gears and ARB air lockers for quite some time. I figured he wouldn't have any trouble getting this new locker installed into Jesse's '05 Xterra. Once we arrived Scott had the Xterra on the lift in the shop with the wheels off and was pulling the diff cover in no time. After draining all the diff oil we quickly realized that the spider gears were pretty hammered and worn which was a shock being that there is only 37K miles on this truck.Once the oil was drained, the 4 nuts holding each axle in was removed, and the axle shafts were pulled out.The bearing caps were then unbolted and the carrier was removed giving us first look at the unexpectedly large pinion gear. Once the carrier was removed, using a puller, the carrier bearings were pulled off the stock carrier and pressed onto the new ARB air locker. The ring gear was also transferred from the stock carrier to the ARB air locker. Once the carrier was removed, using a puller, the carrier bearings were pulled off the stock carrier and pressed onto the new ARB air locker.
The old silicon that sealed the cover the housing was removed and a hole for the air line was drilled and tapped in the differential housing.The housing was cleaned out ensuring that there were no metal particles from drilling left in the housing. Once the air locker was assembled with the bearings, the ring gear and the copper air line attached, Scott loaded it into the differential housing. You may notice that the M226 uses cages on each side of the locker instead of using shims to set up the gears which makes things easier, Scott had the gears set up in no time. Since Jesse wheels fairly hard, Scott set up the gears a little tighter than normal to help keep teeth from breaking when under load. The copper air line was then routed up and over the ring gear, making sure it wasn't touching any moving parts and attaching it to the proper air fittings. The freshly painted differential cover was then bolted back to the housing sealing it up with silicon. Replacing the wheel bearings and seals is strongly recommended, if these are not replaced there is a very strong chance they will leak. Usually this isn't a problem with other axles but the M226 seems to be very touchy.
Once the new bearings and seals are in place and the axle shafts are bolted back into the axle, the diff was filled with oil. The tires were then back on and the Xterra was back on the ground. Scott then took the Xterra for a test drive before turning the keys back over to Jesse.Mounting the air compressor wasn't too much of a problem, There was enough space to mount it behind the drivers side headlight but would have been difficult to mount so we opted to mount it to the fuse box. Usually I wouldn't advise this but this spot keeps the compressor up and away from the elements.
It was mounted onto the fuse box right as close to the strong corners as possible. We also used the large square backing plate to keep the screws from pulling through the box. When the holes were drilled, we were careful to not drill through any of the diagrams on the underside of the fuse box lid incase we needed to reference it in the future. We then ran the wiring loom across to the driver side and through the firewall securing it with zip-ties along the way. There is also a ground wire that needs to be connected to a solid ground, we used a nearby screw in the body. There is a large cluster of wires going through the firewall on the drivers side just below the windshield. This large cluster of wires has a large grommet that has plenty of room to poke another hole in it to pass the compressor wires through. The easiest way to do this is to tape the wires to a piece of wire coat hanger and poke the hole in the grommet pulling the wire coat hanger through along with the wires. The wires will come out above and to the left of the pedals in the floor.
The wires were un-taped from the hanger and routed behind the plastic kick panel up to where the two blank switch spots are on the left of the steering wheel. Once the blank switches were removed, the wires were fed through the switch holes and connected to the provided switches by following the color coded diagram provided by ARB. At this point you only have 2 wires left, the power wire and the dimmer light wire.The power wire was extended and was taped into the red wire to the 12V outlet in the dash.
The dash was disassembled by removing the try from the top of the dash, removing the one screw that is now exposed and pulling straight out on the entire panel. The dimmer light wire was tapped into the red dimmer light wire from the lose plug under the dash right next to the mirror adjustment plug.
All that is left at this point is the air line from the compressor to the locker. We started under the hood at the compressor and ran the line down the firewall keeping it away from the engine as much as possible. The air line was then run along the top, outside of the frame where we were able to zip tie it to some wires that were running in the same direction. At the rear of the Xterra the ABS line was followed untill the brake line was reached which was followed the rest of the way to the differential and was terminated at the fitting on the differential housing. Once the air line was ran, we hit a local trail for some testing and everything worked perfect. See you on the trail!