One of the final drives is leaking on my 8 ton kubota excavator. I have never had a final drive leak before. I was wondering how hard/big of a job it is to change the seal and what's all involved . I am hoping to fix it myself. Thanks.
It is gear oil that is leaking. Couldn't physically see oil. I could smell the gear oil. So I checked both sides and one final was down about half a litter of oil.
You are lucky to have found it now. A photo of the outside plate of the final might tell us who built it originally. A regular planetary drive isn't too much of a job. Problem is now days they use a small drive and it might be a big pain. Most of those units now days get thrown in the scrap pile and a new drive purchased.
Here is a picture.
It's a Nabtesco drive. Easiest way is to pull the whole lot out and disassembe. There is a duocone seal that will be leaking.Also check the bearing, it could have worn causing the seal to leak.These drives can be a bugger to get into. In the gap around the plate were the bungs are there is a spring steel wire that locks it together and you need to find the ends to remove it.It will test you. Parts are availiabe but if you have problems getting them Pm me.A business 2hrs from me has parts in the shelf.
Any luck with this?
I'm going to keep an eye on it for a while and run it. Kubota wants a $1000 just for the seal. Hoping the warmer weather will stop the leak.
I just had a yarn with Murray at Travel Motors Direct . Depending model $250 AUD top price. If you email him he will put you in contact with a company in your area who can help. Email; [email protected] Just remember if oil can get out dirt can get in PS If you remove the cover on the motor side there should be a tag on the motor with serial and model numbers. Hope this helps
How did this end up?
I have the same problem with my E70B Cat excavator, slow seeping out the quad rings on both planetaries. Travel was weak so I went ahead and replaced the rotary swivel seals, which was an easy and cheap job on my machine. Travel has a little more power now. I haven't run it enough to know if that fixed it. My theory is that bad rotary seals will have the same effect as a restricted case drain, putting more pressure on the duo cone seals. Correct me if my assumptions are wrong.
Aren't the face seals purely on the planetary gear side of the drive?
I'm no expert on this. I suppose by face seal you are referring to the large diameter quad O ring. My thinking is that the pump is leaking hydraulic out the shaft end and forcing it's way into the planetary reduction, pressurizing the cavity by adding hydraulic oil. I don't know if there is any other passage for the leaking hydraulic oil to get out.
Thanks, the definition I have is; Face Seal (feɪs siːl): a device used to distribute oil over a wide area, at the most inconvenient time, resulting in obscenely costly repairs and general misery to mankind.
I added the oil and it didn't end up leaking anymore.
Cool, thanks! That was lucky. I'm hoping for the same from mine, but don't think I will have the same luck. Good to know it sometimes does clear though.
It did happen in the winter so maybe the cold had something to do with it.
Most final drives I've rebuilt the steel face seal simply keeps the oil in the gearbox portion. If it fails, oil just leaks out onto the track. If the motor shaft seals go, it will fill the final drive up. It can blow the face seal out if it gets enough pressure inside the final drive. Most common failure cause of the face seals I've seen is a loose bearing. Sometimes in extreme cold if the operator drives off a trailer or a pile really fast with the final drives leading the shock of impact can sometimes crack the seal.
I hope you are doing well. I have the same issue but I can't find the "rubber" seal anywhere! Cat sold me one (part #: 096-2138) but it was far too "skinny" but had the correct circumference. My seal is like 4 times fatter than this Cat part. I have a 1994 Cat E70B excavator. Who is the business that has these fatter seals? Thanks in advance. Andy
Looking for a fatty? Head on over to the new member forum and introduce yourself. Welcome to the HEF, by the way. Looking for Caterpillar advice in a 12 year old Kubota thread isn’t going to work very well.
Thanks for the schematic. However, that part number is not accurate to my machine for some reason!? That o-ring is far too skinny. Mine is much fatter. Like 4 times thicker. This is the part Cat keeps selling me but it is not right for my machine. From the posts above there was another person with an E70B. Wondering if they also needed a fatty o-ring? A post above said that these drives are Nabtesco drives but that didn't help me source the o-ring either. Coaldust- thanks for the warm welcome. Didn't realize this was a Kubota post. I saw "leaking final drive" and another e70b post and figured it was the right place. It appears based on the pics above that my drive is the same (or nearly the same) as the Nabtesco drives.
Serial # would be a great start. Could be several different e70b models out there. Hopefully this isn't a Gray Market machine because that'll usually make things complicated.
