Grand L4740 hydraulic fluid leak. Ideas?

[lynrob]

Same thing happened to my L5740 at 150 hours and it was replaced under warranty. The WSM calls for removing the cab, but the mechanics were able to replace it without doing that.

Thanks TripleR! Unfortunately, my warranty coverage ended several years ago. Luckily, I have no cab so the split might be at least a little easier.

 

[varmint]

Now that you've got lots of concerned for you, please post as you go about dealing with this. Remember, takes lots of photos: maybe it will be very helpful to the next guy who has this problem! Good Luck!

 

[TripleR]

Thanks TripleR! Unfortunately, my warranty coverage ended several years ago. Luckily, I have no cab so the split might be at least a little easier.

Good luck, if mine goes out after warranty my brother will fix it as he's split tractors before and just "retired"(between us we have about eleven tractors). :laughing: I would hate to think how much a dealer would cost.

 

[RedNeckGeek]

I did a little digging through my Facebook posts and found photos and notes covering my tractor splitting adventure. I'm cutting/pasting below.


Tractor Cracking
Finally got the superstructure off the Kubota today, so it's time to split the clutch housing from the engine and find out what's leaking. Hopefully it's the three dollar seal I have on hand and no new parts will be needed.


Inside Out
The tractor came apart yesterday with surprisingly little fuss and just a little persuasion from hydraulic spreader tool. The front end rolled nicely on the jack, and moving it a few feet forward gave great access to the clutch and transmission. Only problem is I missed a seal when going over the diagrams, and now am waiting on a special order. The good news is that the clutch friction disc and throwout bearing look new, no surprise really since the tractor uses a hydrostatic transmission that does most of what a clutch would do in a "normal" tractor.


Tractor Trials
The new seal for the clutch housing came in Friday so Saturday I dove in to start on installing it. Quickly found that the old one wouldn't come out until the shaft it rode on was removed, and the manual said the shaft came out the back. But the back was attached to the transmission housing, so that meant separating the clutch housing from the transmission. What it didn't mention was that a hydraulic system feed pipe in the side of the transmission engaged a port in a pump inside the clutch housing (see orange arrow in photo), effectively locking the two together. Unfortunately, the porta-power unit did a very nice job of separating the two anyway, bending the feed pipe in the process. So the new seal is in place, and the clutch housing is back on the transmission, but reassembly is stalled waiting on a new feed pipe. Two steps forward, one step back. Gotta be more careful reaching for big hammers!


At Last
This is the leaking seal. It prevents transmission oil from migrating up a splined shaft that drives the forward propeller shaft to the front wheel drive. Oil that leaked past this seal flowed to the bottom of the transmission housing and out the drain hole that Kubota put there to let out any water trapped during creek crossings and such.


Flying the Floor
Got the floor installed on the tractor today with a little help from Mr. ComeAlong and his RatchetStrap buddies. I hate lifting stuff with a come-along, but it weighed less than a hundred pounds and there was no helper handy. Also got the hydraulic lines re-plumbed, and about half the wiring harness reconnected. Probably a couple more days 'till the thing makes brummm brummm noises, as I'm fixing previous owner secret broken stuff as I find it.

We got some good showers this afternoon; nice pitter-patter noises from the back porch roof. Very comfortable working in the garage. Can't believe how warm it is for December!

Hope this helps, and good luck resolving your issue!

 

[lynrob]

Wow! Thanks, Scot. A picture really is worth a thousand words! Your description has given me a much better idea of what I am up against. I truly appreciate all the info and the pictures.

 

[lynrob]

Got a chance to talk to the dealer today. After I presented the symptoms, he correctly (IMHO) guessed the problem is a 4WD drive shaft seal issue. He also said the cost of fixing it is almost all labor, 12 hours at $90/hour, minimum, plus a little for parts. He said that as long as I make sure to keep the oil levels up it is unlikely to cause any other issues if I keep using the tractor as is. I would love to attempt the fix myself but I am way too busy currently. So my questions are:
1. If it is the 4WD shaft seal, is is likely to fail catastrophically? That is, is it likely to suddenly let all of the oil out at once or is it more likely to continue as it is, leaking just a little at a time?
2. Would you have it fixed or let it leak? I generally don't like anything leaking, but $1200 is a lot to pay for what might be essentially cosmetics.
3. Does 12 hours at $90/hour seem like a reasonable rate for this repair or should I shop around? The next closest Kubota dealer is about 45 minutes away.

