# Trick for Splitting Kubota Mower Deck Bevel Gear Case



## bcavender (Jun 23, 2018)

I have a RCK54P-23BX mower deck. It started dropping oil on the deck from the bevel gear case and I have removed the gear box from the deck.

The shaft was pretty solid until I pulled the box from the deck, but it now moves about a quarter inch of end play ... so I expect the top bearing has failed. I may have caught it semi-early as the gear oil show no metal particles.

The two halves of the bevel case appear to have been put together with a gasket sealant as some appears to have extruded and solidified outside the joint at various places around the shells.

I am puzzled as to how best get these case halves apart. Bolts have been removed, but light pulling/tapping have absolutely no impact on splitting these apart. I don't want to use something heavy to impact the case halves as I don't want to crack the aluminum case halves.

Has anyone found a trick to splitting this kind of case apart without destroying the case?

Thanks!

Bruce


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## sixbales (May 18, 2011)

Howdy Bruce, welcome to the tractor forum.

First thing to check for is snap rings that might be holding it together. I do not see any on the attached parts diagram. I guess I would try driving a sharp chisel at the corners. I often use (misuse) a sharp wood chisel. Don't get brutal. Post back if problem continues.


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## RC Wells (Dec 26, 2008)

The sealant used is similar to Yamabond 4, so it glues the sections rather well. Follow sixbales' instructions, and it may take quite a number of light taps around the union to get it to separate. 

When you reassemble, go to a Yamaha dealer and get a tube of Yamabond for the new seal. Some folks like Threebond 1211, but it is not as strong.


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## bcavender (Jun 23, 2018)

SIX/RC,

Thanks for responding!

I double checked for mechanical fasteners, but it appears that the bond is entirely due to the gasket seal. Tough stuff. I have been trying to avoid the 'brutal' route for a couple days now. I will step it up with a wood chisel. Sounds about right.

As an aside, I put a puller on the pulley and cranked it down until the pulley began to deform slightly ... not a sniff of a budge in the hub. 

In 40yr of putzing with a ton of construction equipment, this one takes the cake for being stubborn. All the way up there in the class of my Father-In-Law! _:^)_

Bruce


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## rhino (Jan 9, 2017)

Question, bcavender are you sure that the oil wasn't coming from the breather on top of gear box? I used to work at a Kubota dealer and we had a lot of those breather have oil seeping out. I talked to Kubota service guy for the northeast. He said that when the oil is hot the gears are flinging the oil at the location of gear box that the breather in screwed to. He said to remove breather and take two 90* elbow pipe fittings install them there and put the breather on top of them, that the oil can't hit the breather dead on. Make sure that the breather is still on top and that it will not be hit by any thing like when mower is raised. Now I have done this and it dose work. I do not know why it is not in any parts book as a upgrade.


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## bcavender (Jun 23, 2018)

Rhino,
The bottom seal was definitely the source of the oil and the breather on top was clean in this case ... but I can imagine what you are talking about. I wish that was my problem as it would be a quick fix.

Sixbales,

Your wood chisel idea worked like a charm and quite easily. I kept going around the periphery and it finally gave way after about 3-5 min of light taps. Thank you for the great tip.

Inside I was greeted by pristine looking bevel gears so that was a pleasant surprise that it had not eaten itself to pieces. It had rotated enough to wear the shims pretty thin.

I found that the bearing race for the blade shaft had been able to turn inside the case shells. I am guessing the wear there and in the bearing accounted for the end play. Interestingly there was no glue/sealant around that bearing, but the pto shaft bearings were gooped in tightly and seemed rock solid with almost zero play.

I suspect I will need to replace the shells and vertical bevel bearing to get that back in spec. Probably need to replace the vertical shaft bearing in the Center Pulley Holder underneath while I have this apart. That looks like it is going to be a trick to pull out.

Thanks for all the great comments and suggestions!!!

Bruce


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## bcavender (Jun 23, 2018)

After considering the options, I just ordered a new gearbox at $1400. The aluminum case shells were $334 per side so I would have almost $700 spent before bearings/seals/shim putzing/etc.

If Kubota designed a steel case for this bevel, this failure wouldn't have occurred. Love their engines, but I am not happy with their engineering here. Especially when you consider that everyone knows bevel gears deal with some punishing forces in a mower. I would definitely paid an extra $200 up front for a steel gear housing rather than soft aluminum. (Especially when you start to consider the cost of losing the use of the entire system for a couple weeks.)

That's one to file away for future attachment purchases.

Good luck to all!

Bruce


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## sixbales (May 18, 2011)

I replaced a gearbox on a Kubota G1900 many years ago. A few years later, the tractor frame broke in two which ended its mowing career. I welded the frame back together and still use the tractor for spraying pastures and fence lines. Plan on using it today for spraying fence lines and edge of roadway.

The Kubota engine and hydrostat seem to be virtually indestructible.


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## bcavender (Jun 23, 2018)

Never seen a tractor frame give out, but the floor board cracked on my BX24 on both sides for lack of a couple small steel supports. I have read a good number of people complaining about Kubota quality sagging over the last couple years ... especially electrical and computer components. Other than a few weak spots in the plastics, our 24 still starts/runs pretty smoothly.

Sounds like you got your nickle's worth out of your investment though!

Bruce


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## rhino (Jan 9, 2017)

There was a upgrade for the floor support and if plastic was cracked they replaced it also. All Kubota dealers were supposed to contract all owners as it was a safety issue 


Sent from my iPhone using Tractor Forum


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## bcavender (Jun 23, 2018)

Rhino,
Thank you! Had not heard that.

I ran a quick search to see if I could find further detail, but struck out.

Do you remember roughly when that happened?

I will be running by a dealer tomorrow ... will ask to see what they say.

Bruce


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## rhino (Jan 9, 2017)

about nine years or so ago. I was sent out and drove all over to places that we had sold to, and replaced them. I also did other upgrades to other models of Kubotas


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