JD 950 upper lift arm not lifting on right side

[dtl6787]

Hello,
I have a mid-'80s JD 950 that I'm having a lift arm issue with. The left side arm lifts properly , but the right side arm will not lift, resulting in a lop sided cutter.
With the cutter disconnected from the arms, (no weight on arms), the right side arm will lift properly and all the way up like the left side, it just won't work with weight on it.
The right rear quick connect fitting is leaking some, not a steady stream, but a steady drip and I was wondering if this leak would be enough to prevent the right side from working? I am keeping hydraulic fluid level full.
Any ideas on a fix for this problem would be appreciated,
Thank you,
Dan

 

[dtl6787]

Hi,
Thanks for the reply, I did pull the arm and checked the splines, they appeared to be OK, no obvious damage and no clicking or other noise when trying to raise. I have access to another 950 in a local tractor salvage yard, so I may get the arm off that one just to be sure, if it checks out undamaged.

 

[dtl6787]

Yeah that shaft appears to be pretty stout, but I'll check it out. The tractor is at a different location, so it will be a couple weeks before I can get back up there, but would like to have items to check off as possible causes.

 

[dtl6787]

I wonder if a leaking O-ring(s) would cause the problem? But with one piston running both sides, it seems likely it would affect both arms.
Thanks for the diagram, I have a shop manual on the way.

 

[oldtimer 66]

I think K7LN has identified the problem. Try to rotate the right arm with maybe a large adjustable wrench and cheater. If it moves independently of the left arm then the shaft Pt 35 is probably broken. This may take some large force to do this. This follows your previous right side inspection of the Pt 29 splines.

 

[dtl6787]

Thanks for the response. I'll definitely check it out.

 

[dtl6787]

The problem with the tractor lifting the mower on just one side was a cracked upper lift arm, about 1/8" wide all the way across. With the weight of the of the mower it would separate enough so it wouldn't lift. With no weight it would lift. Found one in the tractor junkyard, installed Saturday and it works great.
Thanks for the replies, they got me looking around the shaft area for a mechanical issue, rather than a hydraulic one.