Bunny hopping when slashing.

[Collector]

Unfortunately I don’t think I can add a video.
Im being driven mad by the tractor bunny hopping/ surging many times when slashing. It gets so bad I have to stop the tractor then restart. It’s worse going down hills but even happens up hill lately.
So, hills, 4wd, 4 foot slasher, almost new tractor.
Never happened to me with other tractors going back 50 years.
Any thoughts ?

 

[85Hokie]

Welcome to the Forum,

Quick question - IF YOU are not slashing - does it do the same thing? Reason I ask, trying to see if this is an engine "problem" or pto problem.

Does this machine have overrunning clutch at the PTO?

 

[old and tired]

Create a youtube channel, free, upload the video there and copy and paste the video link back to this site.

Are the tires sizes correct and not binding up?

 

[tinkerwitheverything]

Take it out of 4 wheel drive and see if it does it. 4 wheel drive tractors have the front's turning a bit faster then the rears so there's always a spin /slipage happening when in 4x4 ..

 

[MINICUP28]

Is your throttle foot being jarred because of bumpy terrain? I have that problem mowing a poorly plowed field. I have to use cruise control at a slow pace to maintain an even speed, otherwise I'm surging in a feedback that gets so bad I have to stop.

 

[Trimley]

Put the 3PH in float?

 

[Collector]

Welcome to the Forum,

Quick question - IF YOU are not slashing - does it do the same thing? Reason I ask, trying to see if this is an engine "problem" or pto problem.

Does this machine have overrunning clutch at the PTO?

Good question . I don’t think so , but I’m off to slash in an hour , so I’ll test it.

 

[Collector]

Create a youtube channel, free, upload the video there and copy and paste the video link back to this site.

Are the tires sizes correct and not binding up?

Thanks for that. Tyres as from new, I can’t see them being wrong , but who knows ?

Is your throttle foot being jarred because of bumpy terrain? I have that problem mowing a poorly plowed field. I have to use cruise control at a slow pace to maintain an even speed, otherwise I'm surging in a feedback that gets so bad I have to stop.

No it’s not bumpy ground. I don’t think the tractor has cruise control, but it’s not my tractor . It’s hydrostatic drive. I have to keep my foot on the pedal. But I’m happy to be proved wrong !

 

[Collector]

Welcome to the Forum,

Quick question - IF YOU are not slashing - does it do the same thing? Reason I ask, trying to see if this is an engine "problem" or pto problem.

Does this machine have overrunning clutch at the PTO?

Just standard from factory pto set up.

 

[PoTreeBoy]

Does this machine have overrunning clutch at the PTO?

According to the parts diagram, the L3800H has the overrunning clutch.

 

[Grandad4]

No it’s not bumpy ground. I don’t think the tractor has cruise control, but it’s not my tractor . It’s hydrostatic drive. I have to keep my foot on the pedal. But I’m happy to be proved wrong !
[/QUOTE]

Is it a technique issue? How do you use the foot pedal?
A) Heel on the floor, push the pedal with your toe (like the gas pedal in your car/truck), or
B) Whole foot on the pedal, use your ankle to control speed and direction.
If you are using style B, it's really hard to control the pedal on rough ground. The other method is much more controllable, or at least I found it so.
If it bunny hops using the A style, I always figured it was time to slow down some.

 

[Trimley]

If it has means to set/lock throttle position, you might try it.

 

[GrizBota]

I’d try to isolate the situation that causes the bunny hopping. Normally you run with the PTO on 4WD. I’d try PTO on 2WD. PTO off 2WD. PTO off 4WD. Etc.

I agree the behavior is odd. It should not bunny hop.

 

[mikester]

Add more weights up front or take them all away

Change gears and ground speed

 

[NorthwoodsLife]

Take it out of 4 wheel drive and see if it does it. 4 wheel drive tractors have the front's turning a bit faster then the rears so there's always a spin /slipage happening when in 4x4 ..

Ah, Really? Not true.

Secondly:

Slasher? Sounds like a horror movie. You mean rotary cutter.

You are going too fast. Or the brush that you are cutting is too thick for your tractor at any speed. "Bunny Hopping", or jerking is due to having too heavy of a load on the machine.

 

[85Hokie]

Ah, Really? Not true.

Secondly:

Slasher? Sounds like a horror movie. You mean rotary cutter.

You are going too fast. Or the brush that you are cutting is too thick for your tractor at any speed. "Bunny Hopping", or jerking is due to having too heavy of a load on the machine.

NO- he IS correct, OEM front tires WILL pull the rears slightly, typically the fronts can spin about 2% faster than the overall ratio - notice on an older machine the fronts are usually worn much faster than the rears, the lead on the front does allow the tractor to turn better into corners.

AND, YES - he DOES mean a slasher, if you did not look, he is from down under - Australia, where there do use different term for different things. Slasher is a rotary cutter, that is correct.

 

[NorthwoodsLife]

NO- he IS correct, OEM front tires WILL pull the rears slightly, typically the fronts can spin about 2% faster than the overall ratio - notice on an older machine the fronts are usually worn much faster than the rears, the lead on the front does allow the tractor to turn better into corners.

AND, YES - he DOES mean a slasher, if you did not look, he is from down under - Australia, where there do use different term for different things. Slasher is a rotary cutter, that is correct.

I apologize.

RE: The slasher definition was my mistake. I apologize for my not checking that the OP was from Australia. Australia is a very different English place. Being an old school American boy here, is my only excuse. Sorry.

RE: Front tire ratio, I will not dispute deeply, because I don't care to. That being said, engineers generally don't design in a 2% difference because that is miniscule with rubber tires. So I don't believe they engineer a 2% faster, factor. We'd have to talk to the Japanese engineers. But it's not going to cause "bunny hopping". An Aussie term too, I suppose. My mistake. IF the front tires wear out faster it's because they constantly side slide in turns, and they carry more weight in a loader use environment. (edit: no brainer... the fronts are smaller and make more revolutions than the rear. ) In fact, if the fronts wear out faster, your 2% just became a negative number in a few hours by your explanation. (edit: So, you're wrong. But I apologize anyway, because 85Hokie is a Moderator and on Staff).

I'll stop replying to foreigners. Foreigners to me, that is.

My apologies. Carry on.

 

[GrizBota]

Goodbye?

 

[NorthwoodsLife]

There are some asshats on here.

 

[NorthwoodsLife]

Goodbye?

Good idea