Fendt/MF/AGCO cvt transmission...

[Cowabunga]

Over silage time my MF7490 has developed a transmission drag when the shuttle lever is in neutral. This also seems to inhibit range changes, but there is no drag when the clutch pedal is pressed. There is considerable drag when the shuttle is put in neutral from reverse.

At first I thought that the Bowden cable that links the emergency transmission manual control on the right top cover with the actuator on the left, in front of the rear axle, had gone stiff or seized. However, after detaching the cable at both ends and checking, the cable is fine and full travel is possible with no resistance.

Anyone had this issue with either Fendt or MF? Is there a calibration possible?

Hope it doesn't turn out to be expensive. Only last week, within four loads of each other, I firstly had the exhaust lower bend fail, and then a trailer came off and the drawbar punched a great big long rip in the inner sidewall of a 70% good Michelin 620/70R38. No idea how much the new bend cost, but the tyre cost me £1090 + VAT for a new BKT.

 

[mtx.jag]

@Spud

 

[Spud]

Under the time guard at the axle end there is a little potentiometer with a plastic arm. Check that all is ok in that area - no cracks in the plastic, or build up of debris that might inhibit movement.

Where is the shuttle sharpness set? If you're used to it's behavior set at say 3 or 4, and someone has adjusted it to 1, you may see the symptoms you describe.

 

[Cowabunga]

Under the time guard at the axle end there is a little potentiometer with a plastic arm. Check that all is ok in that area - no cracks in the plastic, or build up of debris that might inhibit movement.

Where is the shuttle sharpness set? If you're used to it's behavior set at say 3 or 4, and someone has adjusted it to 1, you may see the symptoms you describe.

Took the guard off the potentiometer and cleared the debris out at the same time as we tested the Bowden cable. All seems OK. Not sure about cracks in the plastic of the pot though, as it's awfully dark and cramped down there. Shuttle sharpness is still set at 3. No, this is quite different and there is a definite lack of neutrality in neutral. Until a few weeks ago shifting the shuttle to neutral had the same effect as pressing the clutch pedal, a feeling of complete drive disconnect.

Another symptom it has is that occasionally it now loses the turbo clutch effect. I came to a junction the other day, a 'Give Way' and stopped by use of the brakes only. The engine actually stalled. First time its ever done that.

I'm hoping that either there's a calibration issue or that it could be that potentiometer. No fault codes though except a long established T4070 or something like that, which comes after the transmission has warmed up and lit the orange dash light. That is to do with the transmission filter bypassing but it is usually the sensor failing. It has had new filters and sensor in the past but continues with that fault, which nobody can solve apart from suggesting that I fit another new sensor.

 

[Spud]

Took the guard off the potentiometer and cleared the debris out at the same time as we tested the Bowden cable. All seems OK. Not sure about cracks in the plastic of the pot though, as it's awfully dark and cramped down there. Shuttle sharpness is still set at 3. No, this is quite different and there is a definite lack of neutrality in neutral. Until a few weeks ago shifting the shuttle to neutral had the same effect as pressing the clutch pedal, a feeling of complete drive disconnect.

Another symptom it has is that occasionally it now loses the turbo clutch effect. I came to a junction the other day, a 'Give Way' and stopped by use of the brakes only. The engine actually stalled. First time its ever done that.

I'm hoping that either there's a calibration issue or that it could be that potentiometer. No fault codes though except a long established T4070 or something like that, which comes after the transmission has warmed up and lit the orange dash light. That is to do with the transmission filter bypassing but it is usually the sensor failing. It has had new filters and sensor in the past but continues with that fault, which nobody can solve apart from suggesting that I fit another new sensor.

It sounds obvious, but check the plug on said potentiometer too - I've had them come slack before. Does altering the sharpness setting alter its behaviour as it should? (ie is it an electrical fault?)

How old is it? Many hours? iirc you've had it a good while, may be a tier 2? I had odd happenings at about 7000hrs on my 7480, and 5000 on the 7495 - the culprit in both cases was wiring. Pull some of the ridged plastic conduit off the gearbox wires and have a good look - I'll wager it has ridges in the insulation on the wires - somewhere there will be a break, but there'll also be lots of weak areas too. iirc a gearbox loom is iro £400 + fitting. Neither tractor had a problem after that.

A couple of things to be aware of:

A gearbox loom is much cheaper than a new gearbox.
An over ambitios service manager condemned the gearbox on my 7495 - eventually he relented to my protestations, and thos of his mechanic, and ordered a loom. Which was wrong when it arrived. Another was ordered, which was the wrong loom but in the right bag. Third time lucky. Check compatibility before fitting is the key here.

