EJL 5 #1 Posted April 20, 2022 I have a 518 with an Eaton 700 that has an issue with non-smooth transition from a full stop position to moving forward. As I move the motion control lever forward the motion is very jerky for a few seconds until it is moving at a constant speed, and while making this jerky motion it also makes a loud whining noise. Other than this jerky transition the machine runs fine and the jerky motion seems to have no impact on the overall operation. It might seem that changing the oil in the transmission & transaxle would be a good place to start, but the documentation I have read indicates that the transmission oil should not be changed (perhaps lifetime). Has anyone had this issue, or have any ideas for a possible solution? Can someone explain the relationship between the transmission & transaxle on this type of hydro drive system. Thx, John 2 Share this post Link to post Share on other sites
JoeM 7,986 #3 Posted April 20, 2022 (edited) John welcome to RS, The very first step in this process is to ensure there are no mechanical problems. Loose bad wheel hubs. keys. etc. Having someone drive the machine and observe the axle in the center of the hub those axles should move as one with the hub. Can even chain it to a object and put it under a load. Also take off the cover and clean around the linkage and make sure proper operation. If you suspect the hydro being a problem. The Eaton 700 uses two complete separate compartments for oil and lubrication. The hydro has its own reservoir, (located on top of the hydro pump), and recycles a small amount of oil (about a quart of 10w-30) through the pump and back to the reservoir. The gear drive area is separate and the oil there is splashed and tracked through the case to lube the gears/bearings. (As a note; the Eaton 1100 combines these two functions and uses a common sump oil for both hydro and gearcase. With the hydro oil being filtered) Getting back to your issue. I have found the oil used in the hydro will in time get water and contaminated. When you open the cap on the reservoir, the oil will look good but lurking below they can have moisture. You can change the oil in the Eaton 700 hydro but it is not easy. On the bottom side of the hydro pump is a o'ring plug. The plug is not easy to get to but can be removed. I included a pic of this plug. location etc. I made up a thin wrench but a chisel and hammer offering a few taps will loosen the plug. Once it is loose the o'ring plugs screw out pretty easy. If your oil looks like this, I would change it twice and change it after It is warmed it up. Hope this helps. Bad oil from Eaton 700 The dirt on the side of the container was there just showing the oil in the bottom of the pan. This oil came out of a 1000 plus hour hydro. Plug location. Plug removal Draining note the water in oil. Plug removed Edited April 20, 2022 by JoeM 3 1 Share this post Link to post Share on other sites
ebinmaine 71,092 #4 Posted April 20, 2022 @JoeM If the existing drive system proves not repairable can this be retrofitted to an Eaton 1100? 1 Share this post Link to post Share on other sites
JoeM 7,986 #5 Posted April 20, 2022 3 hours ago, ebinmaine said: If the existing drive system proves not repairable can this be retrofitted to an Eaton 1100? Yes, but the easiest swap would be to have a complete rear end assy. The reason is the plumbing with the filter assy for the charge circuit on the 1100 is needed. As a bonus, it would be a great opportunity to install a hydraulic lift. This would require the valve, cylinder, hoses and the rock shaft that accommodates the attachment of the cylinder. A doner roller works nicely in these cases. One nice thing is the hydro control linkage will work with a little adjustment. Eaton 700 Hydro Linkage. Eaton 1100 hydro control linkage 4 Share this post Link to post Share on other sites
EJL 5 #6 Posted April 20, 2022 Joe thanks for the feedback provided and the pics. I will dig into it and see if I can find a solution to my problem. John 3 Share this post Link to post Share on other sites
davem1111 2,091 #7 Posted April 20, 2022 I agree with everything Joe said, and I am positive that he has much more experience than I do with these hydros and transaxles. However, I do have a recent Eaton 700 experience that I think is worth sharing. I'm hoping you can solve your problem with just a drain and refill of the hydro, but if that doesn't work, some of this may help. I have a 312-A that had gradually, then completely, lost any movement from the hydro. I got a used replacement pump, pulled the old one, and mounted the new one. I filled the oil reservoir and let it sit for a few days. Some oil went in but not much. I tried turning the pulley some, off and on, and a little more oil went in. After about a week, I fired up the engine and engaged the pulley - nothing. Some helpful people here, and mostly @Handy Don suggested that maybe the pump didn't actually have enough oil in it and that expecting to fill it from the reservoir might not work. I removed the pump again, and removed the small drain plug on the bottom next to the large plastic one (that one is stuck on mine so I left it alone). Drained the pump, and only about a half cup of oil came out along with a little water. I left it to drain for a few days (probably overkill but I had other things to do). Then (and I think this is the important part...), with the reservoir attached and closed, I turned the pump upside down and started adding oil through the small drain hole with a funnel. Every so often, I turned both the pulley and the drive gear, and more oil went into the pump. After repeating this process for a while, it seemed that the pump was not going to take any more oil so I replaced the plug and re-installed the pump on the tractor. Voila! It works now. Note: It was a pain removing the original pump, mainly because the gasket had become more like a "weld". I had to use a very hard steel blade slipped into the gap where the gasket is and hammer on it carefully for a while before it would separate. If you're going to try this approach, order a new gasket in advance - it took about 10 days to get mine. Good luck! The thread about my hydro is here: 3 Share this post Link to post Share on other sites
JoeM 7,986 #8 Posted April 20, 2022 5 hours ago, davem1111 said: the pump didn't actually have enough oil in it Great point, but before you take the pump back off, I would remove the top fitting and try to fill without using the reservoir. The top fill and the bottom drain are both in the same cavity. Sounds like she was air locked??? 1 Share this post Link to post Share on other sites
