Kubota BX1880, BX2380, BX2680 Mid-Mount Mower Deck Maintenance

BX1880 / BX2380 / BX2680 Owner Service Guide

The BX80 series takes the RCK48-18BX 48-inch, RCK54-23BX 54-inch and RCK60B-23BX 60-inch mid-mount side discharge decks. All three are serviced the same way: grease the fittings each day the deck is used, check the gearbox oil, and change the gearbox oil after the first 50 hours and every 150 hours after that. The RCK60B-23BX has one extra grease fitting on the balance shaft.

Daily checks

Replace any worn, damaged or missing parts before mowing. Dry the deck completely before storing it, or the pulleys will rust.

Greasing

Grease the following points each day the mower is used. Wipe each fitting clean first and wipe off the excess after.

Also put a light coat of grease on the universal joint spline.

For more on choosing a grease, see our video:

Gearbox oil

The gearbox holds 0.4 L (0.42 qt.). Check the label on top of the gearbox before adding oil. A rectangular label means SAE 90 gear oil, API GL-5. An octagonal label means SAE 10W-30 gasoline engine oil, API SH or higher. Do not mix the two.

To check the level:

1. Park the mower on a level surface.
2. Remove the check plug bolt on the side of the gearbox. Oil should be visible at the opening.
3. If it is low, add oil through the filler plug until it reaches the check plug opening.
4. If it is too high, let oil drain out of the check plug opening until it stops.
5. Reinstall the plugs.

To change the oil, after the first 50 hours and every 150 hours after that:

1. Park the mower on a level surface and place a pan under the gearbox.
2. Remove the drain plug and the filler plug and let the oil drain.
3. Reinstall the drain plug.
4. Fill through the filler plug until oil reaches the check plug opening.
5. Reinstall the check plug and the filler plug and wipe the gearbox clean.

The initial 50-hour change does not reset the 150-hour interval.

Check the gearbox oil seals once a year and replace them if they are cracked, hardened or leaking. Replace the seals every four years regardless of condition.

Removing and installing the deck

Blade and belt work starts with taking the deck off the tractor. Removal and installation are shown in our video:

Blades

Keep the blades sharp. Sharpen a blade when the cutting edge is rounded (B below). Replace it when it is cracked, bent or worn thin at the edge (C). Replacement blades are K5181-71940 for the RCK48-18BX, K5351-99040 for the RCK54-23BX and K5371-99040 for the RCK60B-23BX.

To swap positions and extend blade life, move the blades as shown below at each sharpening.

1. Remove the mower from the tractor and turn it over to expose the blades.
2. Wedge a block of wood between the blade and the deck, or hold the pulley nut with a box wrench, so the spindle cannot turn.
3. The blade bolts have right-hand threads. Turn them counterclockwise to loosen.
4. Clamp the blade in a vise and file along the original bevel with a large mill file until sharp.
5. Check balance by putting a small rod through the center hole. File the heavy side until the blade balances.
6. On the RCK54-23BX and RCK60B-23BX, install the blade with the lock washer and two cup washers. On the RCK48-18BX, install it with the spindle guard and one cup washer. Check that the cup washers are not flattened or worn and replace them if they are, or the blade will slip.
7. Torque the blade bolts to 76 to 86.7 ft-lbs. Replace a damaged bolt with K5700-34375 on the RCK48-18BX or K5371-34372 on the RCK54-23BX and RCK60B-23BX.

Belt replacement

1. Remove the mower deck from the tractor.
2. Remove the left and right belt covers.
3. Clean around the gearbox.
4. Take the belt off the tension pulley.
5. Remove the right-hand bracket that mounts the gearbox to the deck and slip the belt over the top of the gearbox.
6. Install the new belt in reverse order. The belt is K5345-34710 for the RCK48-18BX, K5782-34710 for the RCK54-23BX and K5763-34712 for the RCK60B-23BX. Torque the bracket bolts to 57.1 to 66.5 ft-lbs.

Storage

At the end of the mowing season, remove the belt covers, slack the drive belt, clean the pulleys and wipe them with an oiled rag, and clean grass and dirt off the deck. Leave the belt slack until the next season.

Parts

Parts catalogs: RCK48-18BX, RCK54-23BX, RCK60B-23BX. To have service done at Messick's, schedule service.

Related

• Tractor grease points
• Front loader maintenance
• Video: Differences between the RCK60B-23BX and RCK54-23BX decks
• Video: How to level a mower deck
• BX Owner Service Guide