Bobcat 610 Variable Speed

[Szil66]

Hello! New to the forum and looking for some help! I recently acquired a Bobcat 610, not sure on year and I don't know much about it. I got it for free so I can complain, however I know very little about Bobcats, especially older ones Now, on to my issue. The Bobcat starts and runs fine, however, there is a chattering noise while running that's gets considerably louder and faster when it's changed into high speed. I think the clutches could use some adjustment but I don't think that that is where the chattering is coming from. The hydraulic line on the drive sheave is leaking and slinging fluid everywhere but I can't pin point an exact spot as to where it's leaking from, is there a way to rebuild that whole unit? I appreciate any help! I did buy a manual for it but a lot of it is like a different language to me. I am mechanically inclined but understanding diagrams and literature isn't my strong suit. Thanks!

 

[alchemysa]

The variable sheave is a regular problem with this model. There's a few different versions. It seems that many people ditch the hydraulics altogether and just bolt or weld the sheave to a fixed position. Heres my solution...
http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=95991
But if yours is worth fixing you should be able to get the parts through a Bobcat dealer. Hopefully you'll just need seals.
This link will take you to a 610 parts thread. It also has details of where to go for free manuals and parts diagrams for the 610. I often find parts diagrams are more useful than workshop manuals.
http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=99315
(You'll need to copy and paste any links).
6brnorma is the 610 expert. Hopefully he'll chime in.

 

[Szil66]

The variable sheave is a regular problem with this model. There's a few different versions. It seems that many people ditch the hydraulics altogether and just bolt or weld the sheave to a fixed position. Heres my solution...
http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=95991
But if yours is worth fixing you should be able to get the parts through a Bobcat dealer. Hopefully you'll just need seals.
This link will take you to a 610 parts thread. It also has details of where to go for free manuals and parts diagrams for the 610. I often find parts diagrams are more useful than workshop manuals.
http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=99315
(You'll need to copy and paste any links).
6brnorma is the 610 expert. Hopefully he'll chime in.

Thanks for the reply! And thank you for posting the link with the manuals. The variable speed works fine so I don't necessarily want to mess with the hydraulics it just makes a loud chattering noise in high speed. Not sure if the jackshaft bearings might be bad or of the clutches being worn out causes the noise or what exactly the problem could be. When I take ahold of the jackshaft and try to move it I can't feel any movement but not sure where else the noise would come from. Don'tly want to put a ton of money into it, just enough to make it reliable for simple uses around the farm. When I can get to it, I will pull the drive sheave out and pull it apart and see if I can find my leak but I don't think that's the chattering noise. Sounds like it's in the jackshaft area. Also I was told the blocks have been replaced before but all the bolts are facing the same way and I've read that's incorrect. Any info on how the bolts are actually supposed to be arranged?

 

[6brnorma]

Thanks for the reply! And thank you for posting the link with the manuals. The variable speed works fine so I don't necessarily want to mess with the hydraulics it just makes a loud chattering noise in high speed. Not sure if the jackshaft bearings might be bad or of the clutches being worn out causes the noise or what exactly the problem could be. When I take ahold of the jackshaft and try to move it I can't feel any movement but not sure where else the noise would come from. Don'tly want to put a ton of money into it, just enough to make it reliable for simple uses around the farm. When I can get to it, I will pull the drive sheave out and pull it apart and see if I can find my leak but I don't think that's the chattering noise. Sounds like it's in the jackshaft area. Also I was told the blocks have been replaced before but all the bolts are facing the same way and I've read that's incorrect. Any info on how the bolts are actually supposed to be arranged?

Let's address one issue at a time…..if you put the variable speed sheave in high and it bleeds down, your leak is in the roto-swivel assembly (this is the most common source)….if it does not bleed down it is likely in the variable speed valve (especially the pressure relief rod….second most common leak) it is at the front of the variable speed valve and drips down onto the belt and throws oil everywhere. Can also be coming from the line itself. Pinpoint the leak and we can help you with that.
The "chatter" can be a lot of things but look at your 'driven sheave' (spring loaded sheave) note whether or not the bushings around the three pins have 'ovaled' out or not. Grease the sheave as needed.
The block should have the four center bolts in one direction and the four outer bolts going in the opposing direction. There is a stamp on each half of the block….make sure they are pointed in the same direction.

