Jovee Posted May 11, 2011 Posted May 11, 2011 I started to have some drive problems with my 5212 last fall and initially thought it was my imagination. The local yards I mow are hilly and there is usually something that hinders progress. This year though it is apparent that I do have a problem with the hydro and am wondering if there is a fix or it's going away on me. When I push the lever to forward to climb a hill it almost doesn't want to go. If you start it at a crawl and incrementaly push the lever it will slowly gain speed. It functions somewhat normal on level ground though. It got to one point last weekend where it virtually stopped on a hill. The belt does not appear to be slipping and is tight when engaged. Nothing is obstructing the belt path. The fluid is full. I thought of a filter obstructing the flow but if it has one either I can't see it or it's invisible. There is a low pitch howl that comes when the lever is pushed to the power position. It's been a great tractor and I'd hate to have something happen to it but I never worked on hydros or gearboxes before. Am I missing something or is it terminal?
TommyK Posted May 11, 2011 Posted May 11, 2011 Howdy fellow 5212 owner! Even with sufficient oil, if the internal moving parts of the pump and motor aren't sealing well enough you could get some internal by-pass, or "blow-by" in internal combustion engine parlance, to prevent the pump from developing enough pressure to move the tractor up a difficult grade or pull a significant load. The by-passing oil doesn't leak out, it just stays in the system. Like an internal combustion engine with worn rings, It may push a truck down the road on the flat just fine. But when lugging up a hill there might not be enough compression to make it all the way up. I, too, suspect when driving your SimpleCity to the gas station for a cold pop, top speed isn't what it used to be. Could be the hydro pump and/or motor are worn and need to be rebuilt or replaced.
dlkelley713 Posted May 11, 2011 Posted May 11, 2011 Jovee, You said that when you start slowly and incrementally push the lever forward it will slowly gain speed? What happens if you push it all the way forward quickly? Has your max ground speed slowed noticeably on flat ground? I assume you've checked the cage spring in the linkage to make sure it's decompressing? When you give it full forward (with engine off and seat lifted), does the cam rotate enough to get the plastic bushing to the end of the cam slot? Dan
Jovee Posted May 11, 2011 Author Posted May 11, 2011 When I push it all the way forward quickly, it just bogs and looks at me like I'm asking too much of it. I have not noticed any difference in level ground speed in max mode as I rarely get a place to do that. As far as the cam thing goes, I will have to check that when I get it back out. I know the one lever pushes back as far as the axle but I can't get to the other end at the moment. If it does or doesn't, what would that mean? The blow by theory that Tom mentioned is a plausible theory for how it acts. My 515 has been waiting about 7 years to be reassembled - maybe this will be an excuse-
dlkelley713 Posted May 12, 2011 Posted May 12, 2011 Could the extra torque created during faster (attempted) acceleration be causing the drive belt to slip? If the belt isn't slipping and the hydro lever and linkage is fully rolling the cam (and lever on the hydro) to the "full speed forward" position, then it doesn't sound good. Make sure you don't have a stuck brake... but you'd notice that on level ground I'm sure. Maybe something binding in the rear end? Do the wheels roll fine when in 'free wheel' mode? If all those things check out okay, then it might be time for a hydro-donating tractor... Dan
Jovee Posted May 12, 2011 Author Posted May 12, 2011 I have eliminated all of the obvious stuff and it does roll fine in free wheel. The belt is tight when engaged and I don't hear it or smell it at all. I am considering changing it as a last ditch effort only because I can't see it when I'm driving but it sounds like the prognosis is not good-
Jovee Posted May 22, 2011 Author Posted May 22, 2011 Just an update on the problem I had - Turns out the $45 drive belt cured the symptoms :). The only thing I noticed with the old belt was that the V was worn a little narrower than the new one. I guess that was enough to make the difference. sm01sm01
dlkelley713 Posted May 23, 2011 Posted May 23, 2011 As painful as $45 is for a belt, it sure beats replacing the hydro! Thanks for letting us know - it may help someone else down the road. Dan
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