4500D vibration in drive very sluggish Cancel The title field is required!

1. Sean Donnelly

   

   8 posts
   
   6/7/2018 7:06 AM

   Well another problem with this machine Toro 4500D with 3631 hrs. Fixed the PTO problem with adding a ground into the system. Worked flawlessly for about a month. Now the machine will not travel forward or reverse unless under full throttle and struggles to do so. Operator said all of a sudden problem arose with no other symptoms. The 4wd 2wd is not switching back and forth and it seems like hyd flow is being restricted. Lift, blades and steering all work as they should. I swapped the electric coil on the 4wd manifold with a known good one and tested for 12 volts at the connection and was good. There also seems to be a vibration in the hydraulic system when the machine moves.
   
   One interesting thing to note. The previous mechanic used bio syn extra hydraulic oil changed at 2887. Then at 3200 the oil was changed to Napa aw46 and 48 oz of Lucas trans fix was added. I questioned this to the superintendent and they were searching for answers on the PTO issue. He told me Lucas was added because it was an older transmission. I do not know if this product is compatable with this system. Once the problem is found I will be flushing the system.
   
   Another thing I do not know if is related or not but I have replaced many hyd hoses recently on this unit so possibly contamination in the system?
   
   I have read though the service manual and purchased a hydraulic pressure tester. . I tested circuit charge pressure first and was within spec. Next I checked traction circuit relief pressure and only read 1000psi forward and 1200 psi reverse. Service manual states 5000psi needed. I checked the relief valves in pump and seem fine. I could not find a test for the front wheel motors. Is there a way to test the motors?
   
   Any pointers on this problem would be helpful.

   
   
   
   
2. Sean Donnelly

   

   8 posts
   
   6/13/2018 2:06 PM

   Continuing on this problem. I fixed the 4wd coil by replacing the solenoid valve (SV) on the 4wd manifold. This corrected the 4wd not working but the machine is still sluggish in 4wd and 2wd and PSI at test ports is about 1000 forward and reverse on the ground under load. I also removed cleaned and swapped out PD1 valve PD2 valve RV5 valve CV valve in 4wd manifold with working units from my other mower with no change. I removed and checked the three CV in filtration and charge control manifold as well. I also checked the check valve in the pump in forward and reverse direction.
   
   I tested the wheel motor case drains as well. Full throttle sitting on the machine the right wheel motor produces about 1/2 gallon of fluid in 30 seconds. The left wheel motor produces next to nothing. I tested my other machine and that one produces almost exactly the same and works fine (over 5000 hrs). On both machines if I raise both wheels the right one sitting on the machine travels faster in both forward and reverse. If I run my pressure tester on either the forward or reverse port with one wheel raised there is a slight vibration to start and I only get a reading of 500psi. I can turn the wheel that had the most fluid come out slightly easier than the other one on both machines if I jack it up in the air. If a wheel motor was bad would pressure be ok in either forward or reverse? Are there any either tests for wheel motors? I have not found anything in the service manual on this.
   
   The machine does move but does so very slowly and needs full throttle to climb the smallest little incline. Anyone know if there are any way to check the pump for pressure before the ports in the system? Anyway to adjust the pump pressure in the pump so it comes closer to the relief of 5000? Pump from Toro is $3505. Not available aftermarket. Anyone ever rebuilt one of these pumps?
   
   Any help would be appreciated.

   
   
   
   
3. Zachary Hill

   

   1 posts
   
   7/10/2018 7:07 AM

   I would defiantly double check your hoses that were replaced if they are in the wrong spots it can create vibration/flow issues/wining ect.
   
   also have you tried to adjust your relief to the proper specs? if it cannot be adjusted to meet spec then I would suspect the relief valve only after verifying system pressure is available from the pump.