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Hitachi EX 120

Johnny Utah

Member
Joined
Dec 2, 2008
Messages
13
Location
Belfast Northern Ireland
Hello,

I am asking to some help regarding Hitachi EX120 machines, I am new to tracked excavators and have only driven and owned backhoe machines and have little experience with track machines. I understand that a USA spec may differ from UK spec but what should I be looking out for on these machines I understand about undercarriage wear and what not but havent got much basis for judging how worn slew rings etc are.

I viewed a machine yesterday and there a very slight rock on the turntable which I could feel while operating, should I walk away from the machine, I'll try to attatch a picture, the machine is a 1996 EX 120digger12.jpg

Any advice would be greatly appreciated

Thanks

Chris
 

JackDeere

Active Member
Joined
Apr 10, 2008
Messages
38
Location
California
Utah
You don't mention how many hours are on the machine. If you can feel the play in the swing bearing it is really bad. Anything over 3.05mm of play is bad. To check the play in the bearing you need to attach a dial indicator with a magnetic base to the carbody with the indicator touching the outer part of the bearing bolted to the upperstructure. It takes two people, one operating machine and the other to read the gauge. It can be misleading judging the play by sitting in the seat and rocking the machine.
 

roddyo

Senior Member
Joined
Mar 24, 2008
Messages
788
Location
Arkansas
Occupation
Manipulator of the Planet
Rocking Turn Table

Hello,

I am asking to some help regarding Hitachi EX120 machines, I am new to tracked excavators and have only driven and owned backhoe machines and have little experience with track machines. I understand that a USA spec may differ from UK spec but what should I be looking out for on these machines I understand about undercarriage wear and what not but havent got much basis for judging how worn slew rings etc are.

I viewed a machine yesterday and there a very slight rock on the turntable which I could feel while operating, should I walk away from the machine, I'll try to attatch a picture, the machine is a 1996 EX 120View attachment 28177

Any advice would be greatly appreciated

Thanks

Chris

Don't walk away, RUN!!!:D
 

Johnny Utah

Member
Joined
Dec 2, 2008
Messages
13
Location
Belfast Northern Ireland
Utah
You don't mention how many hours are on the machine. If you can feel the play in the swing bearing it is really bad. Anything over 3.05mm of play is bad. To check the play in the bearing you need to attach a dial indicator with a magnetic base to the carbody with the indicator touching the outer part of the bearing bolted to the upperstructure. It takes two people, one operating machine and the other to read the gauge. It can be misleading judging the play by sitting in the seat and rocking the machine.


They claim there is 5600 Hrs on this 96 machine, I know it is hard to judge the rocking but i would say there is more that 3mm of rocking I have had a look at the turn table while my father was rocking the machine and vice versa I think it would be best to leave it.

Thanks for the reply
 

cps

Senior Member
Joined
Jul 13, 2008
Messages
811
Location
Ireland
Occupation
plant mechanic
Hi there Johny, Im from N.Ireland to, im a plant fitter and wouldnt mind have a quick look for you if you d like?
 

John C.

Senior Member
Joined
Jun 11, 2007
Messages
12,870
Location
Northwest
Occupation
Machinery & Equipment Appraiser
Were you rocking it side to side or up and down by pushing the bucket into the ground.

Up and down play on a new bearing is about 0.030 to 0.040 inch. Anything close to 0.100 inch up and down is junk.
 

ncbschzzt

Well-Known Member
Joined
Jun 10, 2008
Messages
192
Location
U.S.
Occupation
john deere/hitachi field tech
not junk

It all depends on your price, a worn swing bearing is not that big of a deal. A good tech can fix her up in no more than two days. But if you don't want to put money in her you best be walking. Just remember in about 95% of used machines like this, you will be buying something in the first 100hrs. There is no way around it, so just be aware.
 
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