Hd5b steering

This is from my manual. The drain plugs are on the bottom of the casting directly beneath the steering clutches. They are either 5/8" or 3/4" pipe thread.
The brake adjusting nut covers are under the seat.

On the bottom of the clutch housing (underneath the machine) is where the plugs are to be installed for filling the housings with solvent.  On my HD5 they use the same plugs as what you remove on the drawbar mounts for checking the final drive oil level.  It is simplest to remove the metal cover over the steering clutch to fill.  The link is to a picture of the clutch cover under the seat/fuel tank.

Hey guys,
Just joined the forum while reminiscing and your post took me down memory lane. My uncle was an All is Chalmers fanatic. I remember as a kid he bought two machine from out west someplace. Bought one and they threw in the second..... One I remember operating had a block on top of the blade and two stacks . The one thrown in was an HD 21, that I remember as it was used more. Had two HD 5's one dozed one excavator. Two either 22A's or 922 A's ? A bunch of dump trucks B series Mack's ( Wished I had them ) Thanks for the memories.

Filling the housing through the adjuster cover on each steering clutch housing after installiong the 3/4" pipe plug in lower case drain - has worked in the past - just do not put a heavy load on machine until after the clutch discs have had a chance to dry . 
 Also in might be best to remove the full brake housing cover as the throw out bearings need to be lubricated - the felt wick oil system from the ring and pinion case isn't the best at oiling that bearing and the update to grease should be done by adding a hose and zerk to grease from outside of case