450c blade lift cylinder

[roadasprin]

Hello this is my first post here ,have read alot of articles and stories here so finally decided to register and join the fun. I have a 450c that the left blade lift cylnder leaks. having worked on diferent equipment for years ,mostly older stuf.I need to know the secret of repacing the seals on the cylinder. I used a spanner wrench and the lock nut just keeps spinning around. from the parts breakdown it shows a snap ring holding the packing assembly in .my question is how do you hold the inner part the lock ring threads onto so the lock ring can be unscewed. If any of you folks everdid this or maybe have a manual to help me along I would appreceate it.

[KenP]

Welcome to the forum. I resealed my first hydraulic cylinder on my crawler a few months back so I'm familiar with what you're trying to do. I've got my service manual in front of me right now, but its not going to be of much help to you. It says:

1. Clean the cylinder with diesel fuel and be sure the disassembly area is clean.
2. Clamp the cylinder in a vise to prevent it from turning. Use a spanner wrench to remove spanner nut from end of cylinder.
3. Push the rod guide into the barrel far enough to remove the snap ring with screw drivers. DO NOT push rod guide too far into the barrel or the rod guide O-ring will enter the oil port and be damaged.
4. Remove piston rod, rod guide, and piston from the barrel.

If I understand your problem correctly, when you try to unscrew the spanner nut, the rod guide is turning with it.
I wondered if that could be a problem when I took mine apart. In my case it wasn't as the area where the rod guide met the snap ring was full of rust. In fact, once I got the spanner nut off and the snap ring removed, I had to use a winch to pull the piston and rod guide out of the end of the barrel.
Seems like they rely on the friction of the rod guide seals against the barrel to keep the guide from turning when you use the spanner. In your case, this isn't working very well and the spanner nut needs more torque than the guide will hold.
Many of the guys here have lots of experience with these, so I'll look forward to their responses.
In the meantime, I'd put plenty of penetrating oil on the spanner nut thread and let it have some time to do its work. Then I'd heat it gently (hey, you're going to replace the seals anyway, right?) until warm. Then, I'd use a hammer and drift rod to tap the spanner nut to see if it will move under impact relative to the rod guide. If you can break it loose, you can use your spanner wrench to undo it.
The good news is that once you have the cylinder apart, its pretty easy to change the seals. Toughest part for me was getting the nut off of the rod piston end.
KenP

[roadasprin]

Thanks or the reply I though maybe the cylinder had to be all the way forward and the end would hold the inner part so the lock nut could be removed . guess Maybe i will try some heat and my air hammer with a blunt drift in it to try and shock it loose. No rust on this one has been seeping oil for 2 yrs just time to fix it ,lol.price of seals is less than the oil nowadays.

[KenP]

Hopefully, that will work for you. The front face of the piston is smooth as is the back face of the rod guide, so no matter where you put the piston in the bore, there's no engagement between the two. Hope that makes sense from my description.
Mine was also rust free on the outside of the cylinder, but once I got the spanner nut off, there was rust all around the snap ring and the front of the rod guide. Took me a while to dig the snap ring out.
Seems obvious, but make sure you've got any pressure out of the cylinder before you go after the snap ring.
Let us know how it goes.
KenP

[roadasprin]

Thanks for all the help I got the cylinder apart with no problem . Used a air chisel with a blunt drift.and the lock ring turned off without and problem ,once it broke loose the first turn the spanner wrench took it off. then the rest was like the book said. John deere wanted 136.for a cylinder kit .I went to a local hydrulic supply shop and got all the parts for28.00. its all back together and works fine . No leaks Thanks again!

[KenP]

Outstanding! Always a good feeling when the plan comes together and everything works.
Saving a bunch of bucks at the same time doesn't hurt...
KenP