2002 425 Rear Wheel Motor

   / 2002 425 Rear Wheel Motor #1  

ahartman

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Sep 25, 2008
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4
Before everyone links me to the myriad of older posts about the topic, let me say I have searched and read a number of them. It's been mind blowing with the different years, sizes, upgrades, etc. With that said, I replaced one years ago. I tried to do it locally, but ran into so many size issues (actual size of motor which wouldn't fit into the housing) that I eventually shelled out the cash for a new one from Power Trac. I've learned and have read here that Power Trac tends to mark up their parts fairly significantly. So, does anyone know the following?

- Should I rebuild or buy a new wheel motor?
- What is the model/parts number for a rebuild kit or motor?
- Where is the best place to purchase?
- With a limited budget, should I consider replacing all of them with "superior" motors that may give me more torque? Costs?

Thanks in advance! I love this forum!
 
   / 2002 425 Rear Wheel Motor #2  
Before everyone links me to the myriad of older posts about the topic, let me say I have searched and read a number of them. It's been mind blowing with the different years, sizes, upgrades, etc. With that said, I replaced one years ago. I tried to do it locally, but ran into so many size issues (actual size of motor which wouldn't fit into the housing) that I eventually shelled out the cash for a new one from Power Trac. I've learned and have read here that Power Trac tends to mark up their parts fairly significantly. So, does anyone know the following?

- Should I rebuild or buy a new wheel motor?
- What is the model/parts number for a rebuild kit or motor?
- Where is the best place to purchase?
- With a limited budget, should I consider replacing all of them with "superior" motors that may give me more torque? Costs?

Thanks in advance! I love this forum!

I replaced one on my 422. I went to a local shop. They could get a new one for $305, six weeks delivery. They could rebuild it for $295. This was so expensive because there was corrosion where the front seal met the housing. They had to buy the rotor and front case. If I remember correctly PT wanted $310 for a new one. I got the rebuild from the local shop. The failure was just a leaking seal, I am guessing this was caused by corrosion. Maybe PT could have rebuilt it cheaper. Next time I will send it to PT for a rebuild. I am sure others can do better price wise because I was not real happy with the price. It has worked fine though.
 
   / 2002 425 Rear Wheel Motor #3  
Here's my notes from August 2009 after speaking with Terry at PT about a leaky motor on my 2006 422:

Repair of motor = $83.40 + shipping
New motor = $303.57

Call extension 250 for Parts Dept to get a RGA#

Don’t forget to seal/label hoses and motor.

Hope this helps!
 
   / 2002 425 Rear Wheel Motor
  • Thread Starter
#4  
So I have finally gotten around to repairing my wheel motor. Was pretty easy (assuming it doesn't leak when I fire it back up).

Question: How do I bleed the system? I've seen posts that say just start up the machine and let it idle for 20 minutes. Other posts say I need to bleed the system properly first. Ideas?
 
   / 2002 425 Rear Wheel Motor #5  
So I have finally gotten around to repairing my wheel motor. Was pretty easy (assuming it doesn't leak when I fire it back up).

Question: How do I bleed the system? I've seen posts that say just start up the machine and let it idle for 20 minutes. Other posts say I need to bleed the system properly first. Ideas?

You can bleed the system the same way you bleed it after a hydraulic filter change...

Note that you should fill the wheelmotor with fluid, as best you can, before connecting the hoses. You want to induce as little air as possible in the circuit.

Then, bleed it normally as above, start it and let it idle a few minutes, or slowly moving it for a few minutes, to make sure any remaining air bubbles have been purged, and you should be good to go...
 
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   / 2002 425 Rear Wheel Motor #6  
I an not so sure the normal bleed procedure will work.

The fluid goes through one wheel motor, and passes on to another wheel motor and back to pump in a closed loop.. If the wheels are sitting on the ground, no fluid is flowing through the wheel motor circuit.

I would guess in order to properly bleed the wheel motors, you would have to jack all four wheels off the ground and motor the engine over until you see no more air. That procedure is for the filter and pump to purge the air,

To remove any air from the wheel motors, you have to move the wheel motors. You will have to turn the wheels to let all the air out of the closed loop circuit.

My wheel motors have case drains, and some air might exit out of the drain.

I have never had to do this, but this is what I would do.

Fill the wheel motor by turning the shaft if possible.

Set up the bleed circuit an start the engine, and leave at idle and press on the pedal to turn the wheel motors until you see no air coming out the bleed tube. There should be very little pressure.

After all the wheel motors are turning equally, shut the engine down lock the bleed screw, and remove the jacks. Then start the engine and do a test drive.

You can put the front of the PT up against a tree and see if all the wheels spin or try stalling the engine.
 
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   / 2002 425 Rear Wheel Motor #7  
I would call Terry at Power Trac and see what he has to say. Then let us know.

Ken
 
   / 2002 425 Rear Wheel Motor #8  
When I installed four new ones, I had it on jackstands. Performed the normal bleed procedure, and then started it. Let it idle for a few minutes, checking for leaks, then applied tram. As soon as I applied tram, all four wheel motors started spinning. I ran it that way for a couple more minutes, again checking for leaks at low throttle, low tram. Then installed the wheels and took my first gentle test drive...

YMMV
 
   / 2002 425 Rear Wheel Motor #9  
Kent,

Was the bleed circuit open when you were turning the wheels, and if it was, could you tell if it was flowing a lot of fluid through the bleed tube?

Does your tram pump have two section in the pump each turning two wheel motors, or one pump turning four wheel motors, in a series/parallel configuration.
 
   / 2002 425 Rear Wheel Motor #10  
No, the bleed circuit was only open when I was actively bleeding it, by cranking the engine with the spark plug wires pulled off. I had to crank it more (in several short sessions to prevent overheating the starter) before it cleared the visible air bubbles/spurts out of the system, in comparison to a simple filter change. But, as I said earlier, I tried to keep all the hydraulic lines as full of fluid as I could while detached, and I filled the wheelmotors as full as I could before putting the lines back on.

I think that there was likely still some air in the lines when I started the engine, but because the wheelmotors were in a no load situation when I applied the tram pedal, that it wasn't noticeable, and quickly cleared whle running with the tram pedal depressed.

I think the only risk is potential cavitation of the tram pump, before the charge pump can replenish the system. I also think my tram pump is likely worn and requires continual replenishment any way...

As an example, I know for sure that mine will typically not kill the engine when it is in a situation where the engine is running fast, the tram pedal is depressed, and the wheels aren't turning (like pushing up against a tree). Instead it just slows the engine down and whines. That tells me that pressure is being relieved somehow, somewhere...

In comparison I've had the main PTO kill the engine more than once, acting like it was hydraulically locked. My drive system doesn't act that way. So, it must be leakage or bypassing somewhere...

Mine has a single tram pump.
 
 
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