Bent mower shaft

Powerfab

Powerfab

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#1
Ok,

This is well off topic, but hey it's for a commercial grade mower.

I've a Yanmar diesel ride on mower with a shaft drive to the deck. At some time under previous ownership one of the deck pulleys exploded and ripped apart the deck mount. This has all been rebuilt but its clear that when it went ballistic something bent the drive shaft. It's not enough to wreck anything in itself, but it sets up a vibration at full chatter that will eventually create excessive backlash in the gearbox and cause premature failure. Plus it makes it uncomfortable and noisy to be operating.

Anyhow, replacement genuine part was £300, no way was I paying that. Local engineering works advises it cannot be straightened any further as the bend is so slight and as a sliding splined shaft won't take kindly to heat or bending.

I've now picked up a brand spanking new shaft from the collection of bits below but its from a Deere and not Yanmar. Whilst the end pto splines appeared the same on close inspection the Yanmar has a couple of wide splines which only allows it to mount the pto shaft each end in one location.

I was going to split the spiders and remount the old heads, but turns out the trees are a different size also.

$_86.JPG.jpg


Plan now is to chop the ends of both shafts and weld in the new shaft to the old spider ends.
Question is, how do I ensure these are centred and that I won't set up a vibration from an eccentric shaft. I can see this being easier if I had a lathe to mount and centre the ends, but sadly nothing of such available. I don't fancy the thought of trial and error centring and welding, especially as it could leave me with two junked shafts.

I've no other pictures on the computer at the moment, but I'll get better of the existing and the replacement tomorrow and pop them up here.

Any experts (Graham Hookham, looking at you),have any bright ideas on how to set this up for centering and welding?
 
CPS

CPS

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#2
It can be done but really you want a lathe as you said, mainly to true up both parts that will be welded together. My suggestion is to take it to Rodney gettey in upperlands he'll sort you out;)(y)
 
Quattromike

Quattromike

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#3
Are the UJ's the same? Can you split the hardy spicers and swap the ends with the originals you need for it to fit?
 
Powerfab

Powerfab

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#4
Are the UJ's the same? Can you split the hardy spicers and swap the ends with the originals you need for it to fit?
Nope, that was what I had been hoping for but they’re marginally different.

Worst of it is, place old and new shaft together they look identical, and Yanmar make a lot of Deere parts.
It’s only when you get the calipers on them that the differences become apparent.
 
Powerfab

Powerfab

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#5
It can be done but really you want a lathe as you said, mainly to true up both parts that will be welded together. My suggestion is to take it to Rodney gettey in upperlands he'll sort you out;)(y)
Thanks Aiden,
I’m through Upperlands occasionally. Guess it’s not a massive trek from Antrim.
You don’t know anyone a bit closer to me by any chance?