BH77 backhoe stick cylinder juddering.

joeyj1617

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Equipment
Kubota L3301 LA525 loader BH77 backhoe
Nov 20, 2020
4
0
1
Alabama
I have a brand new BH77 with less than 20 hours on it and I have started to notice an issue with the stick cylinder. When the cylinder extends (moving the stick back towards me) I notice a shaking or juddering. I haven't noticed it until after 15 or 16 hours of use. The tractor is an L3301 and its also brand new. Sometimes when I curl the bucket on a tree root it will even pull the stick out instead of breaking the root. The whole backhoe also seems to be a little down on power. Any ideas as to what could be wrong with it?
 

Henro

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May 24, 2019
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First thought is you may have something going on with your control valve...

New tractor, call the dealer and discuss the issue. That is what I would do...
 
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joeyj1617

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Kubota L3301 LA525 loader BH77 backhoe
Nov 20, 2020
4
0
1
Alabama
That's what I was affraid of. I was hoping there were some things I could try before calling them. Lol.
 

85Hokie

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What RPM are you using high rpm or lower? Should not really matter - I too think it is in the control valve.
Vary the RPMS through the range and see if it helps or it is the same. As Henro said - dealer time to see and fix.
 

joeyj1617

New member

Equipment
Kubota L3301 LA525 loader BH77 backhoe
Nov 20, 2020
4
0
1
Alabama
What RPM are you using high rpm or lower? Should not really matter - I too think it is in the control valve.
Vary the RPMS through the range and see if it helps or it is the same. As Henro said - dealer time to see and fix.
I usually run it around 2000 or 2500 rpm. Is the control valve an easy fix or will it take the dealer a while?
 

85Hokie

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BX-25D ,PTB. Under Armor, '90&'92-B7100HST's, '06 BX1850 FEL
Jul 13, 2013
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Bedford - VA
I would hope they could find the solution and fix it quickly - then again it might be that $3 part that needs to be replaced that is out of stock and on backorder! Might just be some "trash" in the valve body.
I hope that they can come to you? OR must you get it to them?
 

joeyj1617

New member

Equipment
Kubota L3301 LA525 loader BH77 backhoe
Nov 20, 2020
4
0
1
Alabama
I would hope they could find the solution and fix it quickly - then again it might be that $3 part that needs to be replaced that is out of stock and on backorder! Might just be some "trash" in the valve body.
I hope that they can come to you? OR must you get it to them?
I'm not sure. They delivered it so maybe. If not they can pick it up. I'm going to try some things 1st. Someone here at work mention it may have some air in it.
 

Henro

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B2910, BX2200, KX41-2V mini Ex., Beer fridge
May 24, 2019
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Over the years I have changed different hoses on my Kubota backhoe and never worried about bleeding air out, and do not remember seeing any strange things happening after using the backhoe again.

Seeing that your issue just started, and the backhoe performed normally before the issue appeared, I would think it unlikely to be air in the system. If it were an issue with air in the system I would expect you would also be seeing something going on with your HST drive.

But that is just my guess. I would suggest you check everything that comes to mind. One time I had a problem with my B2910 soon after purchasing it. I talked to the dealer, and was about to have them pick it up, but decided on a whim to change the fuel filter, and that cured the intermittent issue with losing power, and then normal operation, losing power, repeat, repeat...
 

beckmurph

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Equipment
Kubota LX2610TLB/Woods finish mower/woods rotary cutter/
Aug 23, 2012
308
261
63
catlettsburg, ky
I have a brand new BH77 with less than 20 hours on it and I have started to notice an issue with the stick cylinder. When the cylinder extends (moving the stick back towards me) I notice a shaking or juddering. I haven't noticed it until after 15 or 16 hours of use. The tractor is an L3301 and its also brand new. Sometimes when I curl the bucket on a tree root it will even pull the stick out instead of breaking the root. The whole backhoe also seems to be a little down on power. Any ideas as to what could be wrong with it?
Does your tractor have position control?
Is so, check to see if position control is in the lowest position.
 

Henro

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B2910, BX2200, KX41-2V mini Ex., Beer fridge
May 24, 2019
5,783
2,969
113
North of Pittsburgh PA
Does your tractor have position control?
Is so, check to see if position control is in the lowest position.
Good point! I had some issues with my tractor moving normally with my 3PH backhoe on, because I did not lower the position control after installing the backhoe.

But I think the OPs backhoe is probably sub frame mounted so this may not be a concern...
 

beckmurph

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Kubota LX2610TLB/Woods finish mower/woods rotary cutter/
Aug 23, 2012
308
261
63
catlettsburg, ky
Good point! I had some issues with my tractor moving normally with my 3PH backhoe on, because I did not lower the position control after installing the backhoe.

But I think the OPs backhoe is probably sub frame mounted so this may not be a concern...
My bh77 on B2650 is mounted on a subframe.
 

lugbolt

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ZG127S-54
Oct 15, 2015
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Mid, South, USA
they are self bleeding, so air in the system would be a VERY remote possibility (consider it nonexistent)

how long has it been since the pins have been greased? If it were me (and it's not) I'd grease the hot fire out of them before you take it to dealer. Pins seizing can cause that issue.

Control valve problems are extremely rare.

I'm thinking it's a bent ram but it's not in front of me to inspect it.

As far as digging power, remember...it's a backhoe not an excavator. It has limits. In comparison to a U35 mini-ex, they are puny, no comparison at all not even in the same country!
 
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