Kubota B2320 Full Service

Cappyj

New member

Equipment
B2320 with FEL and Landpride Box Blade
May 6, 2015
1
0
0
TX
I have a Kubota B2320 HSD that I purchased in December 2014. I have been searching how to change the hydrostatic/transmission fluid and I have not been able to find anything showing how to perform this service. My tractor just hit the 50-hour mark and I decided to complete this service myself. As I did this, I documented what I did. Hopefully this will help someone else.

The front gear fluid can be drained through two drain plugs. One drain plug is on the left hand side facing the front of the tractor near the front wheel. I found it easier to drain by removing the left wheel.

The plug on the right side is near the right front wheel, facing the rear of the tractor. I also found it easier to drain by removing right wheel.

After draining all the fluid, I added 3 quarts and 8 ounces of 80W-90 gear oil to get it to the recommended level.

The manual shows that the B2320 has two drain plugs for the motor oil, which is wrong. There is only one drain plug. This drain plug is on the right side of the tractor, just above the crossbeam. It is easier to use a ratchet with an extension and remove the drain plug through the crossbeam hole. As the oil drains, it will make a mess as it gets all over the cross beam. After draining the oil, I added 3 quarts and 8 ounces of motor oil, which raised it to the recommended level.

The manual shows three drain plugs for the hydraulic/transmission fluid but there are four drain plugs. The two drain plugs on the rear axle that the manual shows are incorrect.

Following are the four drain plugs.

First one is near the PTO underneath the tractor. Photo 1.

Second drain plug is on the right rear axle. Photo 2.

Third is on the left rear axle. Photo 3.

The fourth drain plug is on the front of the tractor near the crossbeam. It is on the left side of the tractor. Photo 4.

By removing these four drain plugs, I was able to drain about 3 and ¾ gallons of fluid. I am assuming this because this is about the same amount of hydraulic/transmission fluid that I added to show the recommended level on the dipstick.
 

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papayala

New member

Equipment
B2320
Jan 9, 2025
1
0
1
Penngrove
Great Post CappyJ. It was very helpful.

I just completed the same process on my 2015 Kubota B2320, and it went exactly as described in the post. One thing I found both interesting and frustrating was that all of my bolts were different sizes. There was a 17mm, a 14mm, a 13mm, and a 12mm. That was a bit annoying, to say the least!

I was troubleshooting a sticky PTO lifter and followed the steps carefully:

  1. Check Fluid – It was low, so I topped it up.
  2. Check Speed Valve – Made sure it was open.
  3. Clean Linkages – Found a lot of debris (rocks and sticks!) around the area, so I cleaned it out.
  4. Lubricate Linkages – There was some noticeable rubbing in a few places near the lifter stop, so I made sure to lubricate those parts.
  5. Replaced Fluid and Filters – Replaced both filters and the fluid ($240 for supplies).
  6. Warm Up the Tractor – Started the tractor and purged the system by turning the steering wheel back and forth.
In just a few hours, working alone, I had everything up and running again. I ended up with about 3.5 gallons of waste fluid. There is a surprising and messy amount from the filters. After warming it up, I took the tractor for a spin, and it’s working great now.

One Extra Detail:

While I was removing a 17mm bolt just underneath the HST filter (the yellow filter on the port side of the tractor), I thought all the drain bolts would be the same size, but I was wrong. Underneath that bolt, I found a spring and a ball bearing. Luckily, I spotted the ball bearing as I was cleaning up the waste. I figured it was from the spring-loaded bolt mechanism and was able to get it back in place without any issues. That was a close call! That is when CappyJ's post was spot on. I did not study the pictures enough and pulled the wrong bolt.

Lesson Learned: Make sure the tractor warms up before use, and double-check all the bolts and parts during maintenance to avoid surprises.

All in all, everything is back to normal, and I’m glad I took the time to do the maintenance myself!