Isaac 2 #1 Posted June 30, 2023 New to the group.. This forum looks like the most knowledgeable group of people on the Eaton model 11 transmission so I figured I’d ask here. my mower runs great and smooth until I get to a hill. The transmission whines and just won’t go forward anymore. So I tore my transmission apart expecting to see something obvious but everything looks surprisingly clean.. all the piston balls and bores mic out ok and everything looks to be in good shape to me. has anyone dealt with a problem like this and maybe has some insight on what could be the problem in the transmission? Thanks a lot Share this post Link to post Share on other sites
lynnmor 7,352 #2 Posted June 30, 2023 You can download a manual here. Hopefully you can find the answer you need in it. 1 Share this post Link to post Share on other sites
Handy Don 12,436 #3 Posted June 30, 2023 I hope you had the manual or some guidance before you started taking it apart. There are a number of tests to run before disassembly. Oil level? Correct hydro filter (i.e. without an overpressure bypass)? No obstructions in the lift/filter/intake plumbing? My first thought would have been to test that the charge pump was supplying oil to the lift circuit and that an adequate supply of oil was getting back to the motion pump input. Once apart, though, know that the pump and motor balls are all fitted--they MUST be kept in their original sockets to work properly. Also, a worn hydro will still look clean. Lastly, a slipping drive belt will easily emulate a failing hydro. 1 Share this post Link to post Share on other sites
Isaac 2 #4 Posted June 30, 2023 40 minutes ago, Handy Don said: I hope you had the manual or some guidance before you started taking it apart. There are a number of tests to run before disassembly. Oil level? Correct hydro filter (i.e. without an overpressure bypass)? No obstructions in the lift/filter/intake plumbing? My first thought would have been to test that the charge pump was supplying oil to the lift circuit and that an adequate supply of oil was getting back to the motion pump input. Once apart, though, know that the pump and motor balls are all fitted--they MUST be kept in their original sockets to work properly. Also, a worn hydro will still look clean. Lastly, a slipping drive belt will easily emulate a failing hydro. Thanks for the reply.. yes I am following along in a repair manual for this transmission. oil level is correct, I have the correct filter, and no obstructions in the plumbing that I can see. The oil was flushed and new oil was added when I first got the mower. I definitely should have checked my charge pump pressure before I took it all apart. I may put it back together to do that if I can’t see anything else it needs. when I said the hydrostat looked clean I just meant that there was no obvious scarring or worn parts. And I checked the belts as well. I watched the hydrostatic pulley while going uphill and there is no slipping. I appreciate your response and if I can’t find anything wrong I will put it back together and check the charge pump pressure. 2 Share this post Link to post Share on other sites
lynnmor 7,352 #5 Posted June 30, 2023 1 hour ago, Isaac said: oil level is correct, I have the correct filter, and no obstructions in the plumbing that I can see. The oil was flushed and new oil was added. I checked the belts as well. I watched the hydrostatic pulley while going uphill and there is no slipping. What filter do you have and who changed the oil? What kind of oil? Make sure the pulley is spinning the input shaft and not just slipping on that shaft. Is the motion control pushing the cam, on top of the transmission, all the way to the end of the slot? Share this post Link to post Share on other sites
Isaac 2 #6 Posted June 30, 2023 28 minutes ago, lynnmor said: What filter do you have and who changed the oil? What kind of oil? Make sure the pulley is spinning the input shaft and not just slipping on that shaft. Is the motion control pushing the cam, on top of the transmission, all the way to the end of the slot? Honestly this transmission isn’t in a wheel horse.. it’s in another mower but I wanted to ask here cause it seems like a bunch of guys know their way around them. I changed the oil and I used iso46 hydraulic oil. I used a Donaldson p551551 filter, it cross referenced with the oem filter. But yes all the linkage is adjusted and pushing the lever all the way forward and backward. Share this post Link to post Share on other sites
rmaynard 15,583 #7 Posted June 30, 2023 Was the oil that you drained the same as the oil you put back in? If not, then we Wheel Horse wrenchers would drain again and fill with 10W40 full synthetic motor oil. The proper filter for an Eaton 1100 is a Napa 1410. 1 Share this post Link to post Share on other sites
squonk 41,291 #8 Posted June 30, 2023 The transmission moving along and then whining at the hill eliminates key ways, pullies, linkage ect. Personally I would look for another pump or complete trans. I had the same issue on a C-145. Everything looked great but after it got hot a small hill would stop it. I replace the whole she-bang and it was great after that. Share this post Link to post Share on other sites
Isaac 2 #9 Posted June 30, 2023 34 minutes ago, rmaynard said: Was the oil that you drained the same as the oil you put back in? If not, then we Wheel Horse wrenchers would drain again and fill with 10W40 full synthetic motor oil. The proper filter for an Eaton 1100 is a Napa 1410. The service manual for this mower calls for sae 20 or 30w which I thought was odd.. okay I think I’m gonna put it back together to check my charge pressure and I’ll try a different oil. Thanks for the response Share this post Link to post Share on other sites
Isaac 2 #10 Posted June 30, 2023 22 minutes ago, squonk said: The transmission moving along and then whining at the hill eliminates key ways, pullies, linkage ect. Personally I would look for another pump or complete trans. I had the same issue on a C-145. Everything looked great but after it got hot a small hill would stop it. I replace the whole she-bang and it was great after that. I’ll keep my eye open for another unit. Thanks Share this post Link to post Share on other sites
Sailman 1,294 #11 Posted June 30, 2023 (edited) It is surprising what a difference a belt can make. On my GT 14 (sunstrand transmission) I had a similar issue with it not pulling up the hill well. I thought the transmission or pump must be bad. It had an after market belt that was supposed to be correct. I replaced it with an OEM belt, put a new spring on the idler pulley and it made all the difference! Edited June 30, 2023 by Sailman Share this post Link to post Share on other sites
Isaac 2 #12 Posted June 30, 2023 23 minutes ago, Sailman said: It is surprising what a difference a belt can make. On my GT 14 (sunstrand transmission) I had a similar issue with it not pulling up the hill well. I thought the transmission or pump must be bad. It had an after market belt that was supposed to be correct. I replaced it with an OEM belt, put a new spring on the idler pulley and it made all the difference! I’m starting to think the issue isn’t in the transmission because of how good it looks inside. So I’m going to reassembly and recheck everything including belts. Thanks Share this post Link to post Share on other sites
