X900 Hydro Transmission?????

[10-e-c-dirt]

Background, delivered 04/2015, 2200 hrs,14500 miles. Two minor probilems, broke headerpipe/muffler, stock fuelpump, (sraightout exhaust/electric fuel pump fixed it)
Use Kubota filters/SUDT fluid,

Two weeks ago, I changed all the fluids and filters, Everything worked as it should for 1 week.
3 days ago it started jumping under lite throttle when pulling out, if I floor board it works fine. Just starting out, jump/stop, jump/stop, jump/stop. Putting in 4WD makes no difference. This happen all at once, not gradually getting worse.

Got in in my shop, up on 4 jack stands. Under no load, wheels turn normal. All CV joint seam tight, turning by hand everything seams tight, no noticeable play.
I do have several control arm bushings/hub bushing that are going to need to be replaced soon. Would that be the problem???
Anyone got any idea.
Thanks
TennesseeDirt
BTW, dont ask me if its makeing a noise/clicking, I'm very hard of hearing, damn near deaf ! LOL
thats why I put a staightout exhaust on it, I can't hear it...

 

[bordercollie]

Hi , make sure all of the fluid reservoirs are full. There were some newer models that had poorly labeled reservoirs . I don't remember which models gave such fits but sure caused some owners great aggravation and transmission woes after running them dry . These fill up areas were different from those in the past so fooled old owners of the RTVs. If I remember right, one for the transmission was under the seat yep .. very unlike the old reservoirs . Don't use it till you check the fluids just in case. Best of luck to you !

 

[10-e-c-dirt]

All fluids are at the proper level.

 

[10-e-c-dirt]

Well, it looks like I've got major problems. While the RTV was up on the jack stands, I noticed that the bracket holding the hydraulic tank was broken and to get a good weld on both sides, I needed to drain and drop the hydraulic tank. On my first hydraulic oil change back at about 400 hours or whatever the manual said. I put a magnet in the bottom of the tank. After I got the tank out and checked the magnet, it was absolutely covered up with metallic shavings. So where do I start? And this might be above my pay grade. What's the first thing to pull and check for wear? I have no idea which of the 3 return lines to the tank that the metal shaving came from. I've still got the filters that I changed out 2 weeks ago, I'm planning on opening the suction filter and see if there's any metallic shavings in it. BTW, I do have the proper oil filter can opener type tool that I bought in my old racing days from Summit or Jegs. So where do I start? I'm assuming the jumping problem I'm having is because of the metal shavings!

 

[Doc]

I'm not the one who can advise but I do wish you luck. Like you said it does sound major.

 

[RodRocket]

I guess after a week you have had this problem investigated and on the way for likely repairs.
BTW, not all contaminates found in the reservoir and/or filters may necessarily come from the actual closed hydraulic loop, that from the pump (pistons, swashplate or valve-plate), and the output motor. There are other mechanical components in the system that can fail and break and end up in the filters, etc. and can be repaired without serious major costs, hopefully!
The most fundamental and biggest arch enemy for hydrostatic transmissions (and all hydraulic systems) is contamination. Having and maintaining absolutely clean oil is the number one objective to focus on.
In reality, it is the fine particles that can do the most damage, as they can get into the very close tolerances associated with hydrostatic transmissions, which compound the ongoing wear problem. With luck, the bigger contaminates get caught by the filters or sit on the bottom of the reservoir, and not remain suspended in the oil.
When a hydrostatic transmission has tended to fail, one of the first components to inspect after stripping is the pump valve-plate (piston timing/distributor plate). If any scoring can be seen or felt with a finger nail, it is not good news. Yes, fine scoring can be ground or lapped out, but if not. well . . . . .
The three golden rules for hydrostatic transmissions is clean oil, clean oil and really clean oil.

 

[aurthuritis]

probably a thrust bearing failure.