Landlord 20 DLX - Broken Front Wheel Spindle

Without bad luck I'd have no luck at all.

I bought what I believed to be a well-maintained 2000 Landlord 20 DLX with around 680 hours on it. After a whopping 15 minutes mowing, the front left wheel spindle snapped and turned the tractor into a trike. I've never seen this happen before and was fairly dumbfounded.

I have a new spindle ordered with delivery expected later this week.

Am I correct in assuming this is a straightforward repair as described in the service manual?

Anyone else have this experience or have thoughts on the cause? The previous owner claims good routine greasing maintenance.

The picture of the break point below makes me think the part was never fully welded as there is half of the cross section rusted. Are these spindles really two pieces welded? I'd assumed they were one solid piece from wheel to splines.

https://www.simplicitymfg.com/na/en...s.productmanuals.html?searchrequested=1693383

https://www.google.com/search?q=sim...ome..69i57.28863j0j4&sourceid=chrome&ie=UTF-8

how do bearings look?

for Safety use a jack stand.

No where near enough resolution to make any comment about the fracture except that there had been a crack for about 1.2 the cross sectional area for some time as denoted by the rusty region and the fracture surface looks like it could have been a brittle failure as there does not appear to be any necking.
To do any meaning full analysis I would need several photos taken much much closer and with the camera on a stand.
Doing macrographs of fracture surfaces with a phone camera is very hard as they do not have the depth of field required to see sufficient details to pick up on the charasteristic patterns of the various mechanisms of failure.
When making warranty claims I have always resorted to my Hasselblad because I am yet to find any digital that produces a clearer image.
And then there is the intimidation factor when the technical division gets a letter with lots of clear crisp glossy 5 x 4 with the circles & arrows & the parragraphs on the back of each one, as Arlo Guthrie would say.

Usually he front axel would not be welded.
Generally the steering stem & axel is one piece either forged or bent then the other bits are welded to it.
Much stronger , cheaper & quicker to make.

mechanic mark said:

how do bearings look?

for Safety use a jack stand.

Click to expand...

I haven't taken it apart yet but will do full inspection and report back later this week.

bertsmobile1 said:

No where near enough resolution to make any comment about the fracture except that there had been a crack for about 1.2 the cross sectional area for some time as denoted by the rusty region and the fracture surface looks like it could have been a brittle failure as there does not appear to be any necking.
To do any meaning full analysis I would need several photos taken much much closer and with the camera on a stand.
Doing macrographs of fracture surfaces with a phone camera is very hard as they do not have the depth of field required to see sufficient details to pick up on the charasteristic patterns of the various mechanisms of failure.
When making warranty claims I have always resorted to my Hasselblad because I am yet to find any digital that produces a clearer image.
And then there is the intimidation factor when the technical division gets a letter with lots of clear crisp glossy 5 x 4 with the circles & arrows & the parragraphs on the back of each one, as Arlo Guthrie would say.

Usually he front axel would not be welded.
Generally the steering stem & axel is one piece either forged or bent then the other bits are welded to it.
Much stronger , cheaper & quicker to make.

Click to expand...

Agreed on all points. After 19 years there's no warranty to worry about so just satisfying my curiousity at this point.

Take some better photos & I might be able to help .
In a previous life this was part of what I did for a living

bertsmobile1 said:

Take some better photos & I might be able to help .
In a previous life this was part of what I did for a living

Click to expand...

Will do... Earliest I will be back at that house is Friday.

bertsmobile1 said:

Take some better photos & I might be able to help .
In a previous life this was part of what I did for a living

Click to expand...

Got the part early and repaired the tractor today.

Here are the better pictures of the failure you requested.

Fatigue fracture initating from a bad weld at the rusted end.
there are 4 facture zones
Right at the bottom of the rusty region there is a smooth crack about 1/4 of the height of the rusty section.
That is where the failure started and it is a stress crack either from the bending or the welding.

Then in the rest of the rusty area you can see lines running left right, sort of like waves on a beach.
There are the stages of cracking.
There will be a lot more than what you can see in the photo and they are fatigue.

Right above the rusty bit a a