Just as an aside - check the smell of the transmission oil, and the level of the oil in the trumpet housings. I recently bought a 2005 7490 with high hours - it has a leak from one trumpet into the gearbox - which put the transmission filter light on - slightly thicker oil would probably also cause the drag to which you refer.

Bloody good tractors imo, sure it'll be summat simple.

 

[Dbs]

I’ve had this with a 7480 when the shuttle lever was in neutral the tractor would slowly creep, did a gearbox calibration and all was fine again.

 

[Treemover]

Before my vario failed, it did the same creeping. I also changed the potentiometer but that did cure a problem the failed unit was causing. Also changed filters and sensors; but in the end the transmission gave up.
Mine also leaked into trumpet housing, I remember having to suck out the oil. I hope yours doesn’t fail.

 

[Spud]

Before my vario failed, it did the same creeping. I also changed the potentiometer but that did cure a problem the failed unit was causing. Also changed filters and sensors; but in the end the transmission gave up.
Mine also leaked into trumpet housing, I remember having to suck out the oil. I hope yours doesn’t fail.

Mine is leaking gear oil from the trumpet, into the transmission, not the other way around. Mercifully all is functioning fine.

When you say your transmission gave up, how? What happened?
Did you check the wiring?

 

[2wheels]

It's knackered, £7500 to sort. Just my opinion .what happened to my emogi?

 

[djiedjie]

Both our 7619's had the same. Turned out to be the potentiometer, after the mechanic changed it en calibrated the transmission both are fine again now.

 

[Pheasant Surprise]

It's knackered, £7500 to sort. Just my opinion .what happened to my emogi?

You’ve been stripped of it, until you start posting sensible suggestions

 

[2wheels]

You’ve been stripped of it, until you start posting sensible suggestions

who knows, although it was said very much tongue in cheek it may just possibly though unlikely turn out to be correct.

 

[Pheasant Surprise]

who knows, although it was said very much tongue in cheek it may just possibly though unlikely turn out to be correct.

Let's hope it doesn't come to that. Can you imagine the duck going to the MF dark side (dark place?). The consequences are unimaginable

 

[Cowabunga]

It sounds obvious, but check the plug on said potentiometer too - I've had them come slack before. Does altering the sharpness setting alter its behaviour as it should? (ie is it an electrical fault?)

How old is it? Many hours? iirc you've had it a good while, may be a tier 2? I had odd happenings at about 7000hrs on my 7480, and 5000 on the 7495 - the culprit in both cases was wiring. Pull some of the ridged plastic conduit off the gearbox wires and have a good look - I'll wager it has ridges in the insulation on the wires - somewhere there will be a break, but there'll also be lots of weak areas too. iirc a gearbox loom is iro £400 + fitting. Neither tractor had a problem after that.

A couple of things to be aware of:

A gearbox loom is much cheaper than a new gearbox.
An over ambitios service manager condemned the gearbox on my 7495 - eventually he relented to my protestations, and thos of his mechanic, and ordered a loom. Which was wrong when it arrived. Another was ordered, which was the wrong loom but in the right bag. Third time lucky. Check compatibility before fitting is the key here.

Just as an aside - check the smell of the transmission oil, and the level of the oil in the trumpet housings. I recently bought a 2005 7490 with high hours - it has a leak from one trumpet into the gearbox - which put the transmission filter light on - slightly thicker oil would probably also cause the drag to which you refer.

Bloody good tractors imo, sure it'll be summat simple.

Good points. Thanks.
Took the pot plug off to get better access to the Bowden cable anchor pin, and reinstalled. Nothing appeared to be amiss.
Yes, mine has a leak in the hubs, slightly worse in one side than the other. This lets EP90 reduction gear oil into the transmission. Common issue which I know about and there are modified seals to fit if ever I take the trumpets off for some reason.
I don't think it is appreciably thicker oil that causes the light to come on, because it made no difference when I changed the oil last time.
It is not due another oil change again officially, but I change it more often than specified anyhow and I was aiming to change oil and filters after harvest anyway, so we'll see how that goes. However, the drag has come on quite suddenly in the last 50 hours and it has had some hard work mowing and transport during that time, which should have heated the oil up nicely. The light and fault code have been occurring for years.

It is a 2004 build. Only just over 5000 hours. Ended contract silage making about ten years+ ago so hours are not high but they are quite hard hours, mainly on slurry tanker.

