You are correct that "purging" means bleeding out the trapped air. My guess for deleting the text from the OM which would cover the purging procedure is this: The trend to consider the OPE hydrostatic drive units as "maintenance free, non-serviceable" components has reached the point where the OEM tells the consumer that the transaxles CANNOT be serviced, nor can the hydro oil be changed. After the OEM having stated that, there would be no reason for including any text covering purging of air because the only way air can find its way into the oil pump and hydro motor is for a significant volume of the oil to be lost from the transaxle, either by draining or from an oil leak. There has not been a "change of design" that eliminates the requirement to purge a hydro of trapped air, the OEM is simply trying to "down play" any references to a maintenance procedure by not mentioning it in the owner's manual. As to "not purging" a new unit prior to service, that unit would have been purged at the "factory" and would not require any additional purging afterward. BUT......if the consumer wanted to change the oil at 200 to 300 hour intervals, purging would certainly be required before the initial post maintenance use of the tractor. The purging procedure for other (older models) will work for all hydros, even if the OEM wants to play the Ostrich game.

Your machine has a 15 AMP charging system, so at high speed, you should have sufficient current. Headlights & fuel solenoid will use around 5-6 AMPs and PTO probably around 3-4? HOWEVER- IF the battery is low in charge, it may "suck" a higher than normal amount and thus drop the voltage to the point that the PTO disengages. I would start off by fully charging the battery and see if that resolves the problem (at least temporarily). IF the battery is 2 or more years old, I'd definitely get it load tested. As a matter of course, you should ensure that the connections to the PTO SWITCH and PTO are good. You should unplug/plug a couple times to "wipe off" any "crud".

Thanks to this Thread I was able to repair the LT180 I just bought at an auction. All was good until about 30 minutes of mowing when the world stopped turning and the machine was barely moving. After reading all the info above I took a slightly different approach to remedy the slow trans-axle condition. Taking the least aggressive path, I was curious if just a fluid change would make a difference, I decided to jack the rear end up and pop a couple drain holes into the Axle cast housing where Tuff-Torq suggests. Here is a Link https://www.tufftorqservices.com/EnvEEdefault/FlatHTML/TechInfo/ttcoil/pdfs/K46%20Drain%20Port%20Location.pdf I used a 1/8 stubby drill as not to injure any interior components, both holes drained over night. I then added 2 self tapping screws 1/2 inch long with a neoprene washer. Without the deck on the machine I was able to reach under the frame and pop the fill hole cover off using a stubby flat screwdriver. I cleaned up the magnet and filled the unit. 24 inches of 3/8 clear tubing and a small funnel allowed me to add back the 2 quarts of cheap 10-30 oil for my test. Popped the magnet and cap back in place and DONE! I am pleased that the result was success, the machine runs very well without growling and slowing after 30 minutes of use. My intention is to replace the 2 small drain holes with real drain plugs after about 5 hours of use and refill the unit with synthetic oil for hopefully many more years of use. Happy Mowing!!

I think that there are millions of people out there that don't have any trouble but also millions that end up scrapping their mowers because it is almost pointless to put them on Craigslist. Let's face it. There are a lot of people who should not be allowed anywhere tools or machinery. They never read Op Manuals, know how to use a grease gun or bother to change oil in their engine. They buy stuff, use it until it quits and then put it out at the curb for pick-up. They go back to the box store buy a new one and perpetuate the cycle. There are also people who think that a Deere lawn tractor is capable of the same work that a full-sized Deere Ag tractor is. They disregard the "lawn tractor" description and use it to jerk old shrubs and tree stumps out of the ground along with numerous other tasks that the tractor was never built to perform. The item that takes the most abuse is the trans-axle because that's what links the engine power to the ground. Someone figured out that average property owner puts 50 hours per year on their tractor. Ten years of average use equals 500 hours. The engines used in these tractors are supposed to give 1000 hours of use before needing rebuilding but that's based on the owner changing oil, filters and performing other routine maintenance diligently over that time-frame. The main problem with the low-end tractors these days is the hydro. The manufacturers decided to make the hydro's a sealed unit. Presumably, that was done to put an end to owners that put the wrong oil into the hydro's and also contaminated them with dirt and water out of sheer carelessness. Sounds like a plan but the only people it benefited were the hydro builders and the tractor manufacturers because of frivolous warranty claims. The problem with that idea is this. Thanks to time and heat, multi-grade oil begins to break down and change viscosity. When that happens, the hydro no longer performs as it should and if there are no drain and fill plugs, then life is not good for the tractor owner. The oil is critical because that's what transmits engine hp from the hydro's pump to the hydro's drive motor, just as the driveshaft in a car transmits engine HP from the transmission to the rear end and ultimately the rear tires. For the most part, these lawn tractors are pretty good machines providing the owners take proper care of them and use them as a lawn tractor was designed to be used. If I owned one, then it would have an hour meter on it for sure. After every two years of use, I would remove the trans-axle from the tractor, hang it upside down and let all the oil drain out of it for a couple of days. Then I would refill it with the correct oil and put it back into the tractor for another two years. When you do that, you are not only replacing the partially worn out oil but you are also removing contaminants that are in suspension in that oil due to the detergents the oil manufacturers add. High-end hydro's have oil filters to look after that problem. Low-end one's don't. No matter which brand of LT you choose, all you are truly buying is the name because 90 percent of the tractor's components are made by companies other than the one whose label adorns the hood. You are relying on them to select decent engines, trans-axles, tires, rims, electrical components, bearings, rod ends, springs, nuts, bolts, washers, drive belts and so on for your tractor. They just stamp out the chassis and some other metal bits and pieces before assembling everything. Find a dealer in your area that has an impeccable word-of-mouth reputation and buy your tractor from him. Get to know him because box store employees come and go and box stores do not perform warranty work on what they sell. They rely on the very dealer you should be doing business with so just cut out the middleman. Go and sit on all the tractor brands and if possible, test drive them if they have a used unit around or a demonstrator. Searching the internet is helpful but we all know that happy owners don't post on the internet but disgruntled ones do because they want to get even. Take your time, do your homework and then decide which brand you like, which deck width best suits your property and which dealer you feel really good about. It's your money and it's not chump change. You and that tractor will hopefully be married for at least ten years so this should be more than just an over-night fling. Think with the big head, not the small one. LOL