 

[RedNeckGeek]

1. If it is the 4WD shaft seal, is is likely to fail catastrophically? That is, is it likely to suddenly let all of the oil out at once or is it more likely to continue as it is, leaking just a little at a time?
2. Would you have it fixed or let it leak? I generally don't like anything leaking, but $1200 is a lot to pay for what might be essentially cosmetics.
3. Does 12 hours at $90/hour seem like a reasonable rate for this repair or should I shop around? The next closest Kubota dealer is about 45 minutes away.

1. The seal in my 3240 was leaking when I bought it, and over the course of another 40 hours of use it slowly got worse. Eventually it was losing about a quart every couple of hours, and that's when I decided to fix it, but I didn't feel like I was in any hurry. It was mostly a cosmetic issue, but the hydraulic fluid isn't cheap either, and I couldn't park the tractor on concrete without leaving behind a mess. I also didn't want the thing to get a lot worse in the middle of a job that I couldn't afford to stop, so over the Christmas holiday I started in on the repair and had it done early in the new year. Not much fun working in a cold garage, but cold was still 40F and not really that bad.

2. As mentioned in my previous post, I decided to fix it myself. I'm retired, and these days I have more time than money. The dealership was very nice about giving access to their mechanic, and in helping get the parts ordered, so we both benefited. Faced with the same situation, I wouldn't hesitate to do it again the same way.

3. That's a better estimate than I got. It probably took me double the amount of hours, but I'd never done that job before, and I spent a lot of time cleaning parts prior to reassembly and fixing other problems I discovered along the way. I also made some mistakes that cost me delays caused by having to order parts I damaged during disassembly. Even with that, though, I was able to do the job for about 1/10 the estimated cost. That in itself was worth it to me, and now I feel like I know a lot more about the machine, and have more confidence in my ability to fix it should the occasion arise again (and as under engineered as these things are, I'm sure I will).

 

[KenB2920]

I just wanted to add my two cents. My L3540 had the same issue. I will keep this short and make another post regarding all the issues. It was covered under warranty and fixed in about 3 weeks or so at the dealer. The dealer informed me that Kubota has put out an "UPGRADE" (in my opinion that is somehow getting around the work "recall"). Essentially the new seal has three ribs instead of two.

I will post a photo and when I have time, I will make a thread and post numerous photos









THis machine had 150 hours at the time of the issues. Since then, I blew the yellow hydraulic hose.

The first issue I had was reinstalling my loader. They had to pick up the tractor and fix it. 3 loader issues and I am now crossing 200 hours. My B2920 also had a loader issue. Valve issue.

Needless to say I keeping the tractor until warranty is up. I just found out the loader only has a one yer warranty ....

If I can get my hands on a L5740 for a good deal, I'll trade up. If not, most likely I won't be getting another Kubota.

 

[David_Kb7uns]

Got a chance to talk to the dealer today. After I presented the symptoms, he correctly (IMHO) guessed the problem is a 4WD drive shaft seal issue. He also said the cost of fixing it is almost all labor, 12 hours at $90/hour, minimum, plus a little for parts. He said that as long as I make sure to keep the oil levels up it is unlikely to cause any other issues if I keep using the tractor as is. I would love to attempt the fix myself but I am way too busy currently. So my questions are:
1. If it is the 4WD shaft seal, is is likely to fail catastrophically? That is, is it likely to suddenly let all of the oil out at once or is it more likely to continue as it is, leaking just a little at a time?
2. Would you have it fixed or let it leak? I generally don't like anything leaking, but $1200 is a lot to pay for what might be essentially cosmetics.
3. Does 12 hours at $90/hour seem like a reasonable rate for this repair or should I shop around? The next closest Kubota dealer is about 45 minutes away.

This is peak time for them, if it is a slow dripper, then I would wait until this winter the dealer has been known to do services specials in the off time. Could also talk to Mid Valley or Rickreal and see what they charge.

While not as bad as your problem where you have to split the tractor, I broke the right brake case where the right lift arm attaches and did it myself involved taking fender, axle trumpet and Rops off. LB even had a fire damaged L series that they pulled the part off of.


David Kb7uns

 

[westflgator]

Thanks for taking the time to share this info with the rest of us, it is very helpful. I do have a few questions before I move forward with this repair. I have a leak coming out about half way down the propeller shaft. There are some seals in the shaft itself along with the seals that you replaced. How can I tell for sure which seals are causing the leak? Is it possible the seals in the saft itself are the only ones that need replacing? I just wanted to double check before tearing into it. I have attached a pic of where it is leaking. It's not running down the outside of the shaft and dripping, it's actually coming from the inside of the shaft and dripping out where its coupled together. I also wanted to know if there are any specialty tools needed to replace the seals shown in your posts in this thread? Thanks again for all the help.