Roto Swivel on 610 Bobcat

[bobcatman88]

I am trying to remove the roto swivel on a 610 bobcat. I currently have the variable sheave off and I have the little snap ring off that removes the swivel where the hydraulic hose connects to and there are two little bearings on there that is removed. Now what is the next step in getting to the bolt that I am supposed to take off so I can take the stationary sheave off the drive shaft? the piston pulls out but does not come out and I still have not found the bolt I need to see to take the sheave off. right now I see a couple of roll pins that look like they are for alignment of something. I also took off a really big snap ring that looks like it has a big brass bushing and a oil seal on the inside of it.

 

[6brnorma]

You've taken apart more then you should have which limits your options to remove the assembly……you can still make it work though. Put the "end cap" back on (which fits over the stainless steel piston), then put the snap ring back on (that fits over the stainless steel piston & and inside of the "end cap". Then use two pry bars behind the "end cap" using the side of the bobcat for leverage to pull the entire assembly out of the sheave itself and that will expose the retaining bolt that goes into the crank shaft.

 

[6brnorma]

You've taken apart more then you should have which limits your options to remove the assembly……you can still make it work though. Put the "end cap" back on (which fits over the stainless steel piston), then put the snap ring back on (that fits over the stainless steel piston & and inside of the "end cap". Then use two pry bars behind the "end cap" using the side of the bobcat for leverage to pull the entire assembly out of the sheave itself and that will expose the retaining bolt that goes into the crank shaft.

Also….there were four very small and vital parts that were behind those bearings you are seeing. I hope you didn't lose or damage those parts……..each is critical.

 

[bobcatman88]

Also….there were four very small and vital parts that were behind those bearings you are seeing. I hope you didn't lose or damage those parts……..each is critical.

Thanks for the help. The service manual was not really clear on what to exactly take out. And yes I do have all of those little parts and I put them back in there very carefully. When you put that "end cap" back on to pull the piston out its going to come pretty hard right? Feels like it has some suction on it when you are pulling on it. Also do you know if there are any updated service manuals for the 610 with more accurate information or is it only the originals that are still being used. Also if you have any useful pointers on removing the engine that are not mentioned in the manual that would be helpful to. I am doing this to remove the engine to have it overhauled.

 

[Tigerhaze]

Thanks for the help. The service manual was not really clear on what to exactly take out. And yes I do have all of those little parts and I put them back in there very carefully. When you put that "end cap" back on to pull the piston out its going to come pretty hard right? Feels like it has some suction on it when you are pulling on it. Also do you know if there are any updated service manuals for the 610 with more accurate information or is it only the originals that are still being used. Also if you have any useful pointers on removing the engine that are not mentioned in the manual that would be helpful to. I am doing this to remove the engine to have it overhauled.

You have to be a little careful about service manuals for the 610- I know that there was a serial number split for "early" and "late" Model 610s because my Model 500 manual also covered the early 610s. There were apparently also running updates (replacement pages) for some of the manual sections so I would be careful with that as well if using an original manual.

 

[6brnorma]

You have to be a little careful about service manuals for the 610- I know that there was a serial number split for "early" and "late" Model 610s because my Model 500 manual also covered the early 610s. There were apparently also running updates (replacement pages) for some of the manual sections so I would be careful with that as well if using an original manual.

There's not really much suction……what you are feeling are two large o-rings that must make it past the lock ring groove inside the sheave. Sometimes it is best to push the piston into the sheave slightly, exposing the groove and use some emery cloth on any burrs that may have formed. The removal method I described to you is the one suggested by Bobcat…..that said, I think it is the worst and almost never use it. I have a snap-on 'pitman arm' puller (part #CJ119B) that I removed the screw and place on my slide hammer…..works like a charm behind the "end cap". I work on 610s all the time so I have it but I don't recommend buying one for one machine/time use.

 

[bobcatman88]

There's not really much suction……what you are feeling are two large o-rings that must make it past the lock ring groove inside the sheave. Sometimes it is best to push the piston into the sheave slightly, exposing the groove and use some emery cloth on any burrs that may have formed. The removal method I described to you is the one suggested by Bobcat…..that said, I think it is the worst and almost never use it. I have a snap-on 'pitman arm' puller (part #CJ119B) that I removed the screw and place on my slide hammer…..works like a charm behind the "end cap". I work on 610s all the time so I have it but I don't recommend buying one for one machine/time use.

I ended up getting it out by using their method. It didn't come out to bad. Next question the swivel rotor I took off the wrong snap ring and pulled out the swivel. Then a little washer spring and plastic or carbide looking seal fell out. The seal or plastic piece was broken. Anyone have any idea where I could get another swivel and pieces inside? Also is it best to use the recommended bearing puller to get the stationary sheave off the crankshaft or is there another better way?

 

[6brnorma]

I ended up getting it out by using their method. It didn't come out to bad. Next question the swivel rotor I took off the wrong snap ring and pulled out the swivel. Then a little washer spring and plastic or carbide looking seal fell out. The seal or plastic piece was broken. Anyone have any idea where I could get another swivel and pieces inside? Also is it best to use the recommended bearing puller to get the stationary sheave off the crankshaft or is there another better way?

