Oil & Fuel RCK54P23BX gearbox oil level

[Jeff H]

The Workshop Manual and the Operator's Manual seem to disagree with each other and are as clear as mud.

Which of the two plugs would you fill the oil level to? The smaller lower one or the larger upper one? Both are circled in yellow on this picture.

The Operator's Manual says to fill it to the level of the smaller lower one, which is where I ran it this summer, but now looking it at looks awful low.

The Workshop Manual says to fill it to upper larger one.

I am going with the upper larger one from now on.

 

[David_Kb7uns]

I have the RCK60-22BX deck that has a different gearbox.
It has three plugs.
The top one is the breather plug, side is for level check and the bottom one is the drain. From looking at your picture I would guess that the one on the lower right is the drain and the larger one to the left is the check and fill plug, looks like the top one is just the breather now. Hope this helps.

David Kb7uns

 

[Jeff H]

Hi David

Yes with your style of gearbox with 3 plugs the manual is clear, the oil level is at the upper plug of the 2 plugs on the side.

Oil fill level is my main concern, but the oil draining procedure is also somewhat questionable the way it is described in the manual(s).

The manual(s) for my gearbox say to drain it from the larger plug tilting the deck up long ways. I wasn't about to try to stand it up on the side like that. It seemed to drain just fine from the smaller plug while standing up the other way on my Larry's Mower Axles.

Jeff

 

[Jeff H]

Nobody out there with this same gearbox has any input?

 

[RMatty]

I have the same gear box lower plug is your check plug. Fill gear box until oil starts to run out of this hole. The upper plug larger bolt is your fill/drain plug if you fill your gear box to this bolt your gear box will overfilled and maybe blow a seal. The upper bolt is a breather plug. Hope this helps.

 

[Shmudda]

Matty, you are correct here.

What you guys have to understand is the gears in this box are picking up the lubrication and slinging it around to lube everything as they rotate.

TYPICALLY, you only fill a gearbox to just under the LOWEST seal, this way everything gets lubed as it should and the seal is never sitting in a pool of oil. If you overfill the gearbox and bring the level of lube over the seal lip leakage will most likely occur.

Keep in mind, seals need lubrication too so they don't wear out prematurely.

Craig

 

[Chilly807]

Matty, you are correct here.

What you guys have to understand is the gears in this box are picking up the lubrication and slinging it around to lube everything as they rotate.

TYPICALLY, you only fill a gearbox to just under the LOWEST seal, this way everything gets lubed as it should and the seal is never sitting in a pool of oil. If you overfill the gearbox and bring the level of lube over the seal lip leakage will most likely occur.

Keep in mind, seals need lubrication too so they don't wear out prematurely.

Craig

Sounds about right to me.

Chilly

 

[Jeff H]

I certainly understand the concept of overfilling and blowing out the seals, but the location of that lower plug just looks way too low to me.

 

[Chilly807]

Craig's right, the oil level only has to be high enough for the lowest gear to "dip" into the oil as it turns, this will spread a layer of oil over all the gear teeth in the transmission. If the oil level is too high it tends to churn the oil into a froth, causing aeration. The tiny air pockets actually cause damage to the gear teeth because they interrupt the oil film that should be there all the time, causing cavitation.

The gearbox will also be noisier and run hotter than normal if the oil level is too high.

If it were me, I'd drop in to see the dealer you got the tractor from and get them to show you how to check the oil. If the two manuals disagree, take them with you. If they scratch their head and seem to be guessing, then have a chat with the head office at Kubota.

The translation from Japanese to English seems to be a real challenge, thankfully it's one of the few weak points Kubota has.

Anyway, let us know what you find out.

Chilly

 

[Jeff H]

I got a response from Kubota customer satisfaction today. The fluid level is the lower hole. Thanks to everyone for their input.