Checking Oil in mack rears

[Walt1967]

Was told today by mechanic that mack rears have 2 to 3 drain plugs or checking points for different parts of rears.is it true that oil from top of rear can leak down and overfill bottom of rear,and you have to drain excess oil every so often. First time having Mack rears so input would be appreciated.they are 44k camels on 91 superliner.

[theakerstwo]

To check the grease level on a mack twin screw remover the plug at the rear of the load housing just below the hold down bolts for the carrier.This is the only level you need to worry about.Keep it full and the top fills its self from the bottom.I have heard many different way of checking but some guys tell you stuff like this not knowing their self.

[wilbur]

The top section only holds so much then runs to the bottom. You only need to check the bottom unless they are both new and dry.

[MACKTRUCKS4]

After the first fill (new or a rear change) check the levels at all fill plugs with the rears warm. It takes time for the gear oil to move to the bottom. If you check it cold, the bottom will be over filled but you can't tell by how much. This is how the mack manuals say how to check them.