 

[Szil66]

Let's address one issue at a time…..if you put the variable speed sheave in high and it bleeds down, your leak is in the roto-swivel assembly (this is the most common source)….if it does not bleed down it is likely in the variable speed valve (especially the pressure relief rod….second most common leak) it is at the front of the variable speed valve and drips down onto the belt and throws oil everywhere. Can also be coming from the line itself. Pinpoint the leak and we can help you with that.
The "chatter" can be a lot of things but look at your 'driven sheave' (spring loaded sheave) note whether or not the bushings around the three pins have 'ovaled' out or not. Grease the sheave as needed.
The block should have the four center bolts in one direction and the four outer bolts going in the opposing direction. There is a stamp on each half of the block….make sure they are pointed in the same direction.

I am fairly certain it is leaking from the roto-swivel as is looks like that is where the oil is coming from, the valve doesn't appear to be leaking oil. However, the oil doesn't look like its coming from the line it looks like its from within the roto-swivel and leaks to the sheave and slings the oil from there and covers the belt. I am not entirely sure if it bleeds down or not, it was parked a couple years ago because of the chatter and I only just recently got it running so that I could hear it and try to identify it. Didn't really use it just ran it long enough to address the problems I need to fix. Is there a complete kit for rebuilding the roto-swivel or do I just need to order all the parts individually from Bobcat? The chatter is most noticeable around the driven sheave but was looking for a pin point of where to start looking so thank you for that answer. There are so many bushings and bearings in that small area it's hard to know where to start. The Bobcat is at my place an hour away and can only get up there certain weekends so I am trying to find as much info as I can and get as many parts as I can so I can tackle any repairs at the same time. May just buy the bushings and replace them if it isn't too big of a job.

 

[Szil66]

I am fairly certain it is leaking from the roto-swivel as is looks like that is where the oil is coming from, the valve doesn't appear to be leaking oil. However, the oil doesn't look like its coming from the line it looks like its from within the roto-swivel and leaks to the sheave and slings the oil from there and covers the belt. I am not entirely sure if it bleeds down or not, it was parked a couple years ago because of the chatter and I only just recently got it running so that I could hear it and try to identify it. Didn't really use it just ran it long enough to address the problems I need to fix. Is there a complete kit for rebuilding the roto-swivel or do I just need to order all the parts individually from Bobcat? The chatter is most noticeable around the driven sheave but was looking for a pin point of where to start looking so thank you for that answer. There are so many bushings and bearings in that small area it's hard to know where to start. The Bobcat is at my place an hour away and can only get up there certain weekends so I am trying to find as much info as I can and get as many parts as I can so I can tackle any repairs at the same time. May just buy the bushings and replace them if it isn't too big of a job.

Had some time to tear into some things this weekend and found a few major issues. Pulled the roto-swivel apart didn't look too bad but was sludgy behind the Piston. Going to get new seals for that and hopefully that fixed the leak. I pulled the blocks apart and the block is completely destroyed, the key slot has been wore pretty bad on the one side. It's on the side that runs the alternator and that shaft has a lot of play in it and wear. Guessing those jackshaft bearings need replaced. Should those bearings have any play as far as up and down or should they be tight? I will try to include pictures, hopefully they work. Can I still get the parts or is it something I'm better off finding used?

I took pictures of the bushings and they don't look too bad so I don't think that is where the vibration is from. After looking at the block and feeling the way the shafts turn I'm fairly certain it was caused by the blocks and the jackshaft bearings

 

[Szil66]

Had some time to tear into some things this weekend and found a few major issues. Pulled the roto-swivel apart didn't look too bad but was sludgy behind the Piston. Going to get new seals for that and hopefully that fixed the leak. I pulled the blocks apart and the block is completely destroyed, the key slot has been wore pretty bad on the one side. It's on the side that runs the alternator and that shaft has a lot of play in it and wear. Guessing those jackshaft bearings need replaced. Should those bearings have any play as far as up and down or should they be tight? I will try to include pictures, hopefully they work. Can I still get the parts or is it something I'm better off finding used? I took pictures of the bushings and they don't look too bad so I don't think that is where the vibration is from. After looking at the block and feeling the way the shafts turn I'm fairly certain it was caused by the blocks and the jackshaft bearings

I am not sure how to get the pictures to post or why none of my posts have spaces in between paragraphs. When I go to my profile and click the Use HTML Editor button I try to reply and it won't let me type anything at all. Might have to just copy and paste the urls to see the pictures. Sorry about that.

 

[alchemysa]

I am not sure how to get the pictures to post or why none of my posts have spaces in between paragraphs. When I go to my profile and click the Use HTML Editor button I try to reply and it won't let me type anything at all. Might have to just copy and paste the urls to see the pictures. Sorry about that.

