Ford 7740 PTO

[Timbo]

'94 white roof, 7740, 8000hrs, on feeder wagon. So, suddenly PTO runs all the time no matter where the knob is placed.

- No yellow PTO light at in either position.
- Switch off - pto runs immediately engine is started and engine labours alittle - brake is engaged.
- Switch on - pto runs, brake is off.
- if engine stopped with switch on and restarted, pto runs and brake is engaged until switch is cycled off to on.
- no other electrical issues.
- If PTO is shifted to 1000rpm and engine taken over 1200rpm, 1000 lamp flashes for overspeed so dash knows PTO is engaged.

Am obviously being very careful not to burn out brake band.

Thoughts?

 

[Timbo]

》bump《

 

[7610 super q]

40 series way above my pay grade. Alternator putting out 14 volts ? Similar problems with mine which resulted in a large bill from the dealer for renewing brake bands and just about everything else.... ( under 4000 hours too ).
@forblue , @agrimax ?


Helpful thread on the old BFF on 40 series issues, also a 40 series FB page.

 

[Lincsman]

Check the yellow light bulb is actually ok to start with, it may then give you a clue of whats going on.

 

[Timbo]

Check the yellow light bulb is actually ok to start with, it may then give you a clue of whats going on.

Update- yellow lamp broken bulb, now comes on with switch, but symptoms still the same.

Which are the pto and brake solonoids on an SLDP? See if it still runs with them disconnected...

 

[agrimax]

Don't recall there being one for the brake but the PTO control module in my 8240 was a big(double width) relay in the fuse box. Coloured blue but have seen them black too! That was a SLE of course but I'd expect the SL to have it too.
Sounds more like the plates are welded together in the PTO pack or at least badly warped.

 

[Lincsman]

So switch wise and dash display everything is working correctly?

 

[Timbo]

So switch wise and dash display everything is working correctly?

Yes.


Ill disconnect relay and also pto solonoid at back end n see if either stops the pto

 

[essexpete]

Yes.


Ill disconnect relay and also pto solonoid at back end n see if either stops the pto

If this happens then perhaps Agrimax is on the money.

 

[Timbo]

Update - back end coming apart to get the pack out....

 

[agrimax]

Cab up a couple of inches,minding the windscreen of course,and hyd lid off then...

 

[fermerboy]

The pto isn't that bad a job to get out. As said lift cab and put the bolts in above the axle mounts. Strip off all the spools and pipework etc. I used an engine hoist with a custom bracket to lift the hyd top off.

Once your there the rest isn't rocket science, my guess is cooked clutch plates.
Been a while but from memory ours started slipping driving the mixer wagon.

I managed to fix it myself so can't have been to hard.

 

[Timbo]

Should follow this up guys- so we pulled the lid, top shaft and pto pack out.

Release spring broken into 4 pieces and between the frictions n steels locking it solid. Frictions were about half warn. Replaced the lot from local dealer and good to go.
Pleasantly surprised the parts were not out of the way £

 

[Treemover]

Parts often are not the cost, its the labour getting in and out and fitting.

 

[Treemover]

You should have taken a few photos of the process to help other like myself have a go!