One problem related to axle shaft has been reported for the 2007 Toyota FJ Cruiser. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2007 Toyota FJ Cruiser based on all problems reported for the 2007 FJ Cruiser.
I took my fj to have the transmission fluid drained and refilled. They decided to do a complete review although I see no tool makes they told me I need to replace my rear differential, and told me as if they just knew it was an issue. The cost was $2360. I went home and did some very brief research and found that this is a known issue for 2009 and later Fj Cruisers. In 2010 they changed the rear axle. A huge number of owners on the fj cruise forums have pointed out the issue. The cost at the dealer would be to replace it with the same parts that have not been updates and would fail again. Toyota clearly knows the issue and more than likely knew when producing the original fjs. My fj has never been off road and only used for normal commuting. I don't speed or drive poorly, and my driving record is completely clean. I found a good explanation on an axle web site. The 2009 & older Fj Cruisers, 4runners, and prado 120 utilize the 8¿ which dates back to 1979, and was originally used in 3000 lb Mini trucks with 80 horsepower and 27¿ tires. Late model modified Toyotas such as Fj Cruiser run at double the weight, triple the horsepower, and much larger tires to top it off. For this reason there have been lots of failures, enough so that Toyota upgraded the rear to the 8. 2¿ on the 2010 & newer models. It may seem like a small upgrade but there are significant improvements such as beefier casting, larger bearings, larger pinion diameter, larger ring gear diameter, more tooth contact, and a beefier 12 bolt diff case. This makes for an easy swap for your vehicle and will utilize your existing axle shafts, brakes, abs system etc. This is a big safety issue as this could fail at highway speeds.