Kubota B7100D gear shifting in high RPM?

[Aris]

Hi all!
I'm a newbie in this forum with a classic B7100D that is grinding when changing the gears.
The symptom varies: when cold the RPM is slow and the gears change with little grinding, but once it warms up, the RPM goes very high to the point that to change gears, I need to shut the engine off.
The mechanic's diagnosis is that my gearbox needs repair, but with my limited experience I believe I need first to address the high RPM problem. .
Questions for your expertise!
Could the increase in RPM be the culprit?
If so, is the fault in the governor, in the diesel pump, or in both?
If so, can I adjust them or overhaul them if I get the needed parts?
Thanks ahead!!
Aris

 

[TheOldHokie]

Hi all!
I'm a newbie in this forum with a classic B7100D that is grinding when changing the gears.
The symptom varies: when cold the RPM is slow and the gears change with little grinding, but once it warms up, the RPM goes very high to the point that to change gears, I need to shut the engine off.
The mechanic's diagnosis is that my gearbox needs repair, but with my limited experience I believe I need first to address the high RPM problem. .
Questions for your expertise!
Could the increase in RPM be the culprit?
If so, is the fault in the governor, in the diesel pump, or in both?
If so, can I adjust them or overhaul them if I get the needed parts?
Thanks ahead!!
Aris

You only shift gears with the tractor sitting still. If you are trying to shift gears with the tractor in motion you can't. Engine RPM does not matter. and if your mechanic believes otherwise seek better advise.

Dan

 

[Aris]

You only shift gears with the tractor sitting still. If you are trying to shift gears with the tractor in motion you can't. Engine RPM does not matter. and if your mechanic believes otherwise seek better advise.

Dan

Thanks for the reply, Dan, I apologize but my English is not that good. The problem I described is not while the tractor is moving, but when it is stationary/still.
I start it from cold and the RPM is low, seems perfect to me and I can shift in any gear with almost no grinding. This is how it has been for the 10 years I'm using it.
Progressivelly in the last year or so(?), once the engine has reached operating temperature, when at idle the rpm has increased VERY much. It is way above compared to when the engine was cold. If I now try (while stationry/still) to shift, it refuses to go into any gear, with an awfull amount of grinding.
There is no smoke or power problem when operating on the field, it is just the idle that once warmed up, has increased very much and wont allow any gear to engage when standing.
Hope it makes more sense now!

 

[85Hokie]

Have you checked the linkage for the clutch?

AS for the engine increasing as it gets "warm" - I am hoping the throttle is moving without you moving it.
IF you pull/push the throttle back towards idle - does the RPMS go back down? OR is the high idle the lowest you can set the engine with the hand throttle?

Look at the linkage on the right side - move the throttle arm ( engine off) does it move freely or is it stiff to move?

 

[Aris]

THANKS FOR THE HELP!


Have you checked the linkage for the clutch?
YES REPEATEDLY, NO PROBLEM THERE

AS for the engine increasing as it gets "warm" - I am hoping the throttle is moving without you moving it.
NO, IT IS NOT AND IT RETURNS TO FULL RETREAT

IF you pull/push the throttle back towards idle - does the RPMS go back down? OR is the high idle the lowest you can set the engine with the hand throttle?
EVEN IF I MANUALLY PULL/PUSH THE THROTTLE LINKAGE ALL THE WAY BACK TO IDLE, THE RPM WILL STAY VERY HIGH WHEN WARMED UP

Look at the linkage on the right side - move the throttle arm ( engine off) does it move freely or is it stiff to move?
IT MOVES FREELY
I READ ABOUT GOVERNOR ADUSTMENT, COULD THIS BE MALFUNCTIONING OR NEEDS ADJUSTMENT?
ALSO ABOUT SOME SPRINGS IN THE INJECTOR PUMP, COULD THOSE BE FAULTY?

 

[Russell King]

Check out the linkage for the fuel foot control pedal if you have one.

