s300 freewheels when controls neutralized

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Mikej

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I have an 07 s300 that started out giving some grinding and jamming up on the left side drive, now when machine is parked on a slope it will role forwards or backwards on its own. This happens with the park brake on or off. sometimes machine will drive smooth but then lock up. I will feel resistance in the controls and the motor will labor at this point.My question is can a drive motor cause all these symptoms
 

OldMachinist

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Sounds more like a problem in the chaincase than a motor. I'd pop the front cover off and have a look inside. You may have to suck the oil level down to see if something is wrong.
 

frogfarmer

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When the motors get very worn they will creep down a hill without the brake. If the brake is defective it may be the brake mechanism that is causing the problem. A chain case inspection should reveal the problem. Sounds like it could be a few different things causing the issue. High hours and considerable wear cause many components to act up.
 
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Mikej

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was told that motor packed it in and contaminants plugged filter causing back pressure thus releasing brakes. Does this sound reasonable.
 

OldMachinist

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was told that motor packed it in and contaminants plugged filter causing back pressure thus releasing brakes. Does this sound reasonable.
I guess that could happen if you have a 2 speed machine since the brakes are part of the motor.
 

frogfarmer

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was told that motor packed it in and contaminants plugged filter causing back pressure thus releasing brakes. Does this sound reasonable.
Strange things can happen when trash is in the system but I would expect the amount of back pressure required to release the brakes would cause all sorts of other problems. I have not personally seen this happen and would question it being "reasonable" but not out of the realm for possible.
 
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Mikej

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so had new drive motor installed on left side. machine drives fine now but hydraulic oil was low in glass. topped off, ran for a bit then low again. did this several times thinking I needed to purge system. lifted cab to see if there was a leak inside but all dry. finally oil started dripping from belly pan. could the oil be filling the chain case somehow? any ideas?
 

Tazza

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so had new drive motor installed on left side. machine drives fine now but hydraulic oil was low in glass. topped off, ran for a bit then low again. did this several times thinking I needed to purge system. lifted cab to see if there was a leak inside but all dry. finally oil started dripping from belly pan. could the oil be filling the chain case somehow? any ideas?
There are seals on the drive motor carriers. If you had extra back pressure on a motor from a plugged filter, it can damage the seal and push oil past it and into the chain case. Check your case drain filters are nie and clean, if they are, you will need to look at the seals.
If you remove the plug at the front while on flat ground, the oil elvel should be at the bottom of the threads.
 
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Mikej

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There are seals on the drive motor carriers. If you had extra back pressure on a motor from a plugged filter, it can damage the seal and push oil past it and into the chain case. Check your case drain filters are nie and clean, if they are, you will need to look at the seals.
If you remove the plug at the front while on flat ground, the oil elvel should be at the bottom of the threads.
Thanks Tazza, I lifted the cab again today and seen that the chaincase is overflowing with oil so must be those seals. Didn't see on the invoice from the shop that they replaced the case drain filter so I should look at that but have no idea where it is.
 

Tazza

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Thanks Tazza, I lifted the cab again today and seen that the chaincase is overflowing with oil so must be those seals. Didn't see on the invoice from the shop that they replaced the case drain filter so I should look at that but have no idea where it is.
Trace the small hose from the drive motors back to the oil tank/pump. There will be aluminium cans about 1.5" diameter and about 3" long, these are the filters.
 
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Mikej

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Trace the small hose from the drive motors back to the oil tank/pump. There will be aluminium cans about 1.5" diameter and about 3" long, these are the filters.
Talked to the shop today and they said it must be the seal between the drive motor and the chaincase. Told me that chaincase oil was normal when it came to the shop so they must have nicked it when installing new pump. They will go good for the repair (12 hrs labour??) but kind of sucks anyhow as the shop is a 3 hr drive away. Is it not normal practice to change all hydraulic filters after a failure like this or is it sufficient to do just the case drain one? Thanks again Tazza for reading. Machine has 2400 hrs is this about right for a pump?
 

Tazza

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Talked to the shop today and they said it must be the seal between the drive motor and the chaincase. Told me that chaincase oil was normal when it came to the shop so they must have nicked it when installing new pump. They will go good for the repair (12 hrs labour??) but kind of sucks anyhow as the shop is a 3 hr drive away. Is it not normal practice to change all hydraulic filters after a failure like this or is it sufficient to do just the case drain one? Thanks again Tazza for reading. Machine has 2400 hrs is this about right for a pump?
12 hours? HA it's not that big of a job, especially for someone knows what they are doing. Remove drive motors, remove seal, re-install seal, re-install motor. That's it, nice and simple. Yet the drive motors are quite heavy.
2400 hours for a pump is quite low, they should easily do 10,000 some have done a lot more. They should do at least what the engine generally does, 6,000 hours. It only takes a small meat fragment getting past a filter and gets between the rotating group and wear plate to cause serious damage. Even excessive heat from a blocked oil cooler can do it by thinning the oil out too much.
 
