Hi everyone, I'm new here and I'm in the process of fixing a leak on my excavator. It's a 1984 Kubota KH28L. It was leaking gear oil from the swing gear case rather quickly. I looked in my parts book and saw that there is a seal where the pinion gear shaft comes out the bottom of the gear case. So I figured that after almost 30 years the seal probably just went bad. So my brother and I spent most of the day yesterday tearing the machine apart to get to it. We finally got the gear case out, and it appears that the lower bearing on the shaft is bad. I haven't gotten the large gear and bearings off the shaft yet (had to borrow bigger puller than we have), but the shaft seems like it has far too much play in it (it's a roller bearing, so there shouldn't be any play along the axis of the shaft). I'm guessing that with a bad bearing it won't hold oil even with a good seal. Does that sound right? Anyone have any experience with these older machines? Hopefully I can get it pulled apart the rest of the way tomorrow after work. I looked up a new bearing from a few dealers online and they go for almost $200 ea! But I guess that's better than putting a gallon of gear oil in it every week! Thanks!
If lower bearing goes down, you won't have a prayer of keeping oil in the gearbox. It's a good thing you're fixing it before carnage happens. Of course, you likely have a bunch of gear oil in the slew ring base now as well.
Thanks for the response. I did get a bigger puller and got the upper bearing off (#16 in diagram). Then the upper collar, gear (#9), and lower collar came right off. However, now I'm having trouble getting the pinion gear shaft (#10) out of the lower bearing (#17). I tried using a puller attached to the case to push it through, but it's in there pretty tight and nothing I rigged up would hold it steady enough to get enough pressure on it. I'm afraid of putting too much pressure on it, but I've never done something this big before, so I don't know how much is ok. I was thinking of bringing it to work tomorrow and using the press with a 20 ton hydraulic jack to see if that will get it out. Any better ideas? Luckily, the belly pan on this thing is quite loose, so all the oil drains right out onto the ground Thanks for any help!
Well, I finally got it all apart, and the lower bearing isn't bad after all. I thought that it was a flat roller bearing, but it's really a twin taper roller bearing, so it can pivot. The spring in the seal was broken, so I think that's why it was leaking. So I ordered a new seal for $30 instead of a new bearing for $200! I hope this does the trick.
Hi Mater, I read your post with interest and realise that it has been a while ago now, but I am interested in how you went about getting to the seals and bearings - i.e. did you have to remove the entire top half of the excavator? or is the bits detailed in the exploded diagram removable from the underside? If you don't mind giving me a few clues as I will one day want to investigate why my old Kubota has a roughness to the turret rotation, and to just check bearings and any adjustments (there is some play in this section). Cheers Peter
Hi Peter, It has been a while since I did that, and it's still holding oil just fine. In order to get to the swing gear case (the left part of the diagram above), I had to remove the fuel tank and hydraulic oil tank and most of the hydraulic lines going to the boom, and also removed the bolts for the cab and moved it over a few inches to gain enough space to remove the gear case. It is not accessible from the bottom. However, if you are trying to get at the main turret gears (right hand side of the diagram), they are somewhat accessible from the bottom, but I didn't do anything with them. Good luck! Glen
Glen, I had the same problem a few years ago and had to have a gear made...$1000 just for the gear. Does your KH28 have the roll cage and extendahoe? I have not seen many of these. John
Hi John, Wow, that's expensive. I'm glad I didn't have to spend that much! Mine has a cab, but no extendahoe. It does have a blade and a thumb. The most recent addition to it was a Wain Roy coupler and 30" digging bucket. I can move some material now! Glen
parts and issues Hi guys, I'm upgrading from a backhoe and found one of these for sale near me with an extend a hoe and rubber tracks, its at about 4500 hrs, any advice on finding parts and notable reliability issues for these at this many hours? Thanks for the time and input
Hi, My experience with the machine is that at this age, a lot of the pins and bushings will be loose. I haven't had any issues finding parts, just finding the money for them! It has been a very reliable machine - 30 year old technology is pretty bulletproof. that's my 2 cents Glen
Thanks Glen, I had a guy look it over for me today. He confirmed the bucket is real sloppy but didn't have anything to say about any other bushings or pins on the boom or stick. Are there any in particular you would worry about? The guys at Coleman online told me I could get pins and bushings for the bucket assembly but from the pics its so far gone by the holes are all ovaled out so Im not sure how big of a project it is to tighten up. Also any Idea how to date these machines by the serial number? Thanks, Greg
got the date of the machine from the dealer, it is a 1985. The price they gave for parts to do three bucket pins and bushings with links was about $2800 in parts only. I am having second thoughts, I cant afford to take on a project right now...