 

[TheOldHokie]

Thanks for the reply, Dan, I apologize but my English is not that good. The problem I described is not while the tractor is moving, but when it is stationary/still.
I start it from cold and the RPM is low, seems perfect to me and I can shift in any gear with almost no grinding. This is how it has been for the 10 years I'm using it.
Progressivelly in the last year or so(?), once the engine has reached operating temperature, when at idle the rpm has increased VERY much. It is way above compared to when the engine was cold. If I now try (while stationry/still) to shift, it refuses to go into any gear, with an awfull amount of grinding.
There is no smoke or power problem when operating on the field, it is just the idle that once warmed up, has increased very much and wont allow any gear to engage when standing.
Hope it makes more sense now!

Increasing engine RPM is one problem but it is not your shifting problem. The clutch disengages the transmission from the engine when you push the pedal down to shift. If the clutch does not disengage your gears will grind. Clutch disks are known to stick to the flywheel if allowed to sit for extended periods of time. That would be my first guess. A missadjusted or worn clutch linkage is another possibiity. Engine RPM is not the cause of your shifting problem.

Dan

 

[Aris]

Check out the linkage for the fuel foot control pedal if you have one.

I HAVE TRIED OUT DISCONNECTING THE LINKAGE COMPLETELLY AT THE ENGINE/PUMP END, BUT THE RPM DID NOT COME DOWN.
TO MY AGNOSTIC SELF, IT SEEMS THAT IT GOES UP WHEN THE ENGINE REACHES OPERATING TEMPERATURE.

 

[Russell King]

The clutch linkage can be adjusted to engage earlier in the pedal movement

There is a sliding rack in the injector pump that may be sticking

 

[RalphVa]

Adjust your clutch linkage.

 

[torch]

Do you also have grinding when engaging the PTO with the engine running? If you depress the clutch on level ground, does the tractor still try to creep forward? Those would be signs pointing to a clutch issue. Ensure the throwout bearing is properly greased -- the grease zerk is underneath the tractor and easily missed. The clutch may have warped a bit over the years, in which case it will need replacement -- eventually. For now, you might get away with adjusting the clutch for more free play. But of course, you must ensure you don't adjust it so tight that it fails to release completely.

As for the idle speed, how do you shut it off? If it shuts off by pulling the lever all the way down, then I think the linkage itself is properly adjusted and the problem is a sticking governor. In particular, there is a spring and lever assembly that is supposed to provide a little extra fuel when starting. If that is sticking, it would cause a high idle. I don't know of any adjustment -- it strictly relies on spring tension and as the spring gets weaker, there is less effect, not more.

 

[Aris]

There is a sliding rack in the injector pump that may be sticking

THAT sliding rack SEEMS TO POINT IN THE RIGHT DIRECTION, THANKS! I HAVE DOWNLOADED A MANUAL FROM manuals 247.com IN THE PAST, BUT IT'S DETAILS ON THE INJECTOR PUMP ARE SIMPLY INADEQUATE. CAN YOU PLEASE POIN ME IN THE RIGHT DIRECTIONS OF A MANUAL TO TACKLE THIS?

 

[Aris]

Do you also have grinding when engaging the PTO with the engine running? If you depress the clutch on level ground, does the tractor still try to creep forward? Those would be signs pointing to a clutch issue. Ensure the throwout bearing is properly greased -- the grease zerk is underneath the tractor and easily missed. The clutch may have warped a bit over the years, in which case it will need replacement -- eventually. For now, you might get away with adjusting the clutch for more free play. But of course, you must ensure you don't adjust it so tight that it fails to release completely.

As for the idle speed, how do you shut it off? If it shuts off by pulling the lever all the way down, then I think the linkage itself is properly adjusted and the problem is a sticking governor. In particular, there is a spring and lever assembly that is supposed to provide a little extra fuel when starting. If that is sticking, it would cause a high idle. I don't know of any adjustment -- it strictly relies on spring tension and as the spring gets weaker, there is less effect, not more.

