M7040 hydraulic shuttle questions

[Ruskyhog]

I have a M7040 with the hydraulic shuttle and have a couple questions
1. I know you don’t have to use the clutch with the hydraulic shuttle, so is it best to go to stop in neutral either for a second or two before changing directions, come to a complete stop before changing directions or just go straight to the opposite direction position with the lever without stopping in neutral first?
2. When changing directions with the shifter without using the clutch is it normal for there to be a slight pause before the tractor lunges in the selected direction?
Thanks
Josh


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[greenacresnorth]

yes there will be a delay, its worse when cold. coming to a complete stop will make for smoother shifts and a negatable amount of wear less but it is all multi disk wet clutch packs so its peanuts. big thing to make things last is use your foot throttle and let engine slow you down before making a direction shift like in your truck, leaving the engine wide open will build allot of heat and could cause premature damage especially if done in higher gears.

 

[russell.still.5]

I go straight from one direction to another without stopping in neutral. I’m sure it is better for the clutch to stop before changing direction but it was designed to go straight from one direction to the other.

It is normal for the tractor to pause before heading in the other direction. At least all of the one lbs I have operated were that way. It is way worse when cold like mentioned above.


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[Dave_eng]

I have a M7040 hydraulic shuttle new in 2012.

I have also been a motorcycle rider for 55 years.

Both share the same multi plate clutch design.

The lesson I learned from many motorcycles is that the steel disks have tabs which tie the disk to the outer hub while the friction disks have tabs along their inside circumference to engage the other part of the clutch assembly.

When all are pressed together, the inside and outside tabs provide power transmission. When you abuse a motorcycle clutch, what I found was that the outer tabs on the steel disks cut a notch into their hub over time and then getting the clutch to release is a problem.

I treat my shuttle shift with respect. I am not rushing trying to make a deadline. I want my new tractor to be trouble free until I am too old to use it. The operators' manual says it can be shifted while the tractor is moving slowly. My concern is that moving slowly in a low gear at a high throttle setting, will impose spike in load. I acknowledge being much more conservative. I lived with used, old tractors for decades and now that I have a new one, I am determined to treat it in the best way possible

I avoid any sudden load on it. Likely you can use it as some have described but..... if the M7040 is not as tough as the models others have their experiences on, then you are the one left with the big issue.

Dave

 

[Tx Jim]

I've loaded/unloaded many 100's of rd bales with my M7040 hyd shuttle tractor. I normally utilize 4th or 5th gear while controlling engine rpm's with foot accelerator pedal. I lower engine speed before shifting shuttle.

IMHO the springs in the hub of the damper clutch is what takes a lot of the abuse when changing directions while moving.

I agree shuttle hesitates when changing directions due to the modulation valve built into the control valve.

 

[Dave_eng]

This post is not meant to argue with the ideas put forward by others.

I am providing this material regarding clutch design as this was the purpose of the springs in clutch disks we were taught as mechanical engineers many years ago.

Things may have changed and I do not know the parameters Kubota's engineers were trying to achieve.

Please consider these two pages as just educational.

Dave

 

[greenacresnorth]

Dave, these things don't actually have a dry clutch on the engine, they have a damper that is designed to take up engine pulse and dampen gear rollover not so much shifting stresses. there is a mechanically programmed clutch closure time set up in the shifting modulation valve, this is what takes up the shifting stresses. most all your new car and truck auto trannys that run planetary gear sets and multi disk plate clutches work the same way, they shift all gear sets with locked converter and there is a mechanically or electronically programmed slip dialed in that takes up the shifting stress.

 

[Dave_eng]

Dave, these things don't actually have a dry clutch on the engine, they have a damper that is designed to take up engine pulse and dampen gear rollover not so much shifting stresses. there is a mechanically programmed clutch closure time set up in the shifting modulation valve, this is what takes up the shifting stresses. most all your new car and truck auto trannys that run planetary gear sets and multi disk plate clutches work the same way, they shift all gear sets with locked converter and there is a mechanically or electronically programmed slip dialed in that takes up the shifting stress.

Please read my post #4 in this thread. My goal in asking you to do this is, with your further comments, I can improve my posts so that readers do not misunderstand my message. I have a lot of technical knowledge from years of education and training, but I always need to learn more from people like NIW

In my Eaton related post, I was just trying to provide technical information related to clutches in general that, in my experience, most owners and mechanics do not understand why these rotational movement springs are present. In my younger days first working on cars, I was told that these springs were present to soften the clutch engagement. Some clutch disks had them some did not even for the same car and power-train. No one I knew could explain why the difference.

