NX series three-point lift cylinder rebuild? Are the caps welded on?

[MinnesotaEric]

After fixing two major hy-tran leaks last fall and only using my tractor once over an unseasonally no-snow winter, it wasn't until this spring while making slash piles that I noticed that I was going through a few quarts of hy-tran every day and I couldn't find the leak. Well, it turns out that after being exercised, the lefthand three-point lift cylinder leaks like a sieve so my mystery leak has been found.

Moving forward toward leak-free paradise, I looked up the lift cylinder in the parts book for a rebuild kit and there isn't one available. Looking in the service manual, I cannot tell if the cap for opening up the cylinder for service is welded on or not. My local machine shop can find any type of seal in the world so a lack of service parts isn't an issue, but if there isn't a way to open up the cylinder, the machine shop would need to chuck up the cylinder on a laith and cut down the weld, replace the guts and then weld up the cap.

Removing the lift cylinder looks like a bit of a hassle to gain access to the hydraulic line in the back of the lift cylinder, and after doing the Hy-tran service my tractor suddenly will not start (but I haven't begun to look into it other than to look at all the safety switches and key on, crank it with a remote starter where the tractor cranks but does not start so something is causing the fuel solenoid to stay off or the ECU to not fire the injectors).

Anyway, does anybody know if the NX-series lift cylinders have their lift cylinder caps welded on or not?

Service manual diagram

The source where a plastic shield is covering up the cylinder's cap so I cannot see if it is welded or not.

 

[MinnesotaEric]

Since my tractor has not been wanting to start, it has taken me a bit to get around to the lift cylinder.

So things to know:

1) the three-point lift cylinder is mounted RAM up and so with the plastic guard in the way, you will not see crap collecting on top of the dust seal. Thankfully, one bolt holds the guard on each lift cylinder and I suggest popping off the lift cylinder guards once a year with the three-point raised to clean up the dust seals on the lift cylinders.

2) it is pretty easy to get the lift cylinders off, just make sure the three-point is all the way down before cracking open the cylinder's hydraulic line.

3) to remove the lower pin, I did need to grind on the heel of the lower pin's flag a little to get the clearance to remove the pin as not doing so would require dropping the entire drawbar.

 

[5030]

How refreshing to actually see a CLEAN tractor being worked on. Clean speaks volumes about the owner.

Always amazes me when owners post up pictures of filthy tractors for all to see.

 

[dusty3030]

You’re probably the only one on the website who has taken one of those off.
Did you figure out your no start?
I think I’m going to send my NX6010 down the road. I haven’t had a chance to pick it up from the dealer they’ve had it a month or so had to be split at just over 500 hours. Supposedly fixed now. One of the splined couplers on the shaft between the hydro unit and the sub trans let go. No apparent reason why. Its never been rough housed all I ever used it for was mowing and spraying. Most of the time the loader wasnt even on it.

It broke down on me when I needed it most this year so I bought a cab MX5400 to replace it already.

 

[Harry in Ky]

Looking at your diagram I would say item 4, the "steal" ring is the key here. A number of single acting cylinders use that method. The difference here being that the one's I'm familiar with use a straight open port for the oil supply. You can look (and work) through the port to position the rod so you can work the "steal" ring out of its groove. Then the rod slides out and exposes the seals and wiper. With that welded elbow block for the fitting I don't see how you can do that.

 

[MinnesotaEric]

You’re probably the only one on the website who has taken one of those off.
Did you figure out your no start?
I think I’m going to send my NX6010 down the road. I haven’t had a chance to pick it up from the dealer they’ve had it a month or so had to be split at just over 500 hours. Supposedly fixed now. One of the splined couplers on the shaft between the hydro unit and the sub trans let go. No apparent reason why. Its never been rough housed all I ever used it for was mowing and spraying. Most of the time the loader wasnt even on it.

It broke down on me when I needed it most this year so I bought a cab MX5400 to replace it already.

I have not puzzled out the no start. With the key it will not crank. Randomly, with the key on it will crank but not start using a remote starter. Today, since I needed it to start so I could get my Cat2 quick attach off, I ended up putzing through the relays, and while I have an entire box of new relays, my relays are ever-so-slightly bigger so I cannot fit them side by side into the fuse box without "fitting" them like a gunsmith. Anyway, I eventually got the tractor started with the key on and my remote starter, but I do need to get to the bottom of the no-start issue this summer.

Looking at your diagram I would say item 4, the "steal" ring is the key here. A number of single acting cylinders use that method. The difference here being that the one's I'm familiar with use a straight open port for the oil supply. You can look (and work) through the port to position the rod so you can work the "steal" ring out of its groove. Then the rod slides out and exposes the seals and wiper. With that welded elbow block for the fitting I don't see how you can do that.

I'm bringing the cylinder over to Matt at Boyer Mechanical in Bemidji where he can chuck it up in a laith to cut the weld off of the cap and replace the guts and weld up the cylinder again. What I did remember is years ago the bolt holding the flag for the right side lift arm pin fell out and the lift arm pin did a Peter Pan never to be seen again To get back to work, I shoved whatever pin I had and a snap ring in to get back to work.

Now, I cannot find the part number so I'm bringing the left side liftarm pin with me to Bemidji and popping into the Bobcat dealer to see if they can find it since it is metric.

 

[MinnesotaEric]

Matt at Boyer Mechanical in Bemidji was able to cut down the weld, source new seals, and weld up my old cylinder for $135. Call that a win. I was prepared to grind out any leaking weld and reweld it, but Matt got it right the first time. I did provide the service manual diagram of the lift cylinder posted above that shows the internal size (page 11-35 from my service manual), and Matt shared that it helped him confirm the seals needed.

Service-wise, I suggest popping the plastic covers off the top of the lift cylinder and wiping the junk off of the cylinder dust seals once in a while.

 

[Threepoint]

Nicely done, Eric. Thanks for posting this. BTW, I noticed the manual side link on the right-hand lift arm in one of the pics. Didn't you have a top n' tilt setup at some point?

 

[MinnesotaEric]

Nicely done, Eric. Thanks for posting this. BTW, I noticed the manual side link on the right-hand lift arm in one of the pics. Didn't you have a top n' tilt setup at some point?

I still have a top link, but the hydro side link turned into a hassle for what I use my tractor for. Eventually, the bottom broke off of the hydro side link and I ended up welding it back on, better while making a video of how I did it.

I've now moved on to new problems....

 

[JimR]

I had a no start issue with my NX4510HST a few years back. It was the wiring harness where it plugs onto the ignition switch. It had just rattled itself loose a bit. I pushed it back on and it has been fine ever since. Hopefully your problem is just as simple.