THANKS FOR THE HELP, I HAVE EXHAUSTED ALL CLUTCH RELATED ISSUES.
YES IT SHUTS OFF PROPERLY WHEN PULLING THE LEVER BACK SO AGAIN IT SEEMS LIKE A STICKING GOVERNOR AND/OR INJECTOR PUMP. WHERE CAN I FIND INSTRUCTIONS ON DISMANTLING THE GOVERNOR? ON IT'S SPRING, IS IT A NOS SPECIIFIC SPRING WHERE CAN I FIND AND ORDER ONE IF THEY ARE STILL AROUND?

 

[North Idaho Wolfman]

Hi all!
I'm a newbie in this forum with a classic B7100D that is grinding when changing the gears.
The symptom varies: when cold the RPM is slow and the gears change with little grinding, but once it warms up, the RPM goes very high to the point that to change gears, I need to shut the engine off.
The mechanic's diagnosis is that my gearbox needs repair, but with my limited experience I believe I need first to address the high RPM problem.
Questions for your expertise!
Could the increase in RPM be the culprit?
If so, is the fault in the governor, in the diesel pump, or in both?
If so, can I adjust them or overhaul them if I get the needed parts?
Thanks ahead!!
Aris

First please don't type in all CAPS as that is considered yelling and rude.

The RPMs and the gears grinding are and are not related.
You probably just don't notice it at lower RPM's because it's less violent and has less force.
If you can get it in gear and it stays in gear and moves fine when in gear it's not a transmission issue.
It is a clutch adjustment issue, the clutch is dragging and at high RPM's it's trying to spin the transmission and at lower RPMS it's less force thus less noticeable.

Now for the High RPM's.
Three most likely causes:

Bad or worn injectors, as they heat up the springs get week and they push more fuel easier.
New injectors would not be a bad starting point, it's certainly not going to hurt it.

Damaged or worn injection pump, either get a new pump or have yours rebuilt.
It's not a rack issue because you can start and stop the tractor normally, if the rack was stickling it wouldn't shut down or start properly.
It's not something you're going to be able to do without the proper tolerance measuring and test equipment.

The last cause is the governor might be damaged, and let me stress this that is very very rare on a Kubota, they just don't fail.
The governor is not a simple spring to be removed, it's much more complicated than that, and to get to it it's requires removing the whole front of the engine.

With you being all the way over in Greece, help all of us help you out, make a video of it doing what it's doing, 2 part, cold operation and warm operation, show the throttle linkage being moved (at the motor side) in both cold and warm.
Post the video on You Tube and then give us a link to see it.
I've done this before it helps tremendously.

 

[Aris]

First please don't type in all CAPS as that is considered yelling and rude.

The RPMs and the gears grinding are and are not related.
You probably just don't notice it at lower RPM's because it's less violent and has less force.
If you can get it in gear and it stays in gear and moves fine when in gear it's not a transmission issue.
It is a clutch adjustment issue, the clutch is dragging and at high RPM's it's trying to spin the transmission and at lower RPMS it's less force thus less noticeable.

Now for the High RPM's.
Three most likely causes:

Bad or worn injectors, as they heat up the springs get week and they push more fuel easier.
New injectors would not be a bad starting point, it's certainly not going to hurt it.

Damaged or worn injection pump, either get a new pump or have yours rebuilt.
It's not a rack issue because you can start and stop the tractor normally, if the rack was stickling it wouldn't shut down or start properly.
It's not something you're going to be able to do without the proper tolerance measuring and test equipment.

The last cause is the governor might be damaged, and let me stress this that is very very rare on a Kubota, they just don't fail.
The governor is not a simple spring to be removed, it's much more complicated than that, and to get to it it's requires removing the whole front of the engine.

With you being all the way over in Greece, help all of us help you out, make a video of it doing what it's doing, 2 part, cold operation and warm operation, show the throttle linkage being moved (at the motor side) in both cold and warm.
Post the video on You Tube and then give us a link to see it.
I've done this before it helps tremendously.

