Shear Bolts

[Turbo]

Incidentally, I once knew a bloke who welded up the coupling on a topper when he got tired of breaking shear pins. I think he did about £6000 of damage to both machines that afternoon..

Someone I know was continually breaking shear bolts in a topper buy abusing it so he upgraded them to grade 10 or 12 bolts!

After a few more broken bolts the gearbox cried enough and major damage occurred. The topper was scrapped as the cost of a new gearbox and the poor condition of the rest of the topper meant it wasn't worth fixing.

It was one of the cheap ones with a single large blade and they are a poor design. The big blade puts a big shock load on the drivetrain, they are hard to drive with a small tractor plus they don't cut that well.

The ones with 2 or 3 blades are slightly more expensive but are a much better machine.

 

[Jack Ryan]

On the old fordson & others, if you are brush hogging, and need to stop forward motion (like to keep from going out into a road) if you just pushed the clutch
down, the PTO (still engaged) will flywheel and continue to move the tractor.
That big disc back there makes a very good flywheel.

https://www.teamtractor.com/blog/understanding-over-running-clutches--28040

This does not detract from my suggestion to ditch the shear pins for a PTO overload clutch (at the gearbox input shaft)
As changing shear pins get's old real fast.

Whilst I have driven old Fordson tractors, I have not driven one with a PTO Implement attached. So I have not experienced this effect which, I assume, only happens with a single clutch.

I have, however, depressed a dual clutch enough to stop the tractor and instead raced forward at a great rate of knots. A rotavator (rotary hoe) can be a great propulsion device.

Interesting thread. I learned a few things, for example, a slasher is called a topper in some parts.

Thanks

 

[Bouledogue]

Years ago, Grey Fergies also used to push you through the hedge, unless you added an aftermarket overrun clutch, as referenced by Fred.

Back to the OP, it might be worth getting the guys to drop the skids / lift the blades a bit until they get used to things. Much kinder to the machine.

And remember to tell them some PTO horror stories. You know the kind of thing: "they found his naked body wrapped around the PTO shaft three days later", "they heard his screams in the neighbouring county but were too late to save him". All that sort of stuff. You also need to give them the various towing and rollover talks at some point.

 

[addjunkie]

@addjunkie ,
Essentially all of the above
Whilst being an adorable couple (truly), he and his good
lady have left Paris to take up the good life here...
Bought themselves a very tired Fordson Dexta with a linkbox,
and, now, this new topper.
...and so their adventure begins.
I'll get a photo of the ensemble next time they get it out of
the barn.
Hence my question re the shear bolt. I'm happy to help out,
and am just seeking to pre-empt the rather predictable future
scenarios. Which, as we already know, will no doubt happen on
a Sunday afternoon, or a Bank Holiday
Their mechanical knowledge, and feeling, is as close to zero as
one could possibly get. I'm sure they have other qualities.
One example; whilst I was hooking the topper up to the Dexta for
them, I asked him if he had any grease for the pins. He replied yes,
went off and came back with a tin of WD40....
Explaing the gearbox of the Dexta to him did take a while.....

As someone who left the city to take up the good life Im inclined to agree all this tractor malarkey takes a fair bit of learning. Doing it for them wont teach them, they need to be guided to learn, and big repair bills normally facilitate learning fair quickly.
Ive learnt after a couple of old tractors, modern 4 wheel drive ones are far less grief, get stuck less often and dont need constant love and attention.

 

[frank horton]

In France I had a v early 3m wide topper with no clutch...
It used drivebelts to the outer blades.....
I just used standard M10 bolts....they sheared easy enough.....always had a handful in the cab.....
Most cheap toppers dont have a clutch....Norm only M8 bolts....again just use standard bolts they go before any damage to the gearbox....