Hi Greg, My bucket bushings had ovaled out the end of the stick as well, so I used a wire feed welder to build it back up and then used a metal cutting hole saw to round it back out so the new bushings would fit. The bushings were about $150 and I used a piece of 4140 hardened rod (about $70) from McMaster Carr for the pin. Now that's nice and tight, but some of the others need to be done as well. Probably the next sloppiest one on my machine is the stick to boom joint. I haven't done the other two bucket pins yet, but they do need it. Mine is an 84 and it has the date stamped near the serial #. How much do they want for the machine itself? Glen
thanks for the reply, I too was thinking that I could weld and repair the bucket slop in a similar way. thanks for the details. They want $15K, despite the age it is the best deal for the size that I can find. I m planning to take it this weekend.
That seems like a fair price from what you've described of it. Is the rubber in good shape? Once you pick it up, you'll have to post some pics! Good luck with the new toy
Hi Greg, Any update on the machine? Just curious how you like it. Glen
track rollers So I bought it and put it right to work. On the way up the hill it dug in two drainage culverts and cleared years of sediment from a roadside bed. Up top of the hill we did some further inspection. Basically, the undercarriage on the right side has 4 decent rollers and 1 pretty worn out one. The left side however has 5 pretty worn out rollers. My first though was to swap 2 from the middle on the right side for the ones positioned in the front and rear on the left side. Do you guys think this will work to help even out the wear on the tracks or do I need to just bite the bullet and source replacement rollers now? Any advice on where to find some rollers for the 28L? thanks , Greg
So far I really like it, I will have to get some pics from my site and show you some work we have done. It is strong and moves a lot of material. We went through the entire thign and got almost all the grease fittings taking grease again, that was a mess but very exciting to see most of them take grease I keep generating a new questions so perhaps I can learn from some of your experience with keeping this thing running...especially considering I am new to the excavator and have no manual or service guides to go on. what do you recommend for oil in the final drives and how often do you recommend changing it out? I have seen a number of different pieces of information out there. thanks, Greg
Looks like it's in pretty good shape! By the looks, it's been repainted too. Definitely cleaner than mine... I'm not surprised that it's strong - these Kubota's are too strong for their own good! It's real good that you got the grease fittings open. Keeping a machine greased is one of the most important things you can do for it. For the rollers, it may help somewhat to swap the good ones to the ends. When you say pretty worn out, does that mean there's play between the roller itself and the roller "axle"? Also, are you having trouble with the tracks falling off or anything? Where in the US are you? I bought my track parts from a small equipment place in NH, and they got them from a company in Canada - I think it was called Toronto Track Parts or something. The rollers were about $150 each. For the final drives, I think I just used 75W90. Making sure there's clean oil in them is more important than weight. Unless you do lots of ground traveling, it shouldn't be an issue. I would say it wouldn't hurt to change it every 500 hours or so. I do have a book somewhere... I'll see if I can find a maintenance schedule in it. I'm happy to help with anything I can! It's exciting to know that there's someone else in the world that still uses one of these things! Let me know if you need parts diagrams or anything. I have both a parts book and owners manual so I can scan pages if needed. Good luck with it! p.s. is that a plate welded on to the boom near the main lift cylinders? If so it must be a weak point because mine has plates welded on either side in the same place.
It is a welded on plate, I didn't see any signs of a break but it caught my eye yesterday as it didn't really look factory. I am in western Maine with my camp. For the rollers, when I say warm out I mean lots of play, it looks like some of them are in three parts and flopping and banging around in there, lots of play between the roller and axle and the other two are seized and flattened on the lower sides with tracks just sliding by. the other side however seems to be rolling well for now. I haven't thrown a track yet but have been jump turning it almost exclusively.
