Ford 7740 SLE Problems

[NH-James]

Hi all, new to this forum and to farming so bear with me!
Got a 7740 SLE here with the 16x16 powershift transmission which has become more and more tetchy of late. The low hydraulic pressure light is on and apparently has been for years without a problem. The farmer has known about a problem with the PTO clutch for a while where the clutch is constantly disengaged (with the engine running can't get it in to 540 or 1000 without horrible noises!), PTO kicks in violently but once it's in, it works fine and turns off on the switch. I'm guessing the clutch relies on hydraulic pressure to work properly? Another supposedly unrelated (but I believe related) problem is having to calibrate the clutch packs. It used to need calibrating if left unused for a few days, now it needs calibrating every time it is used and often refuses to calibrate if warm. A variety of fault codes come up - E24, E28 and E32, a different one every time. There is no drive forward or reverse when these come up, must be calibrated to move it. Calibrate it when first started up and you can often complete a steady job like mowing, problems start when you drop the engine revs too low or (god forbid) turn it off! Once it loses drive and an error comes up, you cannot move it for a few hours until it has cooled down, then it will allow you to calibrate the clutch packs. When calibrating, numbers on the dash climb from about 30 and are supposed to stop from 120 -180, this keeps going to well over 210 before it stops, is the number any kind of indicator on wear? Others say that theirs work fine at 200 or more, but I think it could be a clue. Thirdly, I believe the rear lift capacity is poor (makes sense with the low pressure light on the dashboard) and from what I gather, all 3 systems use the same pump? Obviously if it's a pressure problem, it's not going to get better when it's warm due to the lower viscosity of the oil. Power steering is fine, does this use a separate pump? So what would be a good start to the investigation? I'm going to change the filters but they are no where near due replacement yet. Could there be an internal leak? Valves anywhere? Obviously worst case would be pump replacement at £2000! Or does anyone think they're unrelated problems with worn clutch packs maybe? Finally, does the tractor have a conventional clutch on the back of the engine? I have very little experience with tractors so may be overlooking something simple but have reasonable mechanical knowledge so would like to think I can solve this with some help!

Thanks - James

 

[multi power]

i new pump used to be £1845, list price but can be got for about 1k
i would test the pressure
there could be an internal leak, my 8340 had
there is no conventional clutch

 

[NH-James]

Forgive me but where do I test the pressure from? Unscrew the pressure sender? Must get a workshop manual as I don't even know where the sender is located! What problems did the internal leak cause for you?

 

[NH-James]

Can anyone confirm whether the PTO clutch is hydraulic or not? I know it has wires going to a solenoid but does the solenoid control flow of oil? Some people have told me there is no hydraulic control there whatsoever, so don't want to be barking up the wrong tree thinking it's related to the rest of the problems!

 

[Kevtherev]

Pto is hydraulic engaged wet clutch pack.
@ploughman1963 is the man to ask

 

[Badshot]

There is a gasket that causes the low pressure light to come on, it was done to most of the sle fords locally, quite a few with cornflake boxes. All I can tell you is it is on the right side and can be done with little hassle, dismantling. It makes the gear change jerky at first, I dare say if it is well and truly buggered it could cause some of the issues you describe.

 

[Nearly]

Buy one! http://www.ebay.co.uk/itm/Ford-Trac...K_BOI_FarmingEquipment_RL&hash=item19f23ef671

First check the hydraulic switches around the pump (inside the right rear wheel) have a friend in the cab and see when they come on or go off.
My 83 had the same light.
Just changed the o ring on the pto end of the first hydraulic pipe. Hyd pump off, pipe goes from outlet of hyd pump up inside the back end to the PTO pack. It can cause your issues, as all oil goes to the PTO pack first then onwards.

Good luck.

 

[blackbob]

There is a gasket that causes the low pressure light to come on, it was done to most of the sle fords locally, quite a few with cornflake boxes. All I can tell you is it is on the right side and can be done with little hassle, dismantling. It makes the gear change jerky at first, I dare say if it is well and truly buggered it could cause some of the issues you describe.

Yes I had the dealer do that on mine, I asked the service manager chap why the red light was coming on and he said it was a known fault, don't think it cost much. This maybe 12 years ago? He did say it needed sorting asap because the low pressure would do damage.

