Rebuilding Deck Gearbox RCK54-23ZG

MartyJones

New member

Equipment
L185
Aug 31, 2023
19
2
3
South MS
I am rebuilding the mower gear box and was wondering if I need to pack grease in the bearings as part of the rebuild or does the bearings just get their lubrication from the super udt fluid?

Also should I use permatex gasket maker to seal the gearbox half’s when input them back together?

Any tips or tricks would be greatly appreciated.
 

N3BP

Active member

Equipment
B7200DT, B7200HST-D, L2900GST, L3010 HST TLB
Sep 20, 2016
471
197
43
Lebanon, PA
No need to grease the bearings, just fill the box with 80W-90 to the specified level. If you're rebuilding spindle bearings, then you want to grease those well.

Not familiar with two-piece gearboxes (they are typically one piece castings), but I assume a thin layer of Permatex Grey or Black when reassembling would be wise.....
 
Last edited:

MartyJones

New member

Equipment
L185
Aug 31, 2023
19
2
3
South MS
No need to grease the bearings, just fill the box with 80W-90 to the specified level. If you're rebuilding spindle bearings, then you want to grease those well.

Not families with two-piece gearboxes (they are typically one piece castings), but I assume a thin layer of Permatex Grey or Black when reassembling would be wise.....
Thanks for the input. There are two different types of bearings in the case. Not sure if they are considered spindle bearings.

Here are links to them

 

JimDeL

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BX2380; R4 tires; 54" MMM; FEL w Pirahna bar; Ballast Box; BXpanded skid plate.
Aug 31, 2022
295
311
63
Austintown, Ohio
The manual calls for 80W-90 gear lube, NOT UDT in the gearbox.
 
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Yooper

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3901 LA525
May 31, 2015
1,529
529
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NE Wisconsin
If there was a gasket originally I would reassemble back with one. It would be critical for shaft end play.
 

JimDeL

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Equipment
BX2380; R4 tires; 54" MMM; FEL w Pirahna bar; Ballast Box; BXpanded skid plate.
Aug 31, 2022
295
311
63
Austintown, Ohio
Mine's a RCK54-23BX. Maybe there's a difference in gearboxes.
 

MartyJones

New member

Equipment
L185
Aug 31, 2023
19
2
3
South MS
Mine's a RCK54-23BX. Maybe there's a difference in gearboxes.
so I called my local Kubota shop and they told me the gearboxes come from the factory with super udt oil but they use 80-90w when they service them so that makes more sense. I will use 80-90w oil.

I am still not sure if I need to put any grease on the replacement bearings or not.

Any suggestions?
 

JimDeL

Well-known member
Lifetime Member

Equipment
BX2380; R4 tires; 54" MMM; FEL w Pirahna bar; Ballast Box; BXpanded skid plate.
Aug 31, 2022
295
311
63
Austintown, Ohio
so I called my local Kubota shop and they told me the gearboxes come from the factory with super udt oil but they use 80-90w when they service them so that makes more sense. I will use 80-90w oil.

I am still not sure if I need to put any grease on the replacement bearings or not.

Any suggestions?
The 80W-90 should be all the lube the gearbox bearings need. Fill and forget - until the next maintenance cycle.
 

PaulL

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Equipment
B2601
Jul 17, 2017
2,439
1,364
113
NZ
The 80W-90 should be all the lube the gearbox bearings need. Fill and forget - until the next maintenance cycle.
When @N3BP said "only on the spindle bearings" he mean on the spindles that drive the blades. They're not part of the gearbox, they're the ones driven by the belts. They have grease zerks on them. The bearings inside the gearbox are lubricated by the gearbox oil.
 

MartyJones

New member

Equipment
L185
Aug 31, 2023
19
2
3
South MS
When @N3BP said "only on the spindle bearings" he mean on the spindles that drive the blades. They're not part of the gearbox, they're the ones driven by the belts. They have grease zerks on them. The bearings inside the gearbox are lubricated by the gearbox oil.
That makes sense.
One last question, what is the best thing to clean the inside of the gearbox? I would like to get all the old gunk in there out. I plan on wiping it out as best as I can with rags. Is there a cleaner/degreaser that you guys would recommend ?
 

PaulL

Well-known member

Equipment
B2601
Jul 17, 2017
2,439
1,364
113
NZ
Brake cleaner is commonly used for things like this. Not sure why, other than perhaps lots of people have it lying around.
 

whitetiger

Moderator
Staff member

Equipment
Kubota tech..BX2370, RCK60, B7100HST, RTV900 w plow, Ford 1100 FWA
Nov 20, 2011
2,921
1,383
113
Kansas City, KS
Do not put any grease in the bearings.
Use a good RTV sealer in the case seam.
Use 80/90 in the gearbox.
 

GreensvilleJay

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BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
Apr 2, 2019
11,418
4,908
113
Greensville,Ontario,Canada
brake cleaner is cheap and works real good. Also real handy to kill boring bees, wasps and other flying ,stinging things !
 

GreensvilleJay

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Equipment
BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
Apr 2, 2019
11,418
4,908
113
Greensville,Ontario,Canada
It's what I use, as it'll 'flush out' the residue.
I used to use trichloroethelyene ??? Some big,long mouthful of letters. would get 45g drums of it for free (used coolant for SCR motor drives ). It worked GREAT at cleaning carbs and trannies and such.....
probably banned now of course.....