Hello there! I recently bought a 2013 Hyundai HL757-9 wheel loader that was traded in to a dealer of new and used equipment. I bought the machine being told that “It needs a transmission“ but they didn’t know why. I buy older stuff that needs repairs and fix it myself, that’s the only way I can afford to buy anything for my farm. The machine is in really good condition, well maintained, only 5200 hours, and spent its life at a mulch plant. No digging dirt or gravel or hard pushing. It has a ZF transmission 4 WG 190. I had to add fluid to the trans before I cranked it. When I fired the machine up for the first time, oil poured out of the drain/inspection hole on the converter housing (see attached photo, red arrow). Oil will flow out this hole under the converter as fast as I can add new oil in the fill neck, so no chance of checking gears. Could this be just a converter seal that needs replacing? Something much worse? Catastrophic internal failure? Anyone with knowledge of these transmissions that can help me with a little guidance here before I start tearing things apart will be greatly appreciated!!! Thanks, WW
Welcome to heavy equipment forums. To start with before taking anything apart that machine needs an all day bath with degreaser and steam cleaner. It will probably take a while but needs to be done perfectly. That means pans off and covers off. You just need to get one piece of dirt in the wrong place and it will be very expensive to find and repair. Need to get transmission filters off and cut open to find out what is in the pleats. Is there a suction screen plugged. Operators manuals will often tell where all the filters are. No need to rebulid what isn't bad. That being said , would be a good idea to get some manuals on this unit as you will need some technical info. Parts manual is also esssential for figuring things out. Probably good to do some pressure testing before ripping anything apart. Once apart, too late to pressure test. Could have some pump failed. Need to start out clean and end clean. Simon C
Well, it doesn’t look good. I cut the filter open and it had a lot of shiny glitter and friction material in it.☹️ I can’t do any pressure tests as it pumps the oil out of the converter housing as fast as I can put it in. Does anyone know where the best source is for parts and rebuild kit for the ZF transmission? Is there a trustworthy site online to download a parts catalog? Thanks, WW
Looks like a fair amount of shiny glitter. Any big chunks of brass or steel. Maybe filter was never done for long time. Any idea how old the oil was? Everything will have to be gone through to get any fillings out of system. No idea where you can look for parts. You will need some manuals. Simon C
There were no big chunks in the filter or in the bottom of the trans. I drained what little oil that was in it out. The filter had a date of 8-2022 wrote on it with someone’s initials, ZF brand filter. Looks like by service dates and hours that they stopped running it later in 2023, maybe 400-500 hours on transmission service. The machine is great shape, well taken care of, just a bad transmission. Hopefully there won’t be any major component damage, just replace normal wear parts and a very thorough cleaning. I’ve used a shop about an hour away that can rebuild the converter. Thanks, WW
Need to probably take apart and clean control valve to rule out junk in spools. Easier to do everything while out. Hope it all works out. Keep us posted once finished. Simon C
Hi did you figure out what was wrong with your transmission?