I was all set to cut the grass and enjoy a beer on the deck wen done and this happened

[muncybob311]

Here are some pics after a bit of cleaning. The QA plate looks OK? I cannot see any stress fractures?

 

[ponytug]

Here are some pics after a bit of cleaning. The QA plate looks OK? I cannot see any stress fractures?

I think you were just really unlucky. I also suspect that there was probably a metal defect in the axle, and you clipped it just right to shear it. I can't see any sign of a pre-existing crack that spread in any of your photos.

I think that in the hands of a great welder with the right tools, anything can be welded. That said, I think that welding at your break is a high stress location and I think it would require cutting enough of a gap to weld in, and then a great welder, but even then there will be a heat affected zone that will be prone to failure. I wouldn't go that route if it were me.

I suspect that the repair is a new axle, then gouging or plasma cutting the old end out of the Q/A plate, and then welding the new one in. That would be fairly easy for a competent welder, and would get the heat affected zone away from the highest stress area.

Good luck!

All the best, Peter

 

[RayIN]

I think that in the hands of a great welder with the right tools, anything can be welded

Yep. I watched a man weld 2 sections of aluminum wrapper out of a pack of Pall Mall's together.
Others were betting on the outcome. That Navy-trained welder won nearly $1,000 with that feat.

 

[CliffordK]

That looks like a pretty wicked grain structure, but I'm not quite sure what what it would be like to break the unbreakable.

I assume the part with the nut can just be knocked out towards the nut... hopefully. Then once off you can try to salvage the nut.

That is an interesting method to use a short sleeve between the base plate weld and the pivot point which effectively isolates the heat affected zone.

Would rounding the corners slightly on that short sleeve help reduce the single point stress riser?

A good machinist should be able to build the part from scratch. Basically sizing and threading a rod. And then get it welded on. I'd do it all in the machine shop.

I'd be tempted to go with steel that wasn't the original steel that failed.

 

[RayIN]

That looks like a pretty wicked grain structure, but I'm not quite sure what what it would be like to break the unbreakable.

I assume the part with the nut can just be knocked out towards the nut... hopefully. Then once off you can try to salvage the nut.

That is an interesting method to use a short sleeve between the base plate weld and the pivot point which effectively isolates the heat affected zone.

Would rounding the corners slightly on that short sleeve help reduce the single point stress riser?

A good machinist should be able to build the part from scratch. Basically sizing and threading a rod. And then get it welded on. I'd do it all in the machine shop.

I'd be tempted to go with steel that wasn't the original steel that failed.

Depends, I always want the first part to break to be the easiest and cheapest to replace.

 

[CliffordK]

Depends, I always want the first part to break to be the easiest and cheapest to replace.

True, and I've wondered about upgrading things like upper and lower control arms on vehicles that seem to get rapidly destroyed in an accident. If the control arms are made stronger, then perhaps one would have a more costly frame repair.

 

[muncybob311]

So I spoke to Terry and he thinks a good welder can take core of the repair. Apparently the "axle" has a shoulder on it between the ring and the QA plate which keeps the axle stationary. We should be able to grind the ring bracket off the QA plate, pop out the small piece of the axle and the larger piece from the mower deck itself and reinsert the new axle and then weld back onto the QA plate. I asked if the heat marking on the inside of the QA plate is a problem since the small ring will be welded onto the same spot and he said no.

Just waiting to hear if they have the axle in stock, otherwise it's a whole assembly and 4X the $$.

 

[ponytug]

So I spoke to Terry and he thinks a good welder can take core of the repair. Apparently the "axle" has a shoulder on it between the ring and the QA plate which keeps the axle stationary. We should be able to grind the ring bracket off the QA plate, pop out the small piece of the axle and the larger piece from the mower deck itself and reinsert the new axle and then weld back onto the QA plate. I asked if the heat marking on the inside of the QA plate is a problem since the small ring will be welded onto the same spot and he said no.

Just waiting to hear if they have the axle in stock, otherwise it's a whole assembly and 4X the $$.

That sounds like progress.

If it turns out that PT doesn't have the axle in stock, and you have access to a good welder, if it were me, I would price out the alternative.

All the best, Peter

 

[CliffordK]

So I spoke to Terry and he thinks a good welder can take core of the repair. Apparently the "axle" has a shoulder on it between the ring and the QA plate which keeps the axle stationary. We should be able to grind the ring bracket off the QA plate, pop out the small piece of the axle and the larger piece from the mower deck itself and reinsert the new axle and then weld back onto the QA plate. I asked if the heat marking on the inside of the QA plate is a problem since the small ring will be welded onto the same spot and he said no.

Just waiting to hear if they have the axle in stock, otherwise it's a whole assembly and 4X the $$.

Thanks. I was wondering if it was a hole through the backing plate and a weld on the back side, although it looked smooth in the photos. Apparently not.

Grab a spare ring when you do it.