 

[multi power]

Forgive me but where do I test the pressure from? Unscrew the pressure sender? Must get a workshop manual as I don't even know where the sender is located! What problems did the internal leak cause for you?

i expect there is a few places where you can test it, this should hepl to confirm where any leakage is
my tractor lost transmission, spools n pto, only steering stil worked, it was just a blown seal/ o ring somewhere, shame they only found it after fitting a new pump



i very simply solved all 40series problems,


i bought the tractor in my avator

 

[multi power]

Buy one! http://www.ebay.co.uk/itm/Ford-Trac...K_BOI_FarmingEquipment_RL&hash=item19f23ef671

First check the hydraulic switches around the pump (inside the right rear wheel) have a friend in the cab and see when they come on or go off.
My 83 had the same light.
Just changed the o ring on the pto end of the first hydraulic pipe. Hyd pump off, pipe goes from outlet of hyd pump up inside the back end to the PTO pack. It can cause your issues, as all oil goes to the PTO pack first then onwards.

Good luck.

that sounds like what happened my 8340, the workshop foreman said something about it being a problem with pto pipe, but the numpty who came out never spotted it

 

[wdah/him]

our 7740 sle stopped dead on road, o ring in pto, about four hours work and all sorted, i didnt do it, pump off and just be persistant as its fidly. gear change3 was very jerky and calibrated to over 210 in 2nd and 5th, this was solenoid trouble, cleaned and no real change, new sorted it out well, only 130 each, is it jerky in some or all gears? if some most likely solenoids. i also have one senser for low oil pressure disconnected but the other still works, must replace it.

 

[NH-James]

Thanks for all the ideas guys, at least I've got something to go off now, fingers crossed it'll get sorted! Too busy at the moment but gives me something to do this winter! wdah/him: not jerky in any gears now as it's calibrated every time it's used, but I think it used to be jerky in some gears.

 

[Two Tone]

Just done an interesting fix on our Ford 7740 (SLE) which was having starting problems. It is just coming up to 10,000 hrs

Over the last 3 months, it had developed a habit of not starting from cold unless you jiggled the forward/start/reverse gear lever. Once the tractor had warmed up, it would start no trouble at all. However, just occasionally, once started, it wouldn't move, unless you stopped and restarted it again.

But as of last Monday, the tractor would not start at all, no matter how much you jiggled the forward/start/reverse gear lever.

So firstly, I renewed the relay on the firewall above the starter motor. But the tractor still refused to start. I could start the tractor by shorting the starter solenoid to the +ve HT power lead. This proved that the starter was still working OK.

I located the safe starter switch on top of the gearbox, just in front of the forward/start/reverse input shaft. I pulled the 2 wires off and shorted them. Bingo the tractor started! However it wouldn't move. BUT once started, removed the short (tractor started) it would move. This proves that the safety switch not only allows safe starting in neutral, but that it won't allow forward or reverse movement unless the switch tells the gearbox that it is no longer in neutral.

Thinking it must be a faulty safety switch, I ordered and fitted a new one but it still wouldn't start! I Then connected the old switch to the wire and pressed the ball in manually and it started. This proved the old switch was not faulty. Rather, it was the rail that operates the switch that had worn.

Solution - rather than fit a new or less worn forward/start/reverse rail (Christ knows how much that would cost!!), put the old switch into a lathe and skim back the neck about 0.25 mm so that the switch screws into the gearbox about 1/4 of a turn more, which makes the ball on to end of the switch fit against the rail enough to start and allow the tractor to move.

Simples!!

 

[John 1594]

i expect there is a few places where you can test it, this should hepl to confirm where any leakage is
my tractor lost transmission, spools n pto, only steering stil worked, it was just a blown seal/ o ring somewhere, shame they only found it after fitting a new pump



i very simply solved all 40series problems,


i bought the tractor in my avator

You do realise your avatar is still a headstone and a poppy

 

[Drillman]

You do realise your avatar is still a headstone and a poppy

Does that mean the mf has died and has been buried?

 

[Boohoo]

Does that mean the mf has died and has been buried?

By saying that it's died you're suggesting that it had some life in it to start with!

 

[Drillman]

By saying that it's died you're suggesting that it had some life in it to start with!

Ah yes very good point

 

[multi power]

Ha ha