[UberXY]

So you just went around a corner onto a gravel road and 3 lights lit up on your dash. Bad, but the good news is that it is a free or $10 fix you can do in two hours with few skills. A gear in the AWD servo has worn out.

The servo is attached to the diff on the left side of the car, pretty much under the pedal area for a US car. First you need to undo one bolt on the heat shield and peel it back a little. Then remove the four Torx bolts securing the servo to the diff. Access to the bolts is slightly limited but not too bad. Unclip two electrical plugs and you are ready to put the unit on the workbench.

Separate the motor assembly from the little gear box. You will see that the innards of the gear box seem to be protected by a sealing plate. It’s just peened on, so worry it a little on the corners with a little screw driver or a dental pick thingie and it will pop off.

Inside you will see a nylonish flat gear. Teeth will be worn out on about a quarter of the diameter of the gear. You can either remove the gear, rotate it 180 degrees, and replace it so that unused teeth can now mesh, or you can buy a new one on eBay for $10.

Reassembly is the reverse of disassembly. You do not have to mess with the computer.

I suspect your dealer or indie will want about $650 for a new unit and maybe $300 for labor, if you are lucky.

There is a decent YouTube video out there.

[nikewolf33]

I just did this on my x3 e38 I replace the servo gear with a all metal one and change the transfer case oil as well and still have the 4x4 light on. idk know what it could be I need help