M35B Oil Leak

truewind · August 10, 2022, 09:52:54 AM

Here is my problem. I changed the oil and filter on my M35B. There was no problem with the motor leaking oil until I changed the oil and filter. Once the motor was started and when the engine warmed up a bit oil started leaking at the place where the engine block meets the gear case housing and it occurs right where a bolt that helps secure the gear case to the block, which happens to be right next to the oil filter. Let me stop every one of you who are going to say "it's the filter", or "did you apply oil to the filter gasket before screwing it on". The oil leak is where the gear case meets the engine block. You can see in the two attached photos with a red line showing exactly where the oil is leaking from. I tried tightening down all the gear case bolts and it didn't change the oil leak. I removed the gear case, replaced the gear case gasket and the four o-rings and after re-assembly. The oil leak cam back in the same place. I am going to remove the gear case again and perform a dye penetration test. Even though I hand tightened the oil filter, the fact that there was no oil leak until I changed the filter makes me believe the there is a fine hair line crack in the cast aluminum gear case at or near the oil filter. I am posting this in hopes some one has a true insight into an issue like this. Let me save those that wish to help by saying it is not the oil filter that is leaking. It is leaking at the point where the red lines are.

I have received a price for a new gear case from Westerbeke. I went into cardiac arrest. I know that my M35B model is a V1305-E Kubota block. When I called a big Kubota dealer and gave them my serial number of my engine, the Kubota web sight refused to let them get the correct Kubota part number. I suppose they have gone to bed with Westerbeke and locks out anybody but Westerbeke. Has anyone here replaced their gear housing on a M35B and got the part from a Kubota dealer. I feel like there has to be a way to get that part from Kubota without a bottle of oxygen and a EMS truck out front to revive me.

mark_53 · August 10, 2022, 10:55:29 AM

How about putting some liquid gasket on the leaky spot?

glennd3 · August 10, 2022, 11:06:39 AM

I am not familiar with your engine, however looking at the gear cover and the block I cannot exactly tell the route the oil takes through the block. I see the 2 oring seals that are for the oil journals. Also, the gasket seals around the block and cover where the filter empties into the engine. I might follow the oil flow. Maybe something in the filter or cover is restricting the flow cause abnormal oil pressure which is causing the leak. I know you said not to mention filter but if the oil is being pumped/forced into the wrong or somehow restricted filter maybe causing the leak. The filter is the only difference that was made. just a thought

waughoo · August 10, 2022, 11:56:03 AM

If you suspect a hairline crack, you might want to have it x-ray'd (magnaflux) at a machine shop to see if it can be spotted and they might be able to weld and regrind it. This was a common repair in the classic car world to save non-replaceable parts.

Ron Hill · August 10, 2022, 02:20:15 PM

Alex : Magnaflux is only good with a ferrous material!!

Continue the dye check for a hairline crack. What I'd try is a thin coating of #2 Permatex (non-hardening) on both sides of the gasket - applied to the metal castings surface & into the hole of the gearcase. Then put things back and see if that doesn't solve the leak!!

A thought. Ron

truewind · August 10, 2022, 02:30:03 PM

I did put a coat of Permatex #2 on the mating surfaces and a new gear case housing gasket when it was put back together. Same issue. I'll be back, after dropping my son off at Clemson this Friday (Free at Last

) at the boat with my dye penetrant next week.

If all that fails, Im really interested in trying to find a Kubota dealer that can tell me what Kubota part that is as apposed to selling my blood to pay Westerbeke's price.

Please keep the ideas coming.

Thank You
David

mark_53 · August 10, 2022, 04:32:47 PM

Maybe put the old oil filter back on.

rmjohns · August 10, 2022, 04:41:30 PM

It looks like from the picture of the block that there is corrosion right where the arrow is pointing. It looks like the paint has flaked off just above and below the bolt hole. How did that gasket surface look on the block when you took off the gasket? Did you scrape or sand it at all prior to the Permatex? How about the block right behind that area? Or maybe corrosion on the bolt? It looks like a hollow area behind the bolt so maybe oil is coming up the bolt threads? Though that wouldn't line up with where you see the oil. It's hard to tell from a picture, but if that area is corrosion then I'd focus on that a little.

Rob

rmjohns · August 10, 2022, 04:44:28 PM

Actually now that I look at the picture of the gear case cover, it looks like the bottom of the oil filter mount is corroded. Hard to tell from a picture, but it might be worth looking at closer.

Ron Hill · August 11, 2022, 02:02:48 PM

David : To get a Kubota part the best way is to find out the Tractor that uses that engine equivalent to a M35BC engine!!

I now have a M25XPB engine which is a 3 rather than a 4 cylinder engine. On the outside chance that that gear case might? be the same my "B" engine? It (M25XPB) is used in the Kubota F2400 and the F2560 'tractors". If you can talk to a Kubota mechanic I'm sure they could tell you!! Anyway might be worth a try!!

Also the most likely place for a crack is at that ear hole on the gearcase because that casting is aluminum alloy and MUST be properly torqued. I broke one of the ears for the alternator bracket (on my engine) because there was a slight!! space inbetween ears and when tightening - that aluminum casting ear does NOT bend!!!

A few thoughts

Stu Jackson · August 11, 2022, 04:57:52 PM

Quote from: truewind on August 10, 2022, 02:30:03 PM
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Im really interested in trying to find a Kubota dealer that can tell me what Kubota part that is as apposed to selling my blood to pay Westerbeke's price.

Please keep the ideas coming.

Thank You
David

David, you need the tractor #, not just your engine serial number; Ron's right. This site & forum have all sorts of repeated listing of what tractor each Universal engine was based on. Use "equivalent" or other search terms. I don't have that engine, my M25 is a B6200 Kubota tractor and I get my parts from my local Kubota guy down the lane. Try the wiki, too.

Ron Hill · August 13, 2022, 01:39:12 PM

David : There have been posts on this message board with the Kubota tractors that use each of our "Universal" engines - the M25 / M25XP and M35BC engines!!

The tractors I know of are : M25 = B6200; M25XP = B7200 ; M25XPB = F2400/F2560 ; M35BC = ??? Maybe a C34 or C36 MkII owner can fill in that blank !?!

A few thoughts

Noah · August 13, 2022, 02:01:17 PM

Ron—are you sure about the 25XP crossover to 7200 tractor? I looked up that tractor and it claims (only) 17hp. ?

Ron Hill · August 14, 2022, 01:26:35 PM

Noah : That's what I used to tell the Kubota parts people here in Fredricksburg Va / Virginia Northern Neck and they get me the correct part that I wanted!!!

A thought

KWKloeber · August 14, 2022, 08:48:13 PM

Quote from: truewind on August 10, 2022, 09:52:54 AM

I know that my M35B model is a V1305-E Kubota block. When I called a big Kubota dealer and gave them my serial number of my engine,

Universal engine serial number or KUBOTA engine serial number??
Most people go to a dealer with the incorrect serial number -- or with the wrong model number (e.g., M-35.)

Our engines (and their serial numbers) did NOT come from the Kubota agricultural (tractor) division, they came from the industrial side (who supplied end users like Kohler gensets, CAT, Bobcat, etc.). So although they are basically the same engine, yes, agricultural division dealers are sometimes blocked from infringing on industrial dealers' territories.