Bobcat 610 problems

[Dirtball]

Hi,
I've had some problems with my Bobcat 610. I acquired this unit around Christmas. I figured out the water in the hydraulic oil problem and cured that one. I located this site and learned a few things about my unit that I had no idea it did. The float feature was the first. Secondly, some one was talking about the small lever next to the seat adjusts the belt speed. By golly that works pretty good. Anyhow, my latest problem seems to be the drive chains. My large chains seem to be ok. The chain that drives the big chainwheel seems to be having a problem staying on the chainwheel. I opened the panel up the other day and had to put the chain back on. It ran fine yesterday, but when I pulled it out to do some work this morning it pitched the chain again. I'm thinking that I may have a broken link or something here. I've seen links break on one side and it's hard to find them when they are half submerged. They don't stay on the chainwheels. Since the idler takes the slack out, it's the only way the chain can come off. I think I'll replace my chain and try that. Anyone out there experience this problem?
Also, if anyone has any of those big caps for the clutch shaft ends, and would like to sell them, let me know. Thanks, Dirtball

[Dirtball]

Opened the panel yesterday and found the chain had come apart at the master link. Had a time trying to get the chain under the large chainwheel and I decided to look the chain over. It was worn some. Not terrible. Decided to replace it anyway. Got the new chain in place and drove about 20 feet before the chain let go again. I'm certain that it will be the master link. I found the remnants of 3 others in the sump. I'm thinking about not using a master. That way nothing can unclip it. Anybody had anything like this? I think the chains must be rubbing to unclip the master. Am I missing a spacer somewhere? :O)

[tropicare]

Check your bearings! I met a young guy who was using an m-610 and was trying to figure out why the chain kept comming off, but his bearings on the variable drive pulley were worn and the chain was riding high on the sprocket teeth. The strain wore out other bearings making the whole assembly rock and rub. Definately look at your sprocet teeth for curving

[Dirtball]

EUREKA! Some dummy put the front final drive nuts on and didn't peen the washers over.
The right washer was peened over into the flat on the chainwheel, but wasn't peened over to keep the nut from backing off. The left one had a perfectly flat washer.

[Bobcatter]

While we are on the topic of throwing chains, I threw a chain one time and it was after I had installed a new alternator belt. I had to remove the splice on the split shaft to install the belt, and that shaft is connected to the sprokets under the side panels. Either I had bumped the shaft toward the outside or I did not get the splice tight enough, the result was the sprocked was out of alignment. Soooo. something else to keep in mind? I finally got in there and completely degreased that split shaft/splice and retightened everything. Has worked for..... another 50 hours or so, no problems.

[Dirtball]

Hmm.. I'll keep that in mind when I have to do that. So far I'm staying together. Probably have a few hours on since I tightened the fron shaft nuts.

[Dirtball]

Think I finally have discovered the root problem. After using the 610 for a few more hours, it pitched the left secondaries again. This time I disassembled the whole side, and found that the jack shaft plate had broken the weld. The original weld had actually held and the plate fractured. This allowed the large sprocket to shift back and forth enough to allow the secondary and final drive chains to rub. The secondaries always lost. And, the rear axle nut was loose, allowing slop in the rear sprocket. Tightened and peened.
After pulling the jack shaft assembly apart, and finding out that the bearing is a dual row needle bearing. I re-welded the back plate. Re-assembled the needle bearing, and adjusted everything to specs. Wow! Does that side work smooth now. There is no play anywhere. Now I have to do the right side again. I suspect that the rear nut is loose on it too.
If anyone has any qualms about working on their machine, don't. It is really a simple device. Just don't get in a hurry. Chains can be obtained at TSC, Lowes and lots of other hardware supplies, for less than half of Bobcats' price.

[Frankc]

Just bought a 1980 Bobcat 610. Will try to use it with a home made tree shear. Hope it works.
Just wondering if my John Deere hyd oil will work in the hydraulics. Hate to get different oils.
Was also wondering what is best oil to use in motor. Need to change filter and oil Saturday. I have a bucket and set of forks. All with quick attach. Thanks If emailing me pit skidsteer in subject line. Thanks again. Frankc

[Dirtball]

Hey ! Glad to hear that there are more "antiques" still running. Mine doesn't get much use, but when I need it, I NEED IT!
On your question about oil. I use a light hydraulic oil. I tried the heavy duty hydraulic oil and it seems to like the lighter oil when it's really cold. Just check on what weight oil the John Deere oil is. The light is 10w and I think the heavy duty is 20w. I can't see any reason that it shouldn't work or hurt anything. The innards are pretty stout.
As to engine oil. I assume that you have a Wisconsin V4. 10-40 will probably work just dandy. The multi-vis oil makes it easier to start in cold weather and still provides enough viscosity to withstand the higher temps that the aircooled engine produces. If you are using it enough to justify changing oil with the seasons you can use a 10-30 in the winter. Keeping the filter clean is the key to longevity.
Someday, when I get ambitious, I'll have to cut my bucket loose and make a few more impliments. Evidently, one of the previous owners only used the bucket. It probably rattled and so they welded the bucket in place. I built a hay spike that set in the bucket, but the spike is too far forward to pick up a round bale. I can't keep the rear end on the ground. So, I just scoot them around.

Hey! Send me a pic of your shear. Sounds interesting. Thanks.

[Frankc]

Thanks for the info on oil. That is what I planned on using. I sent off for a set of plans for the tree shear. I had an Idea and it led me to buy some plans. Everything was used with scrap metal I had. Yes, I tore the first on up so I continued to rebuild and support everything. That also tore to pieces good. Then I got hold of some heavy tubing 4 x 4 x 1/2" and some was 4 x 6 c 3/8". The plans gave me a good Idea of what to do to make one work. Had to do more after the heavy one but now works great. It cuts about 6" trees. The Elms gave me a hard time, they would not cut through. I was like elastic. The Oaks just snapped off good. Hope I can post a picture. Here goes. I don't have it on my web site as of now.. So maybe later on.
Both wheels fell off of my 4020 JD. It bit the dust. Got the parts in this evening. Will have it repaired tomorrow, I hope. I was wondering if you know of a site where I can download a manual for this 610?

[GardenPrairie610]

I found a broken bolt on one of my hubs. Any tips on replacing it? It's a 610, and she's my baby.