What I have learned about my Nissan Xterra Stock R180A

The Nissan Xterra R180A (often referred to as the R180) is the front carrier assembly or differential case. The R180A is shared between the 2005-2015 Nissan Xterra, 2004+ Nissan Frontier, 2005-2012 Nissan Pathfinder, and the 2008-2012 Suzuki Equator. The stock gearing comes in 3.13, 3.36, 3.54 and 3.69. There are also aftermarket 4.10 gears available from some vendors (note: the 4.10 gears are compatible with the 3.54 and down carriers)

There have been a number of consumers having issues with the spider gears breaking or stripping. In some circumstances, this will crack or punch a hole in the differential itself. I was lucky enough that my differential stayed intact. My gears did strip and leave some good chunks and a metallic slurry in the gear oil.

a metallic slurry in the gear oil

Spider gears

The general consensus as to why this happens is wheel spin and then gaining sudden traction. Trying to get out of snow banks, loose gravel, or offroad trails seem to be common themes. I am not 100% when it happened to me, but since I am on offroad trails as often as I can be, I assume it was somewhere out there.

offroad trails as often as I can be

Since I was out of warranty and not ready to Titan swap (mostly due to funding), I opted to put in a Lokka locker instead of replacing the stock one. This replaced the spider gears without having to fix anything else. Easily the best $300 I spent on the truck. There are some concerns driving the locked front differential in the snow. However, I think the gains are worth the snow hassle. And in my opinion, the snow really isn't a problem as long as you drive it below 40 mph. It will go above 40 mph but the steering becomes quirky. It will be very, very hard to become stuck!

Lokka installed

The lokka has quite a few benefits on the install side of the equation too. Most owners that are mechanically inclined and have the right tools can install it themselves. You may need shims to get it in spec. Apparently these shims (http://amzn.to/2kKVQv8) at amazon work. Mine was in spec with the stock shims. The hardest part of the whole install was getting the differential case out of the truck.