Which transmission oil do you think I should use? The new MF super universal 10W/40 recommendation or the old recommendation of the 10W/30 super universal or UTTO?

 

[Cowabunga]

I’ve had this with a 7480 when the shuttle lever was in neutral the tractor would slowly creep, did a gearbox calibration and all was fine again.

Is that a driver capable operation or does it need a man with van and laptop?

 

[Spud]

Good points. Thanks.
Took the pot plug off to get better access to the Bowden cable anchor pin, and reinstalled. Nothing appeared to be amiss.
Yes, mine has a leak in the hubs, slightly worse in one side than the other. This lets EP90 reduction gear oil into the transmission. Common issue which I know about and there are modified seals to fit if ever I take the trumpets off for some reason.
I don't think it is appreciably thicker oil that causes the light to come on, because it made no difference when I changed the oil last time.
It is not due another oil change again officially, but I change it more often than specified anyhow and I was aiming to change oil and filters after harvest anyway, so we'll see how that goes. However, the drag has come on quite suddenly in the last 50 hours and it has had some hard work mowing and transport during that time, which should have heated the oil up nicely. The light and fault code have been occurring for years.

It is a 2004 build. Only just over 5000 hours. Ended contract silage making about ten years+ ago so hours are not high but they are quite hard hours, mainly on slurry tanker.

Which transmission oil do you think I should use? The new MF super universal 10W/40 recommendation or the old recommendation of the 10W/30 super universal or UTTO?

I use a generic version of MF's Power HC plus, which I think is 10w30 (bought from agco dealer and used on everything from the youngest to the oldest.

85w140 in the trumpets slows the leak.

2004 is an early one - I've just bought a 2005 7490 with 10000 hrs as an extra tractor, likely same model as yours

 

[Drillman]

Good points. Thanks.
Took the pot plug off to get better access to the Bowden cable anchor pin, and reinstalled. Nothing appeared to be amiss.
Yes, mine has a leak in the hubs, slightly worse in one side than the other. This lets EP90 reduction gear oil into the transmission. Common issue which I know about and there are modified seals to fit if ever I take the trumpets off for some reason.
I don't think it is appreciably thicker oil that causes the light to come on, because it made no difference when I changed the oil last time.
It is not due another oil change again officially, but I change it more often than specified anyhow and I was aiming to change oil and filters after harvest anyway, so we'll see how that goes. However, the drag has come on quite suddenly in the last 50 hours and it has had some hard work mowing and transport during that time, which should have heated the oil up nicely. The light and fault code have been occurring for years.

It is a 2004 build. Only just over 5000 hours. Ended contract silage making about ten years+ ago so hours are not high but they are quite hard hours, mainly on slurry tanker.

Which transmission oil do you think I should use? The new MF super universal 10W/40 recommendation or the old recommendation of the 10W/30 super universal or UTTO?

Hold on a cotton quacking moment......


The Duck is asking advise about oil spec!


Has his account been hacked by an imposter?

 

[Dbs]

Is that a driver capable operation or does it need a man with van and laptop?

I did it myself I’ll have a look for the instructions how to do it, just can’t remember off the top of my head.

 

[Treemover]

Mine is leaking gear oil from the trumpet, into the transmission, not the other way around. Mercifully all is functioning fine.

When you say your transmission gave up, how? What happened?
Did you check the wiring?

It was a few years ago, so can’t remember exact details; but the vario failed on the road on a dangerous bend.

All sorts of codes came up. Went to dealer and reman vario went into it. Was never told what went wrong. I was a bit bitter at the time.

Seeing what’s happening to other semi power shift tractors; vario replacement costs are quite reasonable; but if they have the same degree of reliability or lifespan is another argument.

Fendt told me that if the vario saved a liter of fuel per hour over a power shift the vario was justified. I can see their point. Efficiency, productivity sure, but costs to run and reliability are important too.

 

[Cowabunga]

It was a few years ago, so can’t remember exact details; but the vario failed on the road on a dangerous bend.

All sorts of codes came up. Went to dealer and reman vario went into it. Was never told what went wrong. I was a bit bitter at the time.

Seeing what’s happening to other semi power shift tractors; vario replacement costs are quite reasonable; but if they have the same degree of reliability or lifespan is another argument.

Fendt told me that if the vario saved a liter of fuel per hour over a power shift the vario was justified. I can see their point. Efficiency, productivity sure, but costs to run and reliability are important too.

Yes but you bought yours with over 10,000 hours on the clock, didn't you?