1971 Caterpillar 120 Grader

[chucky]

Recently purchased in less than operating condition. Has a military specific serial number different prefix versus civilian model. Being i work for Caterpillar I have access to most anything information wise. We have a guide that converts military to civilian in most cases it is correct. The machine serial number is 90R00137, guide states a 13U civilian is equivalent, close but needing help. No M designation on the US Army data plate. No luck in searching for publications online. Anyone have a book stashed or the number for the publication?

What your describing is a model 12 grader called them knuckle buster all the control levers seemed /felt like you were engaging a gear driven control instead of more modern all hydraulic controls . I was around them years ago but ours didnt have a PONY motor to start them but were electric starter our cat d8 cable blade had the pony motors and had the cup with spring loaded lid you put your either ball in on the intake. Try finding an either ball today. I would just treat it as a 12 for repair the numbers on the cat graders ment how long the molboard (blade) was 12 12ft a 120 is 120 inches long all the way up to 26 and yea 26 ft wide blade a monster

 

[chucky]

The key to survival with a #12 is lotsa grease. There are something like 45 grease points in front of the windshield alone. Neglect then at your own peril.

What your describing is a model 12 grader called them knuckle buster all the control levers seemed /felt like you were engaging a gear driven control instead of more modern all hydraulic controls . I was around them years ago but ours didnt have a PONY motor to start them but were electric starter our cat d8 cable blade had the pony motors and had the cup with spring loaded lid you put your either ball in on the intake. Try finding an either ball today. I would just treat it as a 12 for repair the numbers on the cat graders ment how long the molboard (blade) was 12 12ft a 120 is 120 inches long all the way up to 26 and yea 26 ft wide blade a monster

Once you get her up and running and decide to ROAD it (drive it) on the street to another location make sure ahead of time to know how to lean the front wheels or you will never make your turns onto other streets without leaning the wheels.

 

[garp]

And finally got the engine done and loaded. Hopefully this coming weekend get it fired up and under its own power.

got the engine in. transmission serviced and fired it up. No hydraulics. Found shaft splines worn off. So more parts coming. was really happy the transmission filter and screens were super clean.

hydraulics only used for steering assist, moldboard sideshift and parking brake. i guess they just Armstronged it after the splines gave out.

 

[garp]

What your describing is a model 12 grader called them knuckle buster all the control levers seemed /felt like you were engaging a gear driven control instead of more modern all hydraulic controls . I was around them years ago but ours didnt have a PONY motor to start them but were electric starter our cat d8 cable blade had the pony motors and had the cup with spring loaded lid you put your either ball in on the intake. Try finding an either ball today. I would just treat it as a 12 for repair the numbers on the cat graders ment how long the molboard (blade) was 12 12ft a 120 is 120 inches long all the way up to 26 and yea 26 ft wide blade a monster

it is a model 120.