Reading the forums and discussing with others has led me to believe there are 2 common mechanical component failures that seem to be happening to Toyota FJ Cruiser off road. The first is a blown CV or Birfield Joint in the front drive axle and the second is a broken tie-rod. Both of these failures are related to more aggressive off road activities.  There has been some talk about and parts available to strengthen these, however, you should consider the forces involved in four wheeling and why a failure happens.

These components break when the forces on them become too great. If you replace these parts with stronger components where will the stresses go? Further into the system. Next in line for the tie-rods is the steering rack. The rack is an expensive component and would be a very difficult trail side repair. For the Half Axle the next component in line could be the front differential, the drive shaft or even the transfer case. Being unsure of what the next weakest component would be I prefer to keep the weak link the half axle.

People in the off road community call these mechanical fuses. A fuse is put in line with other components to blow when the energy demand become too great so as to prevent the other components from failing. A fuse tends to be the easiest part to replace.  So it is with the case of these two “mechanical fuses”.

Half Axle Failures

CV Joints tend to get blown when the front wheels are being spun while attempting to climb an obstacle. What tends to happen is the front wheels are hopping around and one wheel will start to spin at a high rate of speed (the driver is causing this my trying to gain traction by spinning the tires). If the vehicle moves and the spinning tire suddenly finds traction all the torque of the tire being stopped is taken up by the drive shaft. The weak link here is the CV joint. If the force is to too great the CV joint will self destruct or blow up. At this point the drive for one of the front tires is gone.

Once you have this failure your FJ can not be driven in its current condition. There are 2 field solutions to this problem.

The first solution is to fully disconnect the broken drive axle from the front the wheel. I would leave the CV housing and shaft into the front differential in place. I would then disconnect the drive shaft from the transfer case to the front differential. This will convert the FJ into a 2 wheel drive that can still be run in low and with the rear locker engaged. This is an emergency recovery fix and the FJ should be gently driven to where it can be recovered and taken for repairs.

The second solution offers a more permanent fix. A trail side repair can be performed to replace the complete half axle. To affect this you must have a spare half axle assembly available. I carry a low cost aftermarket replacement. The half axle is the same as the late model 4 Runners. With the correct tools and training this repair can be made in less than 3 hours. Once completed the FJ is ready to continue your trip. I plan on practicing this repair in my driveway so I will know what I am doing should I need to perform it in the middle of the woods.

Tie-Rod Failures

Tie Rod Failure - Photo by Sandstormer

This is an easy trail side fix as long as you have the part on hand. I carry the full tie-rod assembly with new clips

In summary, these are 2 common failures to the FJ Cruiser that can both be remedied as a trail side repair. This will both save you the cost of a remote tow or repair and also may allow you to finish your trip.