The Fordson Tractor Pages Forum

after my last tractor road run my major has developed a bad vibration when under full throttle the wings and footplates vibrate real bad i thought it was a bearing gone bad in back end or gearbox but have now realised that she does it if i rev engine up at a stand still even does it when clutch is depressed so that must rule out gbox as the tractor is not moving and box is stationary there is no knocks or clunks from engine and she runs as sweat as a nut does anyone think that its a flywheel or pressure plate fault or does anyone think that its anything else thanks in advance

Hi Dave

You have done a logical fault diagnosis. With tractor stationary, it can't be rear axle related. With clutch depressed, assuming clutch disengages, it can't be anything in the gearbox. If your engine sounds well, it almost certainly is well - a mark 1 human ear is a pretty good diagnostic tool! It's unlikely to be anything to do with the flywheel - not much to go wrong there short of something catastrophic which you'd know about pdq.

That leaves the clutch. It's a wearable, replace in service item. My guess is that something has come adrift, throwing the flywheel out of balance. I may be completely wrong, of course!

Best

Adrian

Hi Dave
Does the tractor have live pto/hyds. Meaning 2 stage clutch . if it does it could be one or more of the pegs that holds the pressure springs together and attaches them to the clutch assembly has snapped the nut off the end.
This would then make the rotating mass of the flywheel out of balance .
My friends power major dumped a couple of these, and the clutch exploded in the bell housing while idling. The biggest part left intact was the flywheel the rest half filed a wheel barrow when they shoveled it all out .
If it is that and maybe more than one spring, you may notice the clutch feels a bit lighter to push with less spring pressure . it's not a fool proof tell tale though .
you may have to split the tractor to check the clutch to find it, if you do have the 2 stage and nothing else shows up bad . Ive never seen balance problems with a single stage unit. But doesn't mean a bolt or part could not fall off one of those either .
Regards Robert

Hi Dave.
Have you got the engine max RPM’s set with in the factory specs?
On a few of mine the top RPM’s are a little higher than they should be, normally when driving down the road everything seems fine but if I’m running down the back side of a hill they will pick up enough more speed to start vibrating rather badly, the harmonics will actually make the fenders “howl” quite loudly.

Pat

Slight vibration in Live Clutch.















I had one stop in the field whilst ploughing. The driver said he heard nothing but the largest piece left when I split the tractor was the centre spline of the clutch plate.

Most of the causes of engine vibration have been covered above. Over revving, loose flywheel or faults on a live clutch are the most likely. The live clutch weakness is why I would never advise putting it on a 6 cylinder conversion.

You could try removing the starter and checking if you can see something. The opening will be restricted but if you could get your hands on an inspection camera it would be useful.

If it is a standard clutch it may be something like loose/sheared bolts on the clutch itself or even a loose flywheel.

Crikey, Brian. Looks like it has been hit by a stray Exocet! I can hardly believe my eyes. The flywheel has, well, flown! If I'd been driving that tractor, I think I would have needed a slug of something medicinal from the Johnnie Walker range of remedies!

Best

Adrian

Thanks for all your replys its a single clutch model, think ill have to split her over the winter and see whats what she did 35 mile on sunday without fault other than the vibration as said