To post pictures copy and paste the the tinypic link for websites, not the link for forums.
To create paragraphs insert this code...
without the asterisks.

 

[alchemysa]

To post pictures copy and paste the the tinypic link for websites, not the link for forums.
To create paragraphs insert this code...
without the asterisks.

The bearings swivel slightly but you should have no up and down movement. If you have up and down movement its possible the shaft has been spinning in a seized bearing, and has worn. Normally the inner race of the bearing should be locked onto the shaft. The bearings are still available but there are a few different sorts. The best ones have a locking collar. 6brnorma will probably comment on this.
The ones in the pics here are not correct but its what I have in mine. Originally they were locked on with Alan screws, but those things are useless so I used some thread (7/16 I think) with a spring washer and locking nut. The threads key slight indents I drilled into the shafts.

 

[Szil66]

Had some time to tear into some things this weekend and found a few major issues. Pulled the roto-swivel apart didn't look too bad but was sludgy behind the Piston. Going to get new seals for that and hopefully that fixed the leak. I pulled the blocks apart and the block is completely destroyed, the key slot has been wore pretty bad on the one side. It's on the side that runs the alternator and that shaft has a lot of play in it and wear. Guessing those jackshaft bearings need replaced. Should those bearings have any play as far as up and down or should they be tight? I will try to include pictures, hopefully they work. Can I still get the parts or is it something I'm better off finding used? I took pictures of the bushings and they don't look too bad so I don't think that is where the vibration is from. After looking at the block and feeling the way the shafts turn I'm fairly certain it was caused by the blocks and the jackshaft bearings

Sorry for the duplicate, just trying this again
Had some time to tear into some things this weekend and found a few major issues. Pulled the roto-swivel apart didn't look too bad but was sludgy behind the Piston. Going to get new seals for that and hopefully that fixed the leak.
I pulled the blocks apart and the block is completely destroyed, the key slot has been wore pretty bad on the one side. It's on the side that runs the alternator and that shaft has a lot of play in it and wear. Guessing those jackshaft bearings need replaced? Should those bearings have any play as far as up and down or should they be tight? I will try to include pictures, hopefully they work. Can I still get the parts or is it something I'm better off finding used?




I took pictures of the bushings and they don't look too bad so I don't think that is where the vibration is from. After looking at the block and feeling the way the shafts turn I'm fairly certain it was caused by the blocks and the jackshaft bearings

 

[alchemysa]

Sorry for the duplicate, just trying this again
Had some time to tear into some things this weekend and found a few major issues. Pulled the roto-swivel apart didn't look too bad but was sludgy behind the Piston. Going to get new seals for that and hopefully that fixed the leak.
I pulled the blocks apart and the block is completely destroyed, the key slot has been wore pretty bad on the one side. It's on the side that runs the alternator and that shaft has a lot of play in it and wear. Guessing those jackshaft bearings need replaced? Should those bearings have any play as far as up and down or should they be tight? I will try to include pictures, hopefully they work. Can I still get the parts or is it something I'm better off finding used?




I took pictures of the bushings and they don't look too bad so I don't think that is where the vibration is from. After looking at the block and feeling the way the shafts turn I'm fairly certain it was caused by the blocks and the jackshaft bearings

Oh my.. that block is a mess isn't it. And it looks like the shafts were further apart than ideal. Does the shaft (generator side) slide in and out of the bearing?

 

[Szil66]

Oh my.. that block is a mess isn't it. And it looks like the shafts were further apart than ideal. Does the shaft (generator side) slide in and out of the bearing?

Yes the block has pretty much had it. Not having much luck finding it online, so probably going to have to talk to Bobcat or find used. I didn't notice that it slid in and out but it has a ton of wobble to it and when you turn it by hand you can just feel the bearing catching and grinding. I have a video but can't get it to upload on tinypic.. File size is probably too big...

 

[alchemysa]

Yes the block has pretty much had it. Not having much luck finding it online, so probably going to have to talk to Bobcat or find used. I didn't notice that it slid in and out but it has a ton of wobble to it and when you turn it by hand you can just feel the bearing catching and grinding. I have a video but can't get it to upload on tinypic.. File size is probably too big...

If you can't get a replacement maybe you could put a groove through the other half of the block.
The worst part of checking the bearings is removing the side cover. Then release the tensioner, remove the chain (it has a removeable link), unbolt the sprocket, loosen whatever (if anything) is locking the bearing to the shaft then pull the shaft 'inwards'. Finally, remove the 4 bolts and the swivel bearing housing.