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Mikej

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12 hours? HA it's not that big of a job, especially for someone knows what they are doing. Remove drive motors, remove seal, re-install seal, re-install motor. That's it, nice and simple. Yet the drive motors are quite heavy.
2400 hours for a pump is quite low, they should easily do 10,000 some have done a lot more. They should do at least what the engine generally does, 6,000 hours. It only takes a small meat fragment getting past a filter and gets between the rotating group and wear plate to cause serious damage. Even excessive heat from a blocked oil cooler can do it by thinning the oil out too much.
was told they have to remove everything above chaincase and such so sounded like it had to be done from inside chaincase. I don't have a clue and cant find any pictures online of the procedure. maybe getting bamboozald?
 
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Mikej

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was told they have to remove everything above chaincase and such so sounded like it had to be done from inside chaincase. I don't have a clue and cant find any pictures online of the procedure. maybe getting bamboozald?
kind of thought that the drive motor was a sealed unit on its own
 

antfarmer2

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kind of thought that the drive motor was a sealed unit on its own
The seal that is leaking if the oil from the hydro is getting to the chain case is a easy Fix on my 743 seals were 16 bucks get to the drive motor take off and cap off lines and nips to keep crap out take off motor there is the seal on the case drill two holes on either side put a screw in each and pry out I went to home depo and got a pvc fitting that was the same size as the seal and a square plug to screw into the fitting to hit with a hammer to set the seal oil the rubber on the seal first and take some fluid out of the case first lol
 

antfarmer2

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The seal that is leaking if the oil from the hydro is getting to the chain case is a easy Fix on my 743 seals were 16 bucks get to the drive motor take off and cap off lines and nips to keep crap out take off motor there is the seal on the case drill two holes on either side put a screw in each and pry out I went to home depo and got a pvc fitting that was the same size as the seal and a square plug to screw into the fitting to hit with a hammer to set the seal oil the rubber on the seal first and take some fluid out of the case first lol
Sorry on that seal just need a screwdriver to pry the seal out
 

Tazza

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Sorry on that seal just need a screwdriver to pry the seal out
The drive motor isn't really sealed, if it's the same type as they use on single speed machines. The end where the shaft comes out is made to be able to wobble, there is no seal here, the seal for that is at the chain case, this is the seal they will need to replace.
Not sure about all the removing they speak of, i know other smaller machines, you remove hoses, a few bolts and the motor is off.
 
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Mikej

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The drive motor isn't really sealed, if it's the same type as they use on single speed machines. The end where the shaft comes out is made to be able to wobble, there is no seal here, the seal for that is at the chain case, this is the seal they will need to replace.
Not sure about all the removing they speak of, i know other smaller machines, you remove hoses, a few bolts and the motor is off.
Took machine back to dealer to have seal fixed. They replaced seal on side with new drive motor, put it all back together and ran it around their yard for a while, checked chaincase oil level and determined that other seal must be leaking too, tore apart again and changed other seal. Total labor was 28 hours. WOW. Thought maybe they should have either checked both sides before tearing down by isolating each motor and running, or just changed both seals while in there the first time. Told me the back pressure from having a plugged case drain filter from motor failure caused the seals to leak. ??? Thats a lot of back pressure. In the end I only paid for part of labor but lots of traveling and missed revenue. Hope it is fixed now.
 

Tazza

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Took machine back to dealer to have seal fixed. They replaced seal on side with new drive motor, put it all back together and ran it around their yard for a while, checked chaincase oil level and determined that other seal must be leaking too, tore apart again and changed other seal. Total labor was 28 hours. WOW. Thought maybe they should have either checked both sides before tearing down by isolating each motor and running, or just changed both seals while in there the first time. Told me the back pressure from having a plugged case drain filter from motor failure caused the seals to leak. ??? Thats a lot of back pressure. In the end I only paid for part of labor but lots of traveling and missed revenue. Hope it is fixed now.
That's just silly, i can't see that taking them 28 hours..... Generally when one seal goes, they both get replaced for good measure, no stuffing around.
Back pressure from a plugged case drain can and does make seals fail. It's a shame they didn't do both seals straight away and be done with it.
Hopefully it's fixed for good now.
 
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