642B Creeping and jumpy

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dines78

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Oct 9, 2006
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Hi, I have an 88' 642B I just restored. The problem I have is trying to adjust for neutral. I spent an hour and a half trying to adjust the sticks and got nothing. There is virtually no neutral there. Also, the machine is very jumpy or jerky especially in reverse. Any suggestions would be helpful. Next stop, The dealer!
 

Tazza

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Did you replace the pintle bars and pucks? If there is any wear in either they can be absolute murder to get rite. As for being jerky, are you sure its not because its sensitive? i have a machine that is awfully touchy and its as if it jerks but its just me as i get thrown backwards of forwards moving the levers more. I have tried many times to get it to center, i still can't get the rotten thing rite.
 

pondfishr

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Oct 11, 2005
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Did you replace the pintle bars and pucks? If there is any wear in either they can be absolute murder to get rite. As for being jerky, are you sure its not because its sensitive? i have a machine that is awfully touchy and its as if it jerks but its just me as i get thrown backwards of forwards moving the levers more. I have tried many times to get it to center, i still can't get the rotten thing rite.
When you mention the pucks are you talking about the 4 bushings under the operator cab that connect the hand levers to the hydrostats. I have a 743 that has the same problem "creeping" and I replaced two of them and it helped some. I plan on replacing the other two tomorrow to see if it helps more.
 

Tazza

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When you mention the pucks are you talking about the 4 bushings under the operator cab that connect the hand levers to the hydrostats. I have a 743 that has the same problem "creeping" and I replaced two of them and it helped some. I plan on replacing the other two tomorrow to see if it helps more.
Thats the ones, they rest against the stops to hold the hydrostats center.
The thing is, the stop bars do wear too, they can be flipped over to give you a fresh side if they haven't already been done. To make it easier you really should have them flat for the new round pucks, not essential but it does make the job easier.
They can be a swyne to replace, just take your time and be patient.
 

dines78

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Oct 9, 2006
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Thats the ones, they rest against the stops to hold the hydrostats center.
The thing is, the stop bars do wear too, they can be flipped over to give you a fresh side if they haven't already been done. To make it easier you really should have them flat for the new round pucks, not essential but it does make the job easier.
They can be a swyne to replace, just take your time and be patient.
Thanks for all the help. As of right now I'm in the process of replacing four worn out bushings in the pintle arms. The stop bars have some wear so I'm flipping them and need to do some work on the pucks.They also have flat spots on them.I just might order new ones if not too highly priced. Any way I'll keep you posted on my progress and thanks again.
 

pondfishr

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Oct 11, 2005
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Thanks for all the help. As of right now I'm in the process of replacing four worn out bushings in the pintle arms. The stop bars have some wear so I'm flipping them and need to do some work on the pucks.They also have flat spots on them.I just might order new ones if not too highly priced. Any way I'll keep you posted on my progress and thanks again.
I finally got all 4 of the bushings done tonight it was not good but not too bad. I replaced the bushings on the machine without removing the steering linkage, taking a 3/8's all thread rod with nuts washers and a socket used for the puller. I rigged it together like a wheel puller and then used it as a press to insert the new bushing back in place. The steering levers are considerably tighter but I still have some creeping. I guess my next step is to adjust the steering linkage. In the earlier post when you mentioned stop bars are you talking about the pintle bar that rests against the cams? Do I turn the pintle bar "two separate brackets held on with two bolts each" over or is it something else? That is what my Bobcat manual calls it on page 3-6 in the steering and linkage section. I plan on giving it a shot in the next few days and really would like to get this fixed. It does not creep much but enough where you have to turn it off anytime you would think of leaving the machine.
 

Tazza

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I finally got all 4 of the bushings done tonight it was not good but not too bad. I replaced the bushings on the machine without removing the steering linkage, taking a 3/8's all thread rod with nuts washers and a socket used for the puller. I rigged it together like a wheel puller and then used it as a press to insert the new bushing back in place. The steering levers are considerably tighter but I still have some creeping. I guess my next step is to adjust the steering linkage. In the earlier post when you mentioned stop bars are you talking about the pintle bar that rests against the cams? Do I turn the pintle bar "two separate brackets held on with two bolts each" over or is it something else? That is what my Bobcat manual calls it on page 3-6 in the steering and linkage section. I plan on giving it a shot in the next few days and really would like to get this fixed. It does not creep much but enough where you have to turn it off anytime you would think of leaving the machine.
Thats how i pulled my old bushings out and re-installed them too, but i did cheat and use an air ratchet :)
The stops are the pintle bars yes, remove the pintle bars and flip then 180 degrees (if the other side hasn't been used) to get a nice smooth edge. Its best if you replace the 4 cams or pucks, whatever your manual calls them too.
As for creeping, can't you adjust the brake to stop it moving? It should be set so the machine will not move with it engaged, even if you push the levers forward on purpose.
On the one i have thats not rite, if i put the revs up a notch and lock the park brake in it will not move. If i don't give it a few revs it stalls the engine.
 

dines78

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Oct 9, 2006
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Thats how i pulled my old bushings out and re-installed them too, but i did cheat and use an air ratchet :)
The stops are the pintle bars yes, remove the pintle bars and flip then 180 degrees (if the other side hasn't been used) to get a nice smooth edge. Its best if you replace the 4 cams or pucks, whatever your manual calls them too.
As for creeping, can't you adjust the brake to stop it moving? It should be set so the machine will not move with it engaged, even if you push the levers forward on purpose.
On the one i have thats not rite, if i put the revs up a notch and lock the park brake in it will not move. If i don't give it a few revs it stalls the engine.
Thats good advice for anyone needing to change their bushings. I used a nut and bolt with two sockets to remove and replace my bushings. It was the only way to get to the back bushing along the the help of an air ratchet.
 
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