Hello all, I am new to mini excavators and had a question. Does anyone know if the Kubota KH28L is the same as a KH170L? I am considering buying a KH170L from my neighbor but apparently that is considered to be an overseas machine. The ROPS over the cab has a tag on it and shows it is from a KH28L and from the pictures I have seen the KH170L and KH28L are twins. If anyone knows if these machines are similar as far as parts interchange it would be extremely helpful! Chris
Hello, Would you have a picture/diagram of your KH28L final drive assy? I am looking at purchasing a KH170L which is apparently an overseas machine, I am trying to find out if the 2 machines are the same? Any help would be much appreciated. Thanks Chris in NH
They are the same
Chris, I do not know if they are the same but would love to find out. I send you a email, if you respond i can send you the final drive assy diagrams as an attachment. How many hours on the machine and how much does he want for it? as you can see from the posts I just paid 15K for an old KH28L a month or two ago. -Greg
Final Drive, Are they the same the machine or just the final drives are the same? I need bottom rollers for my KH28L and found a salvage yard with a 170L but no one can tell me if the rollers are the same. Thanks, -Greg
http://www.messicks.com/ I always deal with Messick's. The final drives are the same. Kubota's website doesn't work very well, so I can't confirm the roller part number. I'd give Messick's a call and talk to the parts department.
Hello Greg There are approx. 3200 hours on the KH170L, he want $9500 but I am skeptical if parts will be an issue. Started and sounds excellent but hydraulic tank was very low so was not able to test it. He had put new sprockets on it years ago and has very good used chain assy for it but never actually used the machine. I is a 1995 and in excellent visual condition but like I said, parts availability is a concern, especially since it has sat for so long, The final drive is odd looking to me, like a gear reduction box, and I can imagine the parts inside there would be impossible to find if needed. That is why I am wondering if the KH28 is the American version and perhaps could find a dealership more willing to search for parts? Chris
Hi Guys I am new here so not sure how this works but any help would be great, I am in Ireland and i have a KH 170L and it digs great with plenty of power but when it tracks there is no power it will not push any soil with the blade and is very slow going up a hill, any help would be great.
I'm not familiar with the KH170, but if it's the same as the 28, check to make sure its not in high gear.
Kh 28 Hi thanks for the reply i have just found out that is actually a KH28 was the wrong decals on the machine but how do i check to see if that is the problem. Thanks
If it's the same as mine there should be a pedal on the floor by your right foot that engages the high speed travel. Make sure that's not stuck, and or bypass the switch temporarily to see if it will drive at low speed. Another option is to turn the key off, but leave the engine running and then try the track drive. The high speed mode is electric, so if the key is off it shouldn't function.
Hi thanks for the reply and sorry for the delay as i was away, when i push that pedal there is no difference and when i turn the key of it still moves at what seems the same speed, now i was using the digger today and it seemed to push the soil a bit better as i had broken a pipe and filled it with new oil but when the machine was warm it would go straight no problem but it would not turn at all, it is a great wee digger if i could get it going 100% it would be a cracking digger, do you know anywhere you can get spares for these old machines also. Thanks for all your help its greatly appreciated..
It sounds to me like the circuit for the high speed mode isn't working properly. I would recommend checking all the wiring and switches on that circuit and make sure that is working properly. I believe there is a switch on each track lever and one on the pedal for high/low speed.
Glen, It's been a few years since I've read this forum. Where did you find the Wain Roy coupler? My swing gear is leaking again. I need to to remove the gear case and replace the seal. John
Hi John, it's been several years but if I recall correctly it was a guy in north eastern Mass that sold used machine attachments. He had a huge yard full of all different types and sizes. I don't recall his name. I found him on Craigslist so I'm sure the posting is long gone.
Hi everyone, bit of revival this but I’ve recently bought a Kubota kh28L in the Uk, can anyone tell me where to find the drain plug for a swivel gear case? I can find the dipstick. Just on the process of buying a manual for it to help me along as it needs a few bits doing Thanks
Hi George, it's been quite a while since I've sold the Kubota so I don't recall exactly where the drain plug was located. But I think it has to be accessed from the bottom of the undercarriage, after removing the belly pan. Maybe someone who still owns one of these older Kubotas will chime in.
I just happen to have the case out of my KH28 so here is what you're looking for. It takes a 8mm allen key and is accessible from the small hole, belly pan doesn't need removed
That’s great I’m looking in the wrong place, thanks for the help
Hi there, got the slew gear oil changed I’m after some more help with the tracks, does anyone know the pitch and how many links there should be?? Also I have one side that’s really slow any ideas where to start looking? Thanks
Not a lot of info, but check the thread linked above.