Calibrating gearboxes?

[Flat 10]

This is mentioned on here sometimes, generically what is happening? I see various complicated instructions on how to do it for various models but why do you need to? Smoother shifts? And if it is something you need to do every few thousand hours why aren't there instructions in the hand book? (or are there and I'm looking in the wrong place?). Is it all to do with clutch pack fill times or is it different in different tractors? Is it just very modern tractors or slightly older ones too? Just curious really. TIA.
@Cowabunga you are good at explaining things.

 

[Curt]

If you drove a New Holland power command you'd understand! Good tractors but Christ the gear changes can get rough if not calibrated every now and again, used to have a Tm190 that left black marks on concrete changing from 12th - 13th!
Would also imagine rough gear changes decrease the life of a gearbox and all surrounding components, not just the comfort side of things!

 

[Brisel]

CNH has always been good at providing good instructions on how to do this,though it needs doing regularly on their machines.

My JDs need doing occasionally, even the auto power CVT ones, though the 8R does this itself automatically..

 

[Richard Devon]

Clutch plates wear so the combined pack thickness will gradually reduce meaning the pistons will have to travel further in order to lock the packs up and still maintain an acceptable shift time.
Small leaks will occur in the system which will need compensating for.
Oil quality will deteriorate over time affecting its viscosity - its good idea to recalibrate after changing oil
Shift solenoid spools will wear as time goes on making them freer and therefore quicker to react.

Basically by calibrating you're setting the optimum performance for the system at a given period of wear, oil quality and temperature all of which change

You'd have thought by now they would have software designed so they self-calibrated

 

[Brisel]

That would do the dealers out of easy work...

 

[Flat 10]

So any box with a few powershift steps like on early maxxums, ford sles, JD powerquads, don't know masseys dynashift(?) etc that are 15 or so years old could/should be calibrated? Or if they work fine leave well alone? I wonder how many have ever been done in their lives.

 

[Flat 10]

Clutch plates wear so the combined pack thickness will gradually reduce meaning the pistons will have to travel further in order to lock the packs up and still maintain an acceptable shift time.
Small leaks will occur in the system which will need compensating for.
Oil quality will deteriorate over time affecting its viscosity - its good idea to recalibrate after changing oil
Shift solenoid spools will wear as time goes on making them freer and therefore quicker to react.

Basically by calibrating you're setting the optimum performance for the system at a given period of wear, oil quality and temperature all of which change

You'd have thought by now they would have software designed so they self-calibrated

Very clear thanks.

 

[John 1594]

Strange..........ive got a 4 speed powershift box and it only needs calibrating once, and thats when you fit it.....


progress i suppose

 

[Flat 10]

Strange..........ive got a 4 speed powershift box and it only needs calibrating once, and thats when you fit it.....


progress i suppose

When I saw you'd posted I had a bet with myself what you'd say........... And guess what I was right

 

[John 1594]

When I saw you'd posted I had a bet with myself what you'd say........... And guess what I was right

Im just soooooo predictable!!!!!

Right enough though....sequence valves and brake bands adjusted on final assy.....

at 5000hrs you might need to to tighten the brake bands a turn, thats about it

of course, put an idiot on it, and it wont make 3000hrs....

 

[Richard Devon]

So any box with a few powershift steps like on early maxxums, ford sles, JD powerquads, don't know masseys dynashift(?) etc that are 15 or so years old could/should be calibrated? Or if they work fine leave well alone? I wonder how many have ever been done in their lives.

i don't think that 3 or 4 packs in sequence are too much to worry about, its when you have more complex systems with multiple packs for ranges, high/low splits, speed packs and master clutches which work in sequences is when its a bit more fussy

 

[cosmagedon]

@Richard Devon explained it well. As a general rule I calibrate the gearbox every service, it only takes 15 mins. On a NH you press a few buttons and it does it all automatically, just sit back and listen to the radio Keep on top of them and they don't end up with rough gear changes that wear everything out!

 

[ridger]

One of my tractors wouldn't drive one day lately, calibrated it and it's ok since

 

[Curt]

@Richard Devon explained it well. As a general rule I calibrate the gearbox every service, it only takes 15 mins. On a NH you press a few buttons and it does it all automatically, just sit back and listen to the radio Keep on top of them and they don't end up with rough gear changes that wear everything out!

It's a dealer job on anything after TMs now isn't it?

