I have had this unit for 16 years with no problems, I have done the general maintenance to keep the machine nice. The problem started last year when you tried to make a right turn, the unit would jerk, not turn smooth. This month we had a bad storm and when I tried to move some small tree's from the road the unit jerked and at one point seemed to lock up on the right side. I could hear the hydraulics and they sounded like they were loaded up but not moving. I put the unit on blocks and removed the wheels, there is very little slack in the chains and the axles are not in a bind. Where else should I be looking, drive motoe or pump?
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7LBSSMALLIE
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proper diagnostic would be to cap stat and stall, if it sounds good and by that it screams, stat good(probally) most efficant is tear down motor, and inspect if good youre only out a seal kit and could use it anyway. but the usual sympton of bad seals is loss of drive or weak in one side one direction only. most likely are carrire brgs after motor removed a visual inspection should reveal , in layman terms pull suspect motor ,look at carrier brgs shake push pull and pry. if looks bad it is. but seal the motor while on bench pay attention to timing of motor , hose swap not an option here.
Ok I pulled the right side mptor and sent it to be rebuilt, was told it would be 2 weeks. If i'm reading you right, you are saying cap the hose's to the right motor and start the engine, applying forword or reverse to the right stick the hydraulics should scream and this would be good ?. Would this tell me if my replenishing valves are good or bad ?
is this correct
That is just a quick go or no go test. It will not tell you what pressure it is putting out or the flow it is doing either. This means one side may have more power than the other or it may move faster than the other. It just confirms that the pump isn't totally dead and generating pressure that will load the engine down.
7LBSSMALLIE
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radial axial piston pump failure is rare..plastic seals in motor common.. usually indicatted by weak drive one side. please remove motor tear down inspect ...
ok mech. called today and said he could not find anything wrong with the motor. he said everything looked real good,he is putting it back together with a new seal kit and that my problem is elsewhere ?
Just how much checking have you done on the chain case? If there is a bad tooth on a sprocket it could do this too. Bad bearing in the drive motor carrier.
It is always possible you have a pump issue. If the issue is not fixed, swap drive motors over, see if the problem moves. If not, it is the pump or a chain/sprocket.
I got the motor back and installed, drive gears,bearings, chain all look good. still have the same problem. swaped motors from side to side, problem remains on right side. removed and replaced replenishing valves, still no drive on right side. where do I go from here ?
If the problem is still there, and you swapped motors it's time to upll the pump.
The innards of the pump are not complicated at all. I believe the pump that drives the right side is the front section that the hydraulic pump bolts to. Give it a good clean and open it up. Check for wear on the wear plate and check the rotating group for damage.
Remove all 4 relief/replenishing valves, make sure the springs are not broken.
Rotating groups and wear plates are not that expensive is one is bad.
OK just got pump back from the shop, both drive pumps are good, put unit on test stand and they test out good. The aux. pump is weak and I will replace later, this has nothing to do with the drive. All that is left to check is the gearbox, right. If so I will pull it, but I do not hear any gear noise or grinding, at a loss hear
SkidRoe
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Just a slight correction: I would not be so quick to say that the aux. pump has nothing to do with the drive. The aux. pump is utilised to generate charge pressure for your hydro system, and replenish any hydro fluid lost through the motor case drains. Now, the pump would have to be pretty knackered to not provide enough flow / pressure to perform this function, and you definitely would have a low charge pressure warning light if this was the case.
Wirenut2266
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I was wondering bout that charge pressure as well? All that is left if for sure not sprockets/chains/motors is pump and aux. pump????? Time to get the popcorn, this could get interesting. Sorry bout your troubles though...
I don't believe the 743B has a gear box, it is just a motor carrier.I was wondering bout that charge pressure as well? All that is left if for sure not sprockets/chains/motors is pump and aux. pump????? Time to get the popcorn, this could get interesting. Sorry bout your troubles though...
As you have had the motor checked and the pump too, it has to be a chain or sprocket. Remove the inspection cover, jack it up and move the wheels so you can check every part of the chain and sprockets. The hear ones will be hard to see though.
I had a chain once that one of the rollers had opened up, no idea how. I got my torch, heated it and closed it back up. It may be something as simple as this. Only one roller out of 20 odd feet of chain.
The aux pump on the test stand would only reach 650lb. would'nt this effect the drives on both side's, not just one side. the only side effected is the right hand side ,if you were sitting in the seat, this is the drive that the aux. pump bolts to.
SkidRoe
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Thinking out loud:
What if the charge pressure was only reaching one side? I know that there are some little bronze filters inside / behind some of the hydro fittings (seen other posts talking about them). If your aux pump has that much wear in it, that metal would have to have gone somewhere, logically, these filters would have collected some of it.
Dunno, just hypothesizing.
Even if the pump pressure is that low it only needs about 100 lbs for charge pressure to the hydostat pumps. I don't know if you have a square port block on top of the pump or not but if so that is where the bronze filter would be. Behind the center hose.Earlier models had it but yours may not have the port block. However that would affect both sides. Did the motor operate smoothly without the chain on it?
Jerry When I got the motor back from the shop I installed and put the unit up on stands to adjust the nuetral position.Both sides ran in forword and reverse while I made my adjustments. Thinking my problem is fixed I dropped the unit on the ground and found that the right side has no drive, you can feel like it wants to go, but not.At this point I put in new valves in the pump, same results. I pulled the pump and took it to a hyd. shop, they put it on the test stand, both drive pumps will go to 4500 lbs, but the aux would only reach650 lb. So I'm thinking the only thing left is the gearcase, I realy dont want to pull it if I dont have to, but I dont know what else it could be?
SkidRoe
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Did they bench test the motors? Could it be that the motor was assembled incorrectly?