Those parts are all available through Bobcat. I would recommend a couple of each in case of foul up when reassembling. The 'carbide' seal (Part #6516301) is about $20.00 and is the easiest to break when reassembling so be careful with it……also O-ring (#25k-20005), spring (#6516302), and guide [steel washer] (#888670) are all a couple of bucks each. If you need the swivel it too is available through Bobcat but is nearly $100.00……if you're going to do all that, I'd replace the snap rings and bearings also. Now for the stationary sheave……there are two small bolt holes at the base of the sheave…..put short bolts in the holes (snug), use a bearing splitter and a puller to pull the sheave. Under no circumstances pry behind that sheave…..it is EASY to break and over $600.00 to replace.

 

[bobcatman88]

Those parts are all available through Bobcat. I would recommend a couple of each in case of foul up when reassembling. The 'carbide' seal (Part #6516301) is about $20.00 and is the easiest to break when reassembling so be careful with it……also O-ring (#25k-20005), spring (#6516302), and guide [steel washer] (#888670) are all a couple of bucks each. If you need the swivel it too is available through Bobcat but is nearly $100.00……if you're going to do all that, I'd replace the snap rings and bearings also. Now for the stationary sheave……there are two small bolt holes at the base of the sheave…..put short bolts in the holes (snug), use a bearing splitter and a puller to pull the sheave. Under no circumstances pry behind that sheave…..it is EASY to break and over $600.00 to replace.

ok good to know...It was the carbide seal that was broke inside. There was a little washer another little black o-ring or flat faced black rubber piece that looks to be the size of the washer. and a spring that came out of there. The swivel itself is ok but like you said I will put new bearings in and do it right. Thanks for the helpful information I have the bolts in place on the base of the sheave now I just need to go find myself a bearing splitter and puller to get it off.

 

[6brnorma]

ok good to know...It was the carbide seal that was broke inside. There was a little washer another little black o-ring or flat faced black rubber piece that looks to be the size of the washer. and a spring that came out of there. The swivel itself is ok but like you said I will put new bearings in and do it right. Thanks for the helpful information I have the bolts in place on the base of the sheave now I just need to go find myself a bearing splitter and puller to get it off.

Heat is your friend when pulling the sheave and don't try to 'punch' the swivel out of the bearings. It will deform the end and not function properly……(ask me how I know) ;-)

 

[bobcatman88]

Heat is your friend when pulling the sheave and don't try to 'punch' the swivel out of the bearings. It will deform the end and not function properly……(ask me how I know) ;-)

Heating won't hurt the crankshaft??? Guess while I am on here do you know if the variable speed valve has a detent in it to keep it in high speed when you engage the high speed lever you have to.hold it to keep going fast as soon as you let off the Bobcat slows down.

 

[jerry]

Heat is your friend when pulling the sheave and don't try to 'punch' the swivel out of the bearings. It will deform the end and not function properly……(ask me how I know) ;-)

A;; I can add to this is be sure to put the gland back in the right way. The one I had it had been installed backwards and was ruined from the pressure. At that time bobcat wanted $50 for it but I made it on the lathe from brass and it worked fine.

 

[6brnorma]

A;; I can add to this is be sure to put the gland back in the right way. The one I had it had been installed backwards and was ruined from the pressure. At that time bobcat wanted $50 for it but I made it on the lathe from brass and it worked fine.

Only apply heat to the sheave…..it won't be enough to affect the crank. I believe when you get the assembly rebuilt the problem will be solved with the high speed. That broken (carbide) piece will allow oil to pass and the sheave to return to the lower speed. Pay attention to Jerry's advice…..I use black pvc to drive the piston and gland back into the sheave (1 1/2 inch if memory serves correctly) and be sure the "balance marks" are aligned when you replace the outer sheave.

 

[oldbobcatter]

Only apply heat to the sheave…..it won't be enough to affect the crank. I believe when you get the assembly rebuilt the problem will be solved with the high speed. That broken (carbide) piece will allow oil to pass and the sheave to return to the lower speed. Pay attention to Jerry's advice…..I use black pvc to drive the piston and gland back into the sheave (1 1/2 inch if memory serves correctly) and be sure the "balance marks" are aligned when you replace the outer sheave.

About those "balance marks". Are you referring to the "drilled out" indents? If not, what DO they look like? On a related note; I am in need of the dimensions of the woodruff key that keeps the sheaves aligned. I got a key from Bobcat only to find it is too thick. It appears 1/4" thick and the slot appears 9mm. Any help?

 

[6brnorma]

About those "balance marks". Are you referring to the "drilled out" indents? If not, what DO they look like? On a related note; I am in need of the dimensions of the woodruff key that keeps the sheaves aligned. I got a key from Bobcat only to find it is too thick. It appears 1/4" thick and the slot appears 9mm. Any help?

Oldcatter…….I don't think there is a metric anything on a M-610. Balance marks are not the 'drilled out' indents. Look on the outer sheave, there will be (should be) an arrow pointing towards the rim of the sheave……in line with that arrow and on the very rim of the sheave will be a balance mark. There were two types….one is a straight line (small) cut/scored across the rim….the other was a "v" shaped score on the outer edge of the rim. Identify that and then look for the corresponding mark on the inner sheave. Should you have two different styles of marks…..that in itself is an issue as they will not be a balanced pair.