Bobcat 743 Right side has no drive

[Bobcat743Help]

Hey guys I have a Bobcat 743 and a couple weeks ago it lost all power to the right side. My dad was driving it and said it just made a loud pop or bang than lost all power to the right side. I thought it was just the drive motor so I took that apart and found out that the coupler that connects the linkage key was broke in half. I got a new drive motor and I still have no power to that side. I put it up on jack stands and when I try to turn the tires by hand the right side moves free in both directions, but the left side does not move in either direction. When I give it power both sides work in both directions, but the right side moves noticeably slower than the left side in forward and reverse. I already check linkage, lines, and chains but haven't found anything. What other things should I check. Anything Helps Thanks!

 

[yellow350z]

So nobody replied ? im having the same issue, did you find your issue yet ?

 

[flyerdan]

So nobody replied ? im having the same issue, did you find your issue yet ?

The 743 has a gear reduction box between the motor and the chain array; if you can turn the wheels and you know that you have a good motor, that would likely be the culprit. If you can stop the wheels when they are being driven while up in the air, that would indicate a gearbox problem.
There are a few 743 books in the manual thread, or you can get a breakdown on the bobcatpartsonline site to see how everything relates to each other.

 

[Bobcat743Help]

The 743 has a gear reduction box between the motor and the chain array; if you can turn the wheels and you know that you have a good motor, that would likely be the culprit. If you can stop the wheels when they are being driven while up in the air, that would indicate a gearbox problem.
There are a few 743 books in the manual thread, or you can get a breakdown on the bobcatpartsonline site to see how everything relates to each other.

Okay thanks for the advice, that's what I was thinking after some more research. I will be taking the drive motor off today and taking a look at the gear reduction box gears. I will keep this updated to help others with the same problem also. Thanks! Also if anyone knows how to post pictures on here I would love to be able to post some pictures of this all to help also.

 

[Bobcat743Help]

Okay thanks for the advice, that's what I was thinking after some more research. I will be taking the drive motor off today and taking a look at the gear reduction box gears. I will keep this updated to help others with the same problem also. Thanks! Also if anyone knows how to post pictures on here I would love to be able to post some pictures of this all to help also.

Just got the drive motor taken off again and pulled the seal to take a look at the reduction gears. Both reduction gears are still in contact with each other, and cannot see any problems with the reduction gears. What are the next things that I should check? At this point I am thinking it must either be a bad drive motor, a problem with the pump or some sort of relief valve somewhere that is stuck. I think I am going to have to go buy or borrow a pressure tester to check the pressure unless there is something else I am overlooking or missing. If anyone has any suggestions to check anything else or other possible causes that would be greatly appreciated. Anything helps, thanks.

 

[Tazza]

Just got the drive motor taken off again and pulled the seal to take a look at the reduction gears. Both reduction gears are still in contact with each other, and cannot see any problems with the reduction gears. What are the next things that I should check? At this point I am thinking it must either be a bad drive motor, a problem with the pump or some sort of relief valve somewhere that is stuck. I think I am going to have to go buy or borrow a pressure tester to check the pressure unless there is something else I am overlooking or missing. If anyone has any suggestions to check anything else or other possible causes that would be greatly appreciated. Anything helps, thanks.

The gears may look good, but it's possible the shaft between it and the internal sporcket was bad.
I wonder if you can wedge something soft into the gears to stop them moving, then try turning the wheels, see if they still turn, if so, it could be a broken key that transfers power from the gearbox to the sprockets in the chain case.
It almost makes me think of a broken weld or key as you do get movement, but not getting the power transmission it should. Something is slipping.

 

[Bobcat743Help]

The gears may look good, but it's possible the shaft between it and the internal sporcket was bad.
I wonder if you can wedge something soft into the gears to stop them moving, then try turning the wheels, see if they still turn, if so, it could be a broken key that transfers power from the gearbox to the sprockets in the chain case.
It almost makes me think of a broken weld or key as you do get movement, but not getting the power transmission it should. Something is slipping.

That's what I was thinking also. I wedged a rag in-between the gears and tried to turn the wheels. I had no movement. I am going to pressure test the pump tonight and I will let you know how that goes. If it fails is there any valves I should check before I start to looking into the pump? Is there a way to test the valves alone or how could you test those. Could I just switch the valves around from the other side to test them? If anyone else has any feedback that would be great. Thanks!