BX2350/BX24 Abrupt Reverse Stop

[Jim Shooz]

Can't help him with a schematic but am very interested in the solution.

 

[jesseb3@att.net]

I've been using Dodge Man's method of lifting the front pedal for a few years - it admittedly makes no sense, but it does make a difference. If you're a BXxx50 owner, do your neck a favor and try it. That being said, I still hope More Cowbell finds the solution. Assuming it's something a shade-tree mechanic can handle, I'll implement it.

 

[MoreCowbell]

The attached image shows what I have planned. It shows both the part diagram for the "ASSY COVER PORT BLO." and the hydraulic schematic of the HST courtesy of Oldnslo. The colored arrows show the areas on each diagram which I think match each other.


Unfortunately, the problem with just rigging up a needle valve between the green and blue ports is that they are right above the mid-PTO. Having fittings hanging out of them would prevent the mower shaft from being attached. I may temorarily just test my theory first without the mower attached. If it works, and I can identify an actual orifice size, I may try to drill an orifice into the forward check valve.

 

[sw03]

You would think kubota would have the hyd nailed down 10+ years later...sad.

 

[oldnslo]

I believe they do on the BX**60 series.

 

[oldnslo]

The attached image shows what I have planned. It shows both the part diagram for the "ASSY COVER PORT BLO." and the hydraulic schematic of the HST courtesy of Oldnslo. The colored arrows show the areas on each diagram which I think match each other.
View attachment 277657

Unfortunately, the problem with just rigging up a needle valve between the green and blue ports is that they are right above the mid-PTO. Having fittings hanging out of them would prevent the mower shaft from being attached. I may temorarily just test my theory first without the mower attached. If it works, and I can identify an actual orifice size, I may try to drill an orifice into the forward check valve.

Good luck with this. I worked on this problem on and off for a couple of years but did not want to ter the tranny apart due to warranty concerns. Could you install a fitting with orifice Vs the needle valve. This would give you a better idea of the orifice size but would require more work to adjust the size. I would guess that .020 would be the smallest diameter i would consider.

NOTE: This will detract from your top speed since you will always be losing some flow across the orifice which will also add more heat to the tranny.

Due to my needs changing I traded my BX last night so this is no longer an issue for me. The sudden stop was NOT part of the reason for trading up.

NOTE: I still have the work shop manual if you are interested let me know.

 

[TripleR]

I believe they do on the BX**60 series.

They do, our 2008 BX2660 is very smooth as was our 2003 BX2200, the problem seems to be limited to the BXxx50 Series.

 

[MoreCowbell]

This will detract from your top speed since you will always be losing some flow across the orifice which will also add more heat to the tranny.

I completely agree. That is actually why I was hoping to see a copy of the BX25/xx60 hydraulic schematic. I have the one for the BX23 which has orifices forward and reverse and does not have the problem, then they removed the forward one for the BX24/xx50 series and started having the abrupt reverse stop problem. Then they did something for BX25/xx60 to resolve it.

The thing that makes me hesitate to add the orifice is that while it would likely ease the problem, it would certainly bleed power like you mention. I'm wondering if that is why they removed it for the BX24/xx50 series to begin with. I'm very curious to see the BX25/xx60 schematic to see if they simply added the orifice back in and ate the power loss, or if they did something else with some kind of control valve that doesn't flow under normal forward motion. The parts diagram doesn't look any different though so I doubt its anything that fancy.

 

[MoreCowbell]

I believe the actual fix is in the linkage and the hydraulic damper on the foot control. The 50 series slowed the return from the forward position only. The 60 series slows it from both forward and rearward positions.

There are lots of different parts in the linkage. I would guess they would retro-fit.

After all my jabbering about this, I realize now that you are right. I've compared the HST hydraulic schematics for the 50 and 60 series and there was no change. I also did a "push test" on my BX2350 and a new BX2360 in the showroom and that suggests that a flow restrictor was not added to the forward circuit like I mistakenly thought (i.e. in high gear you can push the tractor forward, but not backwards).

I then noticed the enhanced pedal damper you mention. The new model does dampen from reverse to neutral whereas mine does not.

Using the Messicks parts diagrams I ID'ed the different parts. They are about $140 altogether. I'm not sure it is worth that much to me.

 

[MessickFarmEqu]

They do, our 2008 BX2660 is very smooth as was our 2003 BX2200, the problem seems to be limited to the BXxx50 Series.

It should be noted that the "problem" was not a mistake. Rather a choice they made based on customers crashing their tractors into stuff because the HST came to a stop slowly in the first place. Clearly it was not the best choice (nor where the plastic fenders) but when it comes to safty related stuff you get these knee jerk reactions.