First thank all of you for volonteering your valuable assistance!!! The B7100D is on an island on the Argean and weather permitting I will go there next weekend and as suggested will make a video of the problem.
I'll ask my son to load it on You Tube and will post here the link.

It is good news about a governor being a rare thing as removing the front of the engine sounds a very big job! I spoke to a local diesel mechanic there who told me I could repair/service the injector pump for 150 to 200 Euros, but I wonder since I work my self on classic cars if I can do this myself if i get the parts and no specific tools or adjustments are needed.

BTW I apologize for the caps, sorry no offence intended!

 

[torch]

I HAVE DOWNLOADED A MANUAL FROM manuals 247.com IN THE PAST, BUT IT'S DETAILS ON THE INJECTOR PUMP ARE SIMPLY INADEQUATE. CAN YOU PLEASE POIN ME IN THE RIGHT DIRECTIONS OF A MANUAL TO TACKLE THIS?

I'm guessing you downloaded the Intertek "manual", which is woefully inadequate. You can download the Kubota B7100 HST Workshop Manual from here. I realize yours is a geared tractor, but I believe the injection pumps are the same. There is a comprehensive 9 page illustrated description of the injection pump and related controls starting on page 107.

(As for the use of all-caps: meh, I assume you are old. I too remember the days when official documents were all-caps. It was seen as more dignified and reduced confusion. My first daisy wheel printer didn't even have lower case characters. These young pups who didn't learn to type until ASCII extended the available character set just don't appreciate the privations we experienced. Half of them can't spell, either. )

 

[Aris]

I'm guessing you downloaded the Intertek "manual", which is woefully inadequate. You can download the Kubota B7100 HST Workshop Manual from here. I realize yours is a geared tractor, but I believe the injection pumps are the same. There is a comprehensive 9 page illustrated description of the injection pump and related controls starting on page 107.

(As for the use of all-caps: meh, I assume you are old. I too remember the days when official documents were all-caps. It was seen as more dignified and reduced confusion. My first daisy wheel printer didn't even have lower case characters. These young pups who didn't learn to type until ASCII extended the available character set just don't appreciate the privations we experienced. Half of them can't spell, either. )

Hey Torch really thank you, yes at 75 I'm certainly old but still work by myself on classic cars since too many years ago! I bought the D7100D by choice since it is a classic as well and I love using it and of course maintaining it to the degree I can since I only have worked on gasoline cars.
I tried the Link you were kind to put above but my Chrome will not open it, I tried copy/past it but got nowhere. If there is a workaround please let me know!
Aris

 

[RCW]

Try this link. Same site as Torch copied, just the main page on the site.

www.kubotabooks.com

Over 600 free Kubota manuals. A library of free manuals and parts diagrams compiled by Kubota tractor owners. All free to download instantly. No tricks, no subscriptions, no sign ups, no weird apps or software to install.

kubotabooks.com

 

[torch]

I tried the Link you were kind to put above but my Chrome will not open it, I tried copy/past it but got nowhere. If there is a workaround please let me know!
Aris

Strange. Try right-clicking and selecting "Save Link As". Works in Chrome on my computer. It is a large PDF file. Here is the link again:

http://www.kubotabooks.com/AutoIndex/index.php?dir=Tractor%20Owners%20Manuals/&file=B7100HST_WSM_complete.pdf

Hmmm. Looking at the link above, I wonder if the problem is that Kubota Books uses spaces in their URLs. Some systems don't like that, and replace the space with %20. Other systems take %20 literally instead of translating back.

Try this instead (no spaces in the name, just underscores. Should work with everything.):

https://picturehosting.verhey.org/Kubota/B7100HST_WSM_complete.pdf

(Aaaand we're back to discussing character sets... )

 

[Aris]

The second one worked fine, whow it is amazing! better late finding it than never! again thanks a million!!!!