Oil in clutch housing

[lincolns]

New Kubota owner who is using mechanical ability and the internet as a stand in for mechanic experience (which I have none).

I bought a grey market L1801DT with 850hrs. Seller told me the clutch needed replacement. I could operate it fine, but the clutch tended to jump into motion no matter how slow you came off it. So his explanation made sense.

I bought the tractor in the late fall, when I got it home, I expected it to leak oil as there was so much oil on everything. I degreased the engine and washed it down to see if I could get an idea where it was coming from. I did not run it that much before storing for the winter. I expected it to leak and put cardboard down, but it didn't at all.

In the spring I got it running and ran it around a bit and then decided to do the recommended "new to me change" of all the fluids and filters. Since I was doing the full fluid and filter replacement, I decided to split it and do the clutch while the transmission was empty of oil.

Drained all the fluids, and split the tractor. Oil started coming out of the bell housing as the halves came apart. With better access to all the engine parts I started to notice that there was a lot of gunked-up oil on the engine. lots sludge on the shaft sleeve that runs up to the front wheels and on the starter motor.

With the tractor apart I could see into that oil was sprayed around the bell housing (see picture).

I think I have a leak in the from transmission, (possibly engine?) into bell housing. I have done searches through OTT forums and this sounds reasonable based on my observations.

Since I have the tractor spilt I cant' really do some of the diagnosis suggested in other posts. I can't spray in brake cleaner and leave the drain nut out and see what I get after running the tractor. The oils are drained so is leak is not going to be evident. Based on the excessive sludge everywhere (from longer term accumulation?) I dont' think this was a oil leak produced by steep incline/decline or over fill of transmission -- it has been ongoing.

Question is... what do I do next?

Can I provide more information that can help the actual mechanics on this forum with enough to diagnose the source of my problem?

Since the tractor is split, should I just replace seals and o-rings? If so which ones?

Is it possible that my clutch is fine and it was the oil that was making it jump? If this is a possibility, is there any way to determine if I should continue using my current clutch? Should I switch it out since I have it sitting in a box and my tractor is in two pieces.

Lastly, I will throw in one more picture of the exhaust port after removing the manifold which needed a new gasket. Lots of black build up on both ports. I have no idea if this is normal or otherwise.

Thanks for any advice you can give.

 

[Stumpy]

The hard part is done, it's already apart, so it makes no sense to put it back together and risk not having solved the problem. I'd replace your clutch, pressure plate, throw out bearing, and rear main seal. The clutch disc has been soaked in oil and is trash, the pressure plate (mostly the springs) and throw out bearing are routine maintenance when doing a clutch job. Due to the color of that oil it's good money that's from the engine and the only place that could have come from is the rear main seal. I show how I did mine on my L175 which is very similar here. Degrease everything like you intend to eat off of it and just before you install the pressure plate hose the flywheel and pressure plate with brake cleaner.

Examine that seal closely to see if you can tell what caused the failure. Hummm... In the rear cylinder's exhaust runner are the deposits dry or are they wet with oil? It's hard to tell but if it's wet you've got a problem with the valve guides like I had. Read my thread and you'll see the mess I found inside my motor.

 

[Kytim]

since your in there, do it! You've done about all the hard stuff. Stumpy has a great pictorial posted, follow his advice. now is the time to R&R everything that is even remotely questionable. you dont really want to do it twice, do you?

good luck, keep us posted.

 

[lincolns]

I'd replace your clutch, pressure plate, throw out bearing, and rear main seal... Examine that seal closely to see if you can tell what caused the failure.

I will get the clutch, pressure plate, and fly wheel(?) off and have a look at the rear seal.
- Do I just need: part 17 in the attached parts schematic?
- Do I just remove washer covers (14,15,15,16) and seat new seal?
- Is there other parts I should replace when I do this seal?
- Is there a chance that the oil is coming from the transmission seal?
- Is there anything I can do to diagnosis this possibility?
- Is it a major job to do both seals since they are accessible now?

From memory, when I drained the transmission fluid, it was pretty black looking too. Having a look at the pressure plate, it is less messy than the back of the housing, but I did not get the plate and clutch off to look at the front end of the housing. I will do this next weekend hopefully.

Pointing to the oil coming from the rear seal is all that oil gunk on the starter assembly place to exit the bell housing?!?. Any suggestions on things I should check before I come back to the list with what I find... just let me know.

Hummm... In the rear cylinder's exhaust runner are the deposits dry or are they wet with oil?

