Gearbox oil change on RCK54P23BX deck

BillK01

Member

Equipment
BX2360, FEL, LP 1560 back blade, Front mount snow blower, Ferris ISX800 ZTR
Mar 17, 2017
169
0
16
Near Pittsburgh, PA
So last weekend I changed the oil in the gearbox of my 54" mower deck. (RCK54P23BX)

The manual says it holds .16 qts. The manual also says it should be filled to just below the check port.

Well .16 quarts didn't even come close. Once it was all said and done I had to use almost half a quart to get the level to just under the check port.

So at this point I'm not sure if I've overfilled it or not - or if it's nothing to worry about.

Anyone have any ideas? Should I drain it all out and start over?
 

Delmar

Member

Equipment
G1900 / Kubota BX
Sep 24, 2015
180
11
18
Bluegrass State
I have a 54" deck also, but for a GR series. Just checked my manual and, like yours, it calls for .16 quarts. Since that's just 5 ounces, I can't bring myself to believe that's enough oil so I fill to the bottom of the check plug. If you read through the service manual there are enough translation issues that I wouldn't be totally surprised if there was a typo -perhaps it's supposed to be .16 gallons, that would be about 20 ounces which seems about right to me.

Anyway, the check plug is there for a reason. I'd fill until oil starts to seep from the bottom plug.
 

redfernclan

Member
Jul 18, 2014
155
4
18
Sweet home, Oregon
One more thing to consider. I work at a 1.5 million sq ft retailer distribution center. We have miles of conveners and hundreds of reducers. Some are sealed and some are vented. Since air expands at a greater rate than oil, the sealed units are filled about 3/4 to 7/8 full. If they are filled half way, the air will expand at a greater rate and build more pressure inside the reducer. We found out the hard way that on a sealed reducer, more oil is called for in the reducer. In our case they were Winsmith reducers and sealing the reducer was an option for some models. We were trying to be good mechanics and change the oil after a year but when we refilled them, we went with the normal level plugs. When they warmed up, they built up more pressure and promptly leaked out the seals. I guess we should have read the instructions. What I am getting too is if it is not a vented reducer, more oil is better. It goes against the grain with most people because you keep thinking the higher the level, the more chance to come out of the seals. Not so much.
 

BillK01

Member

Equipment
BX2360, FEL, LP 1560 back blade, Front mount snow blower, Ferris ISX800 ZTR
Mar 17, 2017
169
0
16
Near Pittsburgh, PA
Well here I am a couple of weeks later and now it appears I have small oil drip from the gearbox (it's directly under the deck when I pull out the tractor to mow).

I'm hoping if I drain it and replace it with the .16 qts per the manual it will stop. Anyone think maybe I did overfill it after all and ruined a seal? I hope not.
 

whitetiger

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Kubota tech..BX2370, RCK60, B7100HST, RTV900 w plow, Ford 1100 FWA
Nov 20, 2011
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113
Kansas City, KS
Proper fill is to the bottom of the upper plug. Ignore the capacity listed in your manual, many are incorrect due to translation. You just have a failed or damaged output shaft seal.

You need to remove the gearbox and replace the input and output shaft seals.

Remove the belt from one outer pulley, disconnect PTO shaft from the gearbox. Remove center blade, spindle shroud cup, snap ring and drive hub from the center spindle. Remove the 4 mounting bolts holding gearbox to mounting brackets. Lift gearbox from the deck.

Remove the seal plug from the top of the gearbox and then remove the snap ring on top of the output gear. The output shaft will now just slide out of the box. Clean it up, R&R shaft seals and reassemble. You can reuse the top seal plug if you want.
 

D2Cat

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Mar 27, 2014
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Whitetiger, you describe that with such detail I'm guessing you've done that a time or two!:D

I appreciate your posts. Always concise and to the point, speaking from your experience. Kind of like that old E.F.Hutton commercial, "When E.F.Hutton talks people listen".

I'll sneak in on you one of these days!
 

whitetiger

Moderator
Staff member

Equipment
Kubota tech..BX2370, RCK60, B7100HST, RTV900 w plow, Ford 1100 FWA
Nov 20, 2011
2,942
1,399
113
Kansas City, KS
Whitetiger, you describe that with such detail I'm guessing you've done that a time or two!:D

I appreciate your posts. Always concise and to the point, speaking from your experience. Kind of like that old E.F.Hutton commercial, "When E.F.Hutton talks people listen".

I'll sneak in on you one of these days!
D2Cat: Yes, I have done these several dozens of times..:D:D
You are welcome to sneak in any time.
 
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SHWERDNA

New member

Equipment
Kubota L2501, Kubota 2360, Kubota RCK54-23BX Mowing Deck, Kubota 2750D Snow Blow
Apr 20, 2022
1
0
1
Vermont
So last weekend I changed the oil in the gearbox of my 54" mower deck. (RCK54P23BX)

The manual says it holds .16 qts. The manual also says it should be filled to just below the check port.

Well .16 quarts didn't even come close. Once it was all said and done I had to use almost half a quart to get the level to just under the check port.

So at this point I'm not sure if I've overfilled it or not - or if it's nothing to worry about.

Anyone have any ideas? Should I drain it all out and start over?
Actually, there are 3 plugs on your gearbox. 1. the fill plug, at the top 2. the fill level plug on the side 3. the drain plug, right below the fill level plug. When you fill the gearbox, you should just add oil with the 'fill level plug out (number 2), and when the oil starts to come out...it's full.
 

armylifer

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BX1860, FEL, RCK54P MMM, BB1548 Box Scraper, Quick Hitch, Piranha Bar, BX6315
Mar 26, 2013
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Thurston County, WA
I have the same MMM as the OP and what I always do with mine is put in the same amount that was drained. This practice has worked for me the past 9 years that I owned the mower. I will change this procedure only if I start to see any leaks. So far, I have never seen any oil under the mower.
 

xrocketengineer

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BX1880, FEL, Grapple, 36 in. Forks, 48in. MMM, Quick Spade, Ripper
Nov 14, 2020
754
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Merritt Island, Florida
Well, when I did the oil change on mine the first time, I figured that I would make a hell of a mess using the drain plug. So, I did it the hard way, I used a syringe with a piece of hose through the fill hole. After I drained most of the oil, I noticed that the hose could reach deeper and lower than where the drain plug was. I drained some more and some black nasty stuff came out from ( I guess) next to the seal. For the second oil change, I used the same process and the oil that came out looked like new.