 

[alchemysa]

If you can't get a replacement maybe you could put a groove through the other half of the block.
The worst part of checking the bearings is removing the side cover. Then release the tensioner, remove the chain (it has a removeable link), unbolt the sprocket, loosen whatever (if anything) is locking the bearing to the shaft then pull the shaft 'inwards'. Finally, remove the 4 bolts and the swivel bearing housing.

I forgot. Theres a small key on the bearing sprocket and some thin washers. Be careful you don't drop them into the oil. Same goes for the chain link.

 

[Szil66]

I forgot. Theres a small key on the bearing sprocket and some thin washers. Be careful you don't drop them into the oil. Same goes for the chain link.

Thanks for the help, doesn't sound too difficult just time consuming.
Will I need to replace the gasket on the backside of the housing or is it usually not an issue?

 

[alchemysa]

Thanks for the help, doesn't sound too difficult just time consuming.
Will I need to replace the gasket on the backside of the housing or is it usually not an issue?

I can't remember what state my gaskets were in. Perhaps I could have removed them in one piece but I wasn't trying to. I made new gaskets for the bearings and the axles out of gasket paper.

 

[6brnorma]

I can't remember what state my gaskets were in. Perhaps I could have removed them in one piece but I wasn't trying to. I made new gaskets for the bearings and the axles out of gasket paper.

Wow….where to start…. personally, I would replace the jackshaft, block/splicer and both of the jackshaft bearings
The jackshaft is still available…Bobcat pt# 6551114….I don't know the price and rarely see them on E-bay. The block is available … Bobcat pt# 6502810….don't know the price but they are available on E-bay quite often….I have some if you need. They are pair/balanced with a mark on each half that needs to be matched up when installed. Bearings are Bobcat pt# 6518862 at $94.00 but you can get them on E-bay any day for $25.00 - $40.00….keywords (RA104RRB) I like the Fafnir the best but Timken work just fine. I hope you can reuse the pulley but if not it is still available….Bobcat pt# 6551201…about $30.00. The bushings in your 'driven' sheave look fine.
Roto-swivel assembly….there are too many parts to list so go to the Bobcat web site (bobcat.com) …. parts and work your way to the exploded view of the assembly. At a minimum I would replace parts #2, 4, 5, 7, 8, 25, 23, 22, 20, 19 and 18. That looks bad but only 20 and 23 are expensive….the rest are only a couple of bucks each. Find a manual and follow it closely for both of these jobs.
Hope this helps.

 

[6brnorma]

Wow….where to start…. personally, I would replace the jackshaft, block/splicer and both of the jackshaft bearings
The jackshaft is still available…Bobcat pt# 6551114….I don't know the price and rarely see them on E-bay. The block is available … Bobcat pt# 6502810….don't know the price but they are available on E-bay quite often….I have some if you need. They are pair/balanced with a mark on each half that needs to be matched up when installed. Bearings are Bobcat pt# 6518862 at $94.00 but you can get them on E-bay any day for $25.00 - $40.00….keywords (RA104RRB) I like the Fafnir the best but Timken work just fine. I hope you can reuse the pulley but if not it is still available….Bobcat pt# 6551201…about $30.00. The bushings in your 'driven' sheave look fine.
Roto-swivel assembly….there are too many parts to list so go to the Bobcat web site (bobcat.com) …. parts and work your way to the exploded view of the assembly. At a minimum I would replace parts #2, 4, 5, 7, 8, 25, 23, 22, 20, 19 and 18. That looks bad but only 20 and 23 are expensive….the rest are only a couple of bucks each. Find a manual and follow it closely for both of these jobs.
Hope this helps.

Just a note…use caution when re-assembling the roto-swivel assembly…..pt# 20 is very easy to break. At $25.00 a copy it can drive your costs up in a hurry if you break a couple of them.
Alchemysa tells everyone how easy this stuff is….keep in mind he is one super mechanically minded Aussie

 

[alchemysa]

Just a note…use caution when re-assembling the roto-swivel assembly…..pt# 20 is very easy to break. At $25.00 a copy it can drive your costs up in a hurry if you break a couple of them.
Alchemysa tells everyone how easy this stuff is….keep in mind he is one super mechanically minded Aussie

"Alchemysa tells everyone how easy this stuff is….keep in mind he is one super mechanically minded Aussie"
He gives me much too much credit. If I had more sense (and money) I'd just replace the parts I spend ages trying to fix. Parts for these things are either non-existent or crazy expensive over here.
Anyway, you can't beat real experience, so fortunately 6brnorma is here.