 

[nelson]

No they tell you in operators book for the for the t6050 6070 6080 6090 but they stop putting it in the t7 but it's the same. Our local jd dealer wanted 150 pounds to calibrate our jd so we didn't bother

 

[Gapples]

So any box with a few powershift steps like on early maxxums, ford sles, JD powerquads, don't know masseys dynashift(?) etc that are 15 or so years old could/should be calibrated? Or if they work fine leave well alone? I wonder how many have ever been done in their lives.

I'm not sure about other makes but Maxxums cannot be calibrated & don't need it anyway.
They either work fine or have a problem, on the power shift there is a pressure switch on each clutch pack. The p/shift control module obviously monitors these pressures & cuts drive if all is not as it should be. Basically when you shift from one gear to another the module does not begin to engage the next pack until the pressure in the first pack has decayed below a preset pressure, once this pressure is reached it opens the solonoid to the next pack selected, this overlap is constant regardless of oil temp or viscosity ensuring smooth changes.

The forward/reverse worked differently with no module, its uses modulation spools & a little gizmo called a wax stat ( certainly on the older models up to s/n 30000. )
This wax stat is attached to a spool with holes in it which gradually decrease in size, as the oil warms up the wax expands & pushes the spool out exposing smaller holes thus controlling oil flow to the packs.

 

[milkloss]

I'm not sure about other makes but Maxxums cannot be calibrated & don't need it anyway.
They either work fine or have a problem, on the power shift there is a pressure switch on each clutch pack. The p/shift control module obviously monitors these pressures & cuts drive if all is not as it should be. Basically when you shift from one gear to another the module does not begin to engage the next pack until the pressure in the first pack has decayed below a preset pressure, once this pressure is reached it opens the solonoid to the next pack selected, this overlap is constant regardless of oil temp or viscosity ensuring smooth changes.

The forward/reverse worked differently with no module, its uses modulation spools & a little gizmo called a wax stat ( certainly on the older models up to s/n 30000. )
This wax stat is attached to a spool with holes in it which gradually decrease in size, as the oil warms up the wax expands & pushes the spool out exposing smaller holes thus controlling oil flow to the packs.

Interesting, our 5130 kicks like a mule when you use the powershift, very hard on the trailer linkage on the road. Are they all like that?

 

[Gapples]

Its probably wear in the packs, as although it can compensate for a lot it cannot do that for fill times in the on coming pack.
This will especially be noticeable under load, as the on coming pack will take just that bit longer to fill meaning they can thump in a bit when worn.
So in this instant yes, a posh newer ECU & calibration could help overcome it.
Out of interest does your 5130 have an accumulator on the power shift circuit ?

 

[Cowabunga]

The calibration instructions are in the handbook for my NH8360 Range Command but never in MF handbooks for some obscure reason.
It doesn't need doing often and the operation calibrates clutch fill times to give smooth changes without slipping too much, in order to provide the optimum compromise between comfort and component life.
Not only does it calibrate the above, but in common with many modern semi-powershifts today, it calibrates the timing of the robotised synchronised mechanical range changes and the clutch release sequence that goes with those gear changes.
In the case of the NH, it also calibrates the forward/reverse synchro-shuttle. With the MF this is calibrating the two main traction clutches, one for forward and one for reverse, where the NH only has the one traction clutch [plus the synchronisers].

My NH does a lot of shuttling and heavy load gear changing, being a loader and buckraking tractor mainly, but it also does a bit of road work. Today its fetching another 12 ton load [plus trailer] of silage from a satellite farm over some very hilly roads. Yet it only needs calibrating every 2000 hours or so in my experience, if that. Same goes for the MF Dyna4 I've got, which admittedly has an easier time of it. It has only been calibrated twice yet, so I'm not entirely sure how often it will need doing. Once was after the first year, where it bedded in no doubt, and the second was at a service at about 1600 hours. Its done about 3000 hours now and seems fine.

Not sure what JD do these days. Back when I had a PowerQuad it had no electronic control and no service calibration, but the latest probably do. Their new synchronised powershift, whatever its called, is an interesting one and I haven't heard much about its smoothness, calibration or reliability. No news is probably good news.

 

[milkloss]

Its probably wear in the packs, as although it can compensate for a lot it cannot do that for fill times in the on coming pack.
This will especially be noticeable under load, as the on coming pack will take just that bit longer to fill meaning they can thump in a bit when worn.
So in this instant yes, a posh newer ECU & calibration could help overcome it.
Out of interest does your 5130 have an accumulator on the power shift circuit ?

To be honest I wouldnt know, will have a look when I get the chance.