The deposites are dry and crusty. When I got the tractor, the exhaust had the pipe above the muffler replaced with just a straight piece (no bend at the top). When I took manifold off, there were 4-5 cherry pits sitting there.
- Could the objects bouncing around in there have encouraged build up?
- Should attempt to clean this (if so how?)... or just leave it?

To answer your question, the deposites were dry. I have added a close up photo.

I added a flapper to the top of the exhaust (photo of it hanging after painting) to keep rain and objects out of the pipe.

Thanks for the help

 

[Stumpy]

That exhaust runner just looks strange to me, kinda earthy. Carbon deposits in the exhaust manifolds should be a thin layer of very fine dry baked on carbon powder. Can you see any oil on the valve stem? I don't see cherry pits causing any symptoms in there, chances are they wouldn't make it past the valve to the combustion chamber.

Once you get the pressure plate and clutch out of the way there should be 6 bolts with three of those lock tabs. Then you've got four more on the bolts that hold the seal plate to the rear main bearing (there aren't any on the bolts that go into the block). All should be replaced though Messicks couldn't get one or two for mine so I just made them all out of I think 14 gauge sheet metal, I specify the gauge in my thread somewhere. Once the seal plate is pried out you've got two gaskets to replace (7 & 9 on the diagram) in addition to the seal. You really should use a press to remove and install the seal in the housing but it can be done with a hammer and drift (just not well). Once everything is square assembly is straight forward though the clutch takes a little fanangling to get it centered without a centering tool. I go over that in my thread. I used red loctite on the bolts that didn't have lock tabs just for peace of mind, they're gonna be a pain to remove later though.

It's possible it came from the transmission but tranny oil doesn't turn black like that. What I've heard can happen is if you're going down a steep slope and the tranny is overfull oil can spill over the top of the transmission wall into the bell housing but it still shouldn't have turned be black. You might want the change the tranny seal but I'm not exact sure what's involved in that. I believe you need to take the transmission off of the rear axle and remove the main shaft. I really don't have any ideas for diagnosing a leak in the transmission shaft but if you take the pressure plate off and secure everything well you could probably start the engine and see if you get oil leaking out of the rear main. Be careful doing that if you decide to try it.

I'm out of time for now, I'll look at this again later and see if anything else comes to mind.

 

[lincolns]

I am going to order the 2 gaskets, rear seal, 4 washer tabs for the seal and 3 washer tabs for the fly wheel. Then I guess I will dive in once they arrive.

As a test, I am going to take out the drain plugs for both the engine and transmission oil. Both reservoirs have already been drained, but I imagine that over the last couple of weeks the more fluid will settled to the bottom and I can get a sample of each.

I will compare this to to what is in the bell housing and see if I can say which direction the oil is likely to be coming from. Hopefully the engine.

I will report and take photos as I go. I will definitely be going through Stumpy's restore thread more than once while I wait for the parts.

If anyone has experience replacing the transmission seal to the bell housing please comment on what is involved.

Thanks for your input!

 

[lincolns]

Carbon deposits inside the exhaust manifold look pretty normal to me; I've seen worse for sure!

The gasket between the muffler elbow and the manifold was completely missing, and may have been like that for some time. Could the missing gasket have promoted the deposit?

Is there any point (or method) of cleaning out the exhaust, or should I just let sleeping dogs lie?

 

[Breeze]

I've been following your issue.

Rear seal (crankshaft seal) goes bad for two reasons?

1. Hours/Cooked lube
2. Crankshaft movement, main bearing slop

One diagnostic tool I rarely if ever see mentioned is oil analysis. Lubrication analysis and vibration analysis are the two most common tools employed on industrial rotating equipment. The best results are obtained if a baseline is recorded, before problems start, but with an onset of a problem such as rear seal failure, analysis of what's in the lube oil can be valuable.

http://www.blackstone-labs.com/what-is-oil-analysis.php

This is just one of many sites that can analyze the lube, I have no dog in the hunt.

Cheers.

 

[drewscruis]

I've also seen rear main seals go from the engine just sitting and moistre gets between the seal and crank. Rust devlops and then when you start the engine it tears up the seal.

 

[Sylvester]

I think your question has been answered, but oil has a smell, have a little sniff at your engine dipstick, then the gearbox dipstick there will be a difference. To be fair, gearbox oil would still be reasonably clear if it was leaking, engine oil normally black with a characteristic smell.