New Holland harsh PTO engagement

ColinV6

Member
Having a bit of an issue on my tractor.

Start of the day, PTO is super smooth and gentle to engage. However it gets progressively worse each load until it starts coming in with a bang and takes shear bolts. Tech said try calibration failing that it’s a new solenoid...

Anyone else had similar?
 

Fraserb

Member
Location
Scottish Borders
Having a bit of an issue on my tractor.

Start of the day, PTO is super smooth and gentle to engage. However it gets progressively worse each load until it starts coming in with a bang and takes shear bolts. Tech said try calibration failing that it’s a new solenoid...

Anyone else had similar?
We've had a couple like that, get them to calibrate it once its properly up to temperature and with whatever machine thats giving the problem on the back, apparently the load on the pto makes a difference when calibrating, no idea if thats right or not but it cured our 2.
 

cosmagedon

Member
Location
North Wales
Having a bit of an issue on my tractor.

Start of the day, PTO is super smooth and gentle to engage. However it gets progressively worse each load until it starts coming in with a bang and takes shear bolts. Tech said try calibration failing that it’s a new solenoid...

Anyone else had similar?
Yours is a small wheel base if I remember correctly so it's likely to be different to the longer wheel base problems we had.

On a long wheel base it auto calibrates everytime you start the PTO and there's no actual calibration procedure for it, this is the soft start. It was ok cold but when hot it would twist a PTO like chocolate or snap a shear bolt. We could sort it by deleting the calibration settings in the H menu then it would be ok for a short while.

The fix in this instance was a new PTO solenoid, delete the calibration settings and it's been good ever since.
 

ColinV6

Member
We've had a couple like that, get them to calibrate it once its properly up to temperature and with whatever machine thats giving the problem on the back, apparently the load on the pto makes a difference when calibrating, no idea if thats right or not but it cured our 2.
He said to run a gearbox calibration which I did after it had been working a good 5 hours so was plenty warm enough, I actually did this about 2 weeks ago so don’t hold much hopes for this fix.
Told him I’d see if it does the same tomorrow again on muck, and phone him back...
 

ColinV6

Member
Yours is a small wheel base if I remember correctly so it's likely to be different to the longer wheel base problems we had.

On a long wheel base it auto calibrates everytime you start the PTO and there's no actual calibration procedure for it, this is the soft start. It was ok cold but when hot it would twist a PTO like chocolate or snap a shear bolt. We could sort it by deleting the calibration settings in the H menu then it would be ok for a short while.

The fix in this instance was a new PTO solenoid, delete the calibration settings and it's been good ever since.
That sounds very similar, first few loads it’s super smooth, this changes to a small jerk on start up, and ends up with a very noticeable bang, like a shock load. After 2 or 3 loads of muck the PTO shearbolt goes.
If you stop the tractor, even just long enough to change a shearbolt, it’s back to being nice and smooth for a few loads again.
I wouldn’t be surprised if he’s out tomorrow to fit a new solenoid. I dread to think of the price?!
 

cosmagedon

Member
Location
North Wales
That sounds very similar, first few loads it’s super smooth, this changes to a small jerk on start up, and ends up with a very noticeable bang, like a shock load. After 2 or 3 loads of muck the PTO shearbolt goes.
If you stop the tractor, even just long enough to change a shearbolt, it’s back to being nice and smooth for a few loads again.
I wouldn’t be surprised if he’s out tomorrow to fit a new solenoid. I dread to think of the price?!
Once ours was up to temp it was rough all day then.

Solenoids are about £100 and can be easy to fit if the bolts come off easy, only 2 Allen bolts but I've seen them rounded on the past and then you start swearing.
 
That sounds very similar, first few loads it’s super smooth, this changes to a small jerk on start up, and ends up with a very noticeable bang, like a shock load. After 2 or 3 loads of muck the PTO shearbolt goes.
If you stop the tractor, even just long enough to change a shearbolt, it’s back to being nice and smooth for a few loads again.
I wouldn’t be surprised if he’s out tomorrow to fit a new solenoid. I dread to think of the price?!
Sure it was less than £100 when we changed one last year easy enough job just fiddle with lack of space to do just make sure its clean around the solenoids and you clean the heads out of Allen bolts before trying to undo them as it's a pig of job if they get rounded off
 

Jato

Member
Once had one which would change its own calibration figures in the controller. Symptoms were very similar.
You could calibrate it and it could be ok for the day, or sometimes only an hour.
Recalibrate it and ok and then good again until it changed settings.

NH could not resolve it or understand it, but they did have a modified PTO clutch with additional springs in which somehow dampened the engagement. (almost a mechanical soft start function).

This was fitted and it did cure the harsh engagement

The actual cause was never found, tractor was maybe 1000 hours on when problem started.

Can’t remember if which model, think it was either T6.175 or T6070.

Also know of a T7030 where the bolts fastening the PTO tone wheel came loose.
this is where pto load is measuring twist from flywheel to operate power boost
 
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138: Special episode: Covid-19 impact on the Potato sector

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138: Special episode: Covid-19 impact on the Potato sector

Written by AHDB

In this special issue of the Potatoes Podcast we will discuss the impact of Coronavirus on the Potato Markets. A fresh update on how Covid-19 has resulted in an increased demand on the retail market, while the chipping market has suffered the hardest hit. The uncertainty of the current situation will force businesses to...
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