My $10 BX Suspension Seat Mod

   / My $10 BX Suspension Seat Mod #1  

CHDinCT

Veteran Member
Joined
Jul 12, 2008
Messages
2,461
Location
Conn. & Florida
Tractor
Kubota BX25, Z422-KW
I haven't seen many if any complaints about the suspension in the BX seats but for me, the seat has always lacked adequate or even any real suspension to help with bumps and jolts. I never complained here about it, but in all honestly, my 18 year old Wheel Horse gave a better ride than the BX, especially in high range.

So, I have been cogitating for some time on how I might add some give to the seat on my BX25. A TBN search did not yield any prior mod's on the BX seat - most of the posts were about the replacement seat for the older version BX's. The BX seat appears to provide some suspension by the large compression springs at the rear corners of the seat frame, but these mostly provide upward force to keep the seat frame latch locked (the one you need to release to flip the seat up).

The only real suspension for the seat itself is a double torsion spring under the seat (see pic's). Don't know about other folks here but my wimpy 140lb body causes the torsion spring to bottom out (it looses all spring) so it really doesn't provide any suspension once you sit in the seat. My first thought was to add additional torsion springs to both rear corners between the seat bottom and the seat frame but I couldn't find the right type or stiffness locally or on-line. However, in the course of my search I stopped at a shop that repairs truck suspensions to see if they knew where I could find what I was looking for. Turned out one of the mechanics use to work at a Kubota dealership and told me how they use to weld on two added plates to the seat frame so they could mount two additional compression springs for many of the B and L series seats.

With that design in mind, I found two 1 3/8" (W) x 2 1/2" (H) x .135 gauge compression springs at my local hardware store. The unsprung distance between the seat bottom and the seat frame is about 2.25". As it turned out, these springs fit perfectly between the seat frame and the seat bottom with no need for an added mounting plate. For non-backhoe BX versions where the seat doesn't raise and rotate, you almost don't need any mounting hardware - the springs stay right in place. For my BX25, I used two fender washers and small 1/4" bolts to hold the springs in place when I raise the seat up.

After mounting the springs and taking the BX for a test drive, I found one fly in the ointment - the seat safety switch no longer engaged due to the added resistance, so I used some JB Weld and a few pieces of scrap steel to mount a couple of shims under the seat. I taped them in place first to check how many shims I needed to release the switch with the seat empty, but engage it when I sat in the seat. A little Kubota Grey spray paint for the shims and it all looks about OEM to me.

And the ride improvement is tremendous - a thousand percent better to me. I hated to use high gear for mowing or even transiting non-paved areas since the jolts went right through the tractor frame to my aching back. The added springs smooth things out nicely. I may have even kept my old BX1850 with the reverse jerk if the seat had more give and take. :laughing: The best part is the springs and fender washers were less than $10. I had the bolts and scrape metal, so that's all I needed once the solution was found. I really think for any non BX22/23/24/25 owners, you could just wedge the springs in and then maybe have to shim the seat switch depending on how much you weigh.

Pic's attached. Note that in pic 4, I was sitting in the seat when I took the picture.
 

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   / My $10 BX Suspension Seat Mod #2  
Congrats on the problem solving, particulary with the secondary 'shim' issue. Impressive and OEM as stated. :thumbsup:
 
   / My $10 BX Suspension Seat Mod #3  
very cool mod- your tractor is too clean though.. :D
 
   / My $10 BX Suspension Seat Mod #4  
When I mow on rough ground I support some of my weight with my forearms on the armrests, takes some of the shock out of my back. I may look at this kind of a mod on mine. Nice solution.
 
   / My $10 BX Suspension Seat Mod
  • Thread Starter
#6  
Hey, I work hard to keep the dirt on the FEL and BH buckets. OK, the tires too. :laughing:

Seriously, I blow it off with my leaf blower after each use so that helps, plus I don't mow with it partially due to it just being easier to jump on the Wheel Horse to mow vs mount the deck, and partially due to the formerly lousy ride it gave me. Now I'm anxious to mow with the BX again. I feel like I have a new tractor. I wonder why Kubota doesn't make this change? If it cost me $10, it would cost them half that with volume discounts.

If you can find the right springs, give it a try. You can wedge them in temporarily and use a piece of shingle or something to temporarily shim the seat switch if needed (or jumper it, but I didn't tell you that :D)
 
   / My $10 BX Suspension Seat Mod
  • Thread Starter
#8  
Oh, one other thing. The seat and seat frame weigh a lot more than it looks. When I first unpinned the seat to remove it, I went to lift it and though it must be stuck on something - nope, it just weighs a lot more than my mind's eye said it would. The non BH version probably weighs just a little less I'd guess.
 
   / My $10 BX Suspension Seat Mod #10  
I actually started a thread several months ago about the seating on the BX tractors and what can be done about them, I had installed an air ride seat but cause of the seat position and the addition of a cab made me sit way too high so I ended up putting the old seat back in.
 
 
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