Does anyone know where I can purchase a REAR AXEL for a Maxxam 150 2R? I have not had any luck searching for it.

Maxxam was the less expensive version of the Carter brand. Neither are in business, so you will need to try and match yours up with a Roketa or Hammerhead. You will need the following:

Diameter and spline count of the ends
Diameter and spacing of the bearing hangers
Spacing of sprocket and brake mounts

https://gokart.maximum.parts or BuggyDepot.com might be two places to check once you have dimensions.

Thank you!

Those axles are harder to find now. Since the machine is not in production anymore, parts changed and they do not manufacture those axles anymore. I ordered a bunch when they switched the model but ran out.

It doesn't mean nobody still have some!

As PGH said, you will have to check the measurement and all info. 2 models of axles has been use over the years. It will depend on your swing arm.