oil leak from drive motor

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Sx200

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after using my 643 for about 20 mins i noticed oil on the ground so i stopped and looked for the source of the leak, behind the front left wheel is the hydrostatic motor, and oil was coming from where the motor joined the body (transmission case). i'm sure its hydraulic oil not gear oil. it has been using quite a bit of hydraulic oil the past few times i used it but i couldnt see any leaks so could it have filled the transmission case? looking at the manual the hydrostatic motor has a million parts so is there a quick seal replacement or do i have to strip it all down? would this be the motor thats leaking or could it be any motor and this one has a broken seal so thats where the oils leaking from?
 

Tazza

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opps 632 not 643? dont know where i got that from :-?
I don't think there is any easy way to work out what motor is leaking, it looks like you will need to remove both motors and run then outside the machine to test them.
When you work out what motor is leaking, make sure you replace all the seals and O rings, its not a job you want to do twice.
Also, set your machine on level ground, then remove the plug from the front of the chain case. The oil level should be level with the bottom of the hole.
 

Sx200

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I don't think there is any easy way to work out what motor is leaking, it looks like you will need to remove both motors and run then outside the machine to test them.
When you work out what motor is leaking, make sure you replace all the seals and O rings, its not a job you want to do twice.
Also, set your machine on level ground, then remove the plug from the front of the chain case. The oil level should be level with the bottom of the hole.
is there any special tool needed? is it a "go by the service manual"? and replace all seals?
 

Tazza

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is there any special tool needed? is it a "go by the service manual"? and replace all seals?
From what i see in my manual, there are no special tools needed (i think most motors are basically the same).
Just keep in mind that you need to keep it clean!. I have never pulled a motor apart before, but from the diagrams they look fairly simple. Just take note of where parts go and what way, as they have worn in and you want to put them back in the same way.
Worst case, you still have a spare motor that will show you how it all goes back together :)
 

sterlclan

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From what i see in my manual, there are no special tools needed (i think most motors are basically the same).
Just keep in mind that you need to keep it clean!. I have never pulled a motor apart before, but from the diagrams they look fairly simple. Just take note of where parts go and what way, as they have worn in and you want to put them back in the same way.
Worst case, you still have a spare motor that will show you how it all goes back together :)
I recently pulled a motor on my 630 it is possible without splitting the chain pull the front sprocket off and the motor comes out putting it in is tough without pulling the axle out a little to line the sprocket with the axle but doing this makes the seal come out of the tube if you make shure to put the seal back in it isnt all that bad .....well as long as you can get it to the garage mine was 200 feet behind the shed in the dirt downhill good luck Jeff
 

Sx200

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From what i see in my manual, there are no special tools needed (i think most motors are basically the same).
Just keep in mind that you need to keep it clean!. I have never pulled a motor apart before, but from the diagrams they look fairly simple. Just take note of where parts go and what way, as they have worn in and you want to put them back in the same way.
Worst case, you still have a spare motor that will show you how it all goes back together :)
ok i pulled both motors out, replaced all seals on left hand side motor and just the outer seal on the right hand side (wasnt confident to take it on twice). put everything back together and when i push forward with the left hand the bobcat goes backward!!!!!! lol funny at first..... is this to do with the timing of the geroler? is the simple fix, to change the 2 hydraulic pipes to the motor? or do i have to take it out and start again? what a horrid job. looks like 2 chains 4 bolts and 3 pipes, but never struggled as much with somethin in my life, if id only got the money to send it away...lol
 

Tazza

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ok i pulled both motors out, replaced all seals on left hand side motor and just the outer seal on the right hand side (wasnt confident to take it on twice). put everything back together and when i push forward with the left hand the bobcat goes backward!!!!!! lol funny at first..... is this to do with the timing of the geroler? is the simple fix, to change the 2 hydraulic pipes to the motor? or do i have to take it out and start again? what a horrid job. looks like 2 chains 4 bolts and 3 pipes, but never struggled as much with somethin in my life, if id only got the money to send it away...lol
It will be the timing, i think i have details here on what to do, its for a different model, but i think they will be the same motor. I will try to take some pictures tomorrow of the book, but i am a tad busy at the moment... sorry, getting ready for a buddies wedding on saturday, ooh the joy!.
I totally agree that its a horrid job, i just yanked out the hydrostatic pump out of a 743 that “fell off the back of a truck” no really it did, i had never seen 2 snapped lift arm rams on a machine, now i have.....
The right hand lever shook violently when you try and start it. They aren't that complex, just murder to get to the nuts on the hoses. Just like the motors, and the hoses are thick and hard to move.
Worst case, take the motor and seal kit to bobcat, and get them to assemble it, its cheap so i was told, about 35 bux (this is in australia). They will time it correctly, as they will have had heaps of practice!!!
 

Tazza

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It will be the timing, i think i have details here on what to do, its for a different model, but i think they will be the same motor. I will try to take some pictures tomorrow of the book, but i am a tad busy at the moment... sorry, getting ready for a buddies wedding on saturday, ooh the joy!.
I totally agree that its a horrid job, i just yanked out the hydrostatic pump out of a 743 that “fell off the back of a truck” no really it did, i had never seen 2 snapped lift arm rams on a machine, now i have.....
The right hand lever shook violently when you try and start it. They aren't that complex, just murder to get to the nuts on the hoses. Just like the motors, and the hoses are thick and hard to move.
Worst case, take the motor and seal kit to bobcat, and get them to assemble it, its cheap so i was told, about 35 bux (this is in australia). They will time it correctly, as they will have had heaps of practice!!!
Ok, i have scanned the pages from my manual that shows how to set the timing of hydrostatic motors. I hope this helps you out.
http://users.tpg.com.au/tazza_/hydromotor/Untitled1.jpg
http://users.tpg.com.au/tazza_/hydromotor/Untitled2.jpg
http://users.tpg.com.au/tazza_/hydromotor/Untitled3.jpg
http://users.tpg.com.au/tazza_/hydromotor/Untitled4.jpg
http://users.tpg.com.au/tazza_/hydromotor/Untitled5.jpg
 

sterlclan

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Ok, i have scanned the pages from my manual that shows how to set the timing of hydrostatic motors. I hope this helps you out.
http://users.tpg.com.au/tazza_/hydromotor/Untitled1.jpg
http://users.tpg.com.au/tazza_/hydromotor/Untitled2.jpg
http://users.tpg.com.au/tazza_/hydromotor/Untitled3.jpg
http://users.tpg.com.au/tazza_/hydromotor/Untitled4.jpg
http://users.tpg.com.au/tazza_/hydromotor/Untitled5.jpg
the hoses on my machine were oppisite from each other and when I put the motor in i had to reverse the hoses on the one i replaced way easier than pulling the pump again good luck Jeff
 
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