Repair of Air Lockers on Unimog 1300L

The front lockers on the 1300L did not always work as they should and since I am putting it up for sale it was necessary to replace the O-rings on the air lockers. The first thing to do it to support the frame of the unimog, support the axle and remove the tire.

On the front the tie rod,stablizer, the two brake lines at the differential,the shock and spring have to be removed.


The air line to the axle has to be removed. The differential bolts together so after everything else is disconnected the differential is seperated and if you have the axle on a dolly it is pretty easy to roll the axle out. It is pretty heavy so a dolly makes the project alot easier.

You can see above that the rotor is sitting on some blocks. This is a little unstable so on the rear we used two jack stands. The problem here is that the air locker is on the short side of the axle (driver side). We took of the wrong side but the other side is the same process.

You can see the cogs behind the spring. The piston is behind it. When the lockers are engaged the cogs are pushed foward and engage its conterpart in the differential (next picture). When the air is released the the spring disengages the locker.

The other part of the cogs that lock the axle in the diff.

This is the piston that pushed the cogs to engage. At the top is an o-ring. There is another o-ring in the axle tube. You can see a little rust on the sliding part of the piston. That was cleaned off with emory cloth.

Here is a picture of the differential with the guts out of it.

Doing the rear is the same as the front except you have to deal with the rear stablizer and the emergency brake. Pretty straight foward just have to take it off. You note that there are two axle stands that works pretty good. Puttting it back together is just a reverse from taking it apart. We used a couple of mog jacks that helped in lining everything up when getting the axle splines back into the differential. Other that it being heavy it was pretty straight foward. A dolly under it makes things much easier and having a friend help is pretty helpful. When the job was done the lockers worked great. The o-rings are about $5 per axle it is the labor that takes the time.

home page