Greetings again folks, I ended up with the 642 that a friend bought needing a lot of TLC. He was not very mechanically inclined and was looking for a next to new CHEAP machine. I am looking to obtain a copy of the Operators manual and the shop manual for this machine. Until I can locate the books I have two questions. First I am trying to locate and service a lube point that is supposed to be a universal joint of some sort between the engine and main hyd pump. I need to find out how to get to it so I can grease it. Secondly It seems that the left drive may have a drive chain idler out of adjustment. During hard left turns and backing up out of a hole I am getting a very hard CLUNK. If I don't release pressure on the stick the CLUNK is repeated until the load is released or lessoned. Oh, one more thing. I have an old 610 that I am going to sell and I am used to those steering clutches. This 642 is hydrostatic and the steering is very harsh. Is there some way to soften the harshness of the engagement of the steering???I sure am thankful to have access to this site and to be able to pick all the brains out there. Merry Christmas to everyone. Have fun, buckshot
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SkidRoe
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The hydro drive should be smoother than your old clutch machine. Two things come to mind:
1. There is a block that the case drains connect to that also contains sintered bronze filters. These likely need to be cleaned / replaced.
2. If the above does not fix the issue, I would turn my attention to the chain case. Make sure the chains are not too loose and that all of the axle/sprocket nuts are tight.
My $0.02 - SR
1. There is a block that the case drains connect to that also contains sintered bronze filters. These likely need to be cleaned / replaced.
2. If the above does not fix the issue, I would turn my attention to the chain case. Make sure the chains are not too loose and that all of the axle/sprocket nuts are tight.
My $0.02 - SR
thank you Skidroe for your help. I found more Info on the lube question on the U joint. I will have to get a longer hose for my grease gun and get the cab up. I still am looking for info on how to adjust the left side drive chain. I have no manual . A picture of what we are talking about would help. I am a visual kind of person. Thanks Have fun. buckshot
As far as I know, there is no drive chain adjustment. When they are loose, they're shot. I think.some 40 series had wear blocks the chains rode against, but I can't recall. My brain has blocked most of the terrible memories of working on those miserable chaincase.
Bobcatdan, OK, that being said where do I go to see about changing the drive chain? Are there any pics on the process. I still have no manual. I find it hard to understand that if there is a chain drive from front to rear wheel that there would not be some kind of idler sprocket to adjust the chain tension......
walio123
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There are 2 chains for each side. Not adjustablle. Write an email I have those manuals.
There are four chains, one for each wheel. Axle tubes are fixed as well as the motor carrier. To replace a chain, you either pull the axle shaft to let the sprocket come free or just cut the chain. You can get either a complete chain, or one that is not. The non connected chain can be wrapped around the sprockets and then the master link can be pressed in the machine.
Can anyone tell me if the drive chain replacement instruction information and pics are located in the shop repair manual and if so what chapter is it in? I have yet to obtain one of the manuals. If anyone has any pics or might point me in the right direction I sure would appreciate it. What are your overall views of the 642. Thanks Have fun. buckshot
bobbari123
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hi walio123! i tried to email you , but didn¨t work. can you send manual for me? i have bobcat 641. thanks.
OK guys, has anyone been lucky enough to be able to remove one link of drive chain rather than replace the entire chain ? If I am going to have to replace the drive chains where is a good place to obtain chain on the internet ? Also what size chain should I be looking for for the Bobcat 642 ? Is heaver the better choice ? Thanks. Have fun, buckshot
SkidRoe
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If your chains are that loose and your sprockets are still in good shape, replace the chains.
There is nothing special about the chain, I would just avoid any cheap, off-shore brands. Tractor Supply or any bearing/driveline retailer should be able to help you.
HTH - SR
Loose chains indicate they are stretched out. Replacing them (ALL) is the best option. Otherwise, chains can bind up & cause far more damage than just to the chain. I'd replace ALL chain despite the costs. I am just not a big fan of doing a job twice.
OK, I can see that replacing is the way to go. What about the size of the chain?? Is the use of larger / heavier chain an advantage ? I have seen some people talk about size 60 to 80 but cant find any size that is OEM. I would spring for heavier chain if there is longevity or abuse advantage.
SkidRoe
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Pretty sure your machine uses #80 chain, just like the 7XX series machines.
This chain is already pretty heavy duty. Like I said before, it is more important to buy a quality chain. I doubt that there would be much of a gain in going to #80H chain, and there may not be clearance either.
HTH - SR
I am going to plan on changing the chain. If I was to buy bulk chain how long a piece would I have to buy to make sure I obtained enough for the four chain replacement ? I read that Diamond is one chain maker. Are there any more companies that any of you guys have dealt with that are quality chain manufactures ? I would like to stay away from chinese crap. Thank you to all you guys for all of the information. Have fun, buckshot
I went to the local Bobcat dealer to find out more info on changing the chains. They could not tell me what size the chain is or how long each length needs to be. They only said the OEM chain comes in closed length. which means I would have to brake it and re connect unless I wanted to remove the sprockets (I think)... I went to NAPA and found that they sell boxes of #80 chinese chain in 10 foot lengths. Before I take it apart I am interested in finding out how much chain I need per length. I may be able to save some money buying bulk. It would be nice to get two lengths out of a 10 foot box. If any of you guys have ever replaced this chain I would be interested in your experience. Thanks for your help Have fun, buckshot
I thought one box would do two, but don't quote me on that.
Tazza, Do you know of any chain made in the US ? I think Diamond is made here but not positive. I am looking for a few other companies to check out and compare before buying. I don't want to buy any chinese.......... Thanks
Sorry, not a clue. These days, most things are made in China, yet some are made to special standards, so they are actually quality. I'd ask the supplier if it is quality, and not just Chinese crap.
Not sure how true it is, but I heard that NTN or Timkin bearings are made in China now, but they have been given strict guide lines of the materials that must be used to maintain their reputation of being the best. Not the usual mentality of make them as cheap as possible and the quality doesn't matter.