1994 Cat E70B. Pin: 7YF07790. Serial : 00B40759. Engine: 4D32. It's Japanese made so my guess it's gray market.
Here's some numbers I got off the inside of the cover plate (the metal plate that is held in by the wire ring and has the fat rubber o-ring around the inside: 810B-1008-0001 and 3G-10.
You're going to need the Japanese Parts Manual for that Serial Number. There is no information in the Cat online system for the 7YF-prefix machines. Don't worry about the fact it is in Japanese, the illustrations and the Pat Numbers will be intellegible even if the descriptions are not. It can be downloaded form the Cat Publications web site, but unfortunately it's not free.
Here's the plate from the final drive itself. This didn't help me either unfortunately.
It wouldn't. Unfortunately there's nothing on there a Cat dealer could use to identify the internal parts.
Gotcha. So the part numbers out of the Japanese parts manual will yield results online but the parts will be foreign purchases I presume?
Not necessarily. The Japanese Parts Manual will produce "genuine Cat" Part Numbers that the dealership parts counter sales system will recognize. There's your first win right there. Where they have to be initially supplied from is neither here nor there as far as they (or you) are concerned, except for the fact that if they have to come a long way it will take more time. It could be that the particular Part Number you need is actually in stock somewhere in the US. The major challenge at this time is to actually identify what Part Number it is so that someone can start searching for the nearest one......... The Parts Manual can be downloaded in Adobe pdf format by clicking this LINK , put XJBP9938 in the box then click Search. The whole process normally takes about 5 minutes.
096-2138 cross section 0.14 I.D. 9.23 7I-2329 cross section 0.27 I.D. 8.97
Maybe confirm the location of your leak.? I was thinking it was #1 & 2 you were looking for, a Duo-cone leak in other words even though the face seal in this assembly is not exactly of that design.
So I purchased the Japanese parts manual. According to that manual the part number for the fat rubber o-ring is: B74600436 (page 533) or Z441102600 (page 538). Both schematics look the same to me but since I can't read Japanese I don't know what the difference between the 2 part numbers would be. Regardless, both those numbers are referring to the fat rubber o-ring that goes on /around the outer final drive plate. My leak is definitely coming out of the front plate where you fill and drain the gear oil from. When I took it apart the fat rubber o-ring is flattened in a couple places and I suspect that is where the oil is escaping by. Since the Cat 096-2138 o-ring was too skinny I put everything back together and sealed the outside with Suzuki gasket sealer. It's a "bandaid" and seems to be holding the oil in. The gears looked good inside so I think I caught the issue quick enough. I would like to fix this issue properly though. Thanks for all the help here!
There are apps that will translate Japanese to English on your phone using a photo of the page of the parts manual. That might help.
Thanks! I didn't know that! Off to the Google Play Store to see what I can find!
See this thread - HeavyEquipmentForums
If that wasn't the coolest thing! Screenshot the page and place inside Google Lens and Google Translate translated everything! Wow! Anyhow, it appears Z441102600 (page 538- bladed machines) is the fat rubber o-ring I need. Guess I'll give Cat a call tomorrow and see what they can find. My search online yielded no results. Heymccall's part number for the 7I-2329 yielded results and the specs on it seem like they are correct. Stock on that o-ring is good and cheap (<$17) so it might be worth a shot!? You guys ROCK so many many thanks for your time and patience with this! I got a laundry list of ailments with this machine so I will be researching/posting on this forum much more! Thanks again! Andy
Check your messages That tag is the most valuable info you have.
It happens that I just had the same problem and this is how I solved it. I removed the spring steel wire by drilling the gap at the ends of the wire withe a carbide burr. This made slipping a pick behind one end easier and I got that out. Then I pulled the plate off with a slide hammer I modified for the purpose. 3/8" pipe thread fit the drain holes perfectly on my machine. Cat gave the specs for the suggested "o"ring but I could have easily measured the diameter and thickness of the o ring with calipers. I ordered a new o ring from Hercules seals for about $6 and it fit perfectly. Hercules Seals has an online catalog with just about any seal you can think of. Just pick your size and order it. I cleaned and sanded the receiving ramp so as not to damage the o ring when installing the plate. I applied grease to all the mating surfaces and the o ring and it slid right in without damage. replaced the spring retaining wire and it was perfectly sealed. Hope that helps the next guy that runs into this. It was about as easy as it gets.