Power transmission technology is changing rapidly with Kubota now using CVT's on some models. Formula 1 cars' transmissions are actually in two gears at the same time which is impossible in more typical cars' transmissions even dual clutch ones.

I like learning. I like sharing knowledge, I want to get better at paying it forward regarding the education I have received on this forum and others.

Dave

 

[North Idaho Wolfman]

Dave, these things don't actually have a dry clutch on the engine, they have a damper that is designed to take up engine pulse and dampen gear rollover not so much shifting stresses. there is a mechanically programmed clutch closure time set up in the shifting modulation valve, this is what takes up the shifting stresses. most all your new car and truck auto trannys that run planetary gear sets and multi disk plate clutches work the same way, they shift all gear sets with locked converter and there is a mechanically or electronically programmed slip dialed in that takes up the shifting stress.

SAY WHAT????
Are you saying a M7040 does not have a mechanical dry clutch?

 

[Tx Jim]

SAY WHAT???? :
Are you saying a M7040 does not have a mechanical dry clutch?

NIW
Please explain what you imply by stating "mechanical"???

Yes a Kubota M7040 with hyd shuttle has a dry damper clutch with torsion springs.

 

[North Idaho Wolfman]

Done stuck my foot in it didn't I.
I'm blaming this one on Dave.
Teach me to look at the first M7040 specs I look at!
Your right a M7040HXXX does not have a clutch disk.

......Dave..... Your M7040HXXX doesn't have a multi disk clutch!

 

[Tx Jim]

Done stuck my foot in it didn't I.
I'm blaming this one on Dave.
Teach me to look at the first M7040 specs I look at!
Your right a M7040HXXX does not have a clutch disk.

......Dave..... Your M7040HXXX doesn't have a multi disk clutch!

NIW
Now I'm confused(not really) yes the M7040 has a multi-disk clutch in the hyd shuttle PLUS the damper clutch in the engine flywheel.

 

[North Idaho Wolfman]

I meant no multi disk dry (mechanical) clutch... Heck now I'm confused!
Still blaming it on Dave...
Dave, quick confusing me!

 

[100 td]

So the damper disk is a fixed drive spring damper to reduce shock loading and handle slight alignment tolerances, as a normal dry clutch would, without the added disconnection via friction pads?

 

[North Idaho Wolfman]

So the damper disk is a fixed drive spring damper to reduce shock loading and handle slight alignment tolerances, as a normal dry clutch would, without the added disconnection via friction pads?

Bingo...No not Dingo...

In other words yep you've got it right!

 

[greenacresnorth]

all clutching is done in the fwd/rev clutch pack, your modulator valve controls the clutch pack opening and closing depending on inching pedal and shifter position. some older power shift tractor had a dry clutch on the fly wheel (my 1970 JD4020 had one with a had lever) for cold starts but once engine was running the trans was turning 100% of the time.

 

[greenacresnorth]

you really want to see something fun, look at the logic and modulation valve on a Kubota glide shift trans, its a power reverser with a pull power shift dog syncro trans with 2 input ranges and a tail shaft spliter!!!! its a 4x2x2 to make 16 speeds.

 

[Tx Jim]

some older power shift tractor had a dry clutch on the fly wheel (my 1970 JD4020 had one with a had lever) for cold starts but once engine was running the trans was turning 100% of the time.

Back when employed by a JD dealer I remember making a service call on 4020 PS that wouldn't move under it's own power just to determine that someone had disengaged the damper clutch & didn't realize one needed to pull knob on the dash to engage the damper clutch.

 

[greenacresnorth]

Back when employed by a JD dealer I remember making a service call on 4020 PS that wouldn't move under it's own power just to determine that someone had disengaged the damper clutch & didn't realize one needed to pull knob on the dash to engage the damper clutch.

mine had a decent sized lever on the left side of the dash, it was spring loaded so you couldnt mess that up.... mine was a 1970 later model, not sure what the older non side console machines where like.

 

[100 td]

Bingo...No not Dingo...
In other words yep you've got it right!

I guess I should have read the whole thread, not just your last couple of comments, wouldn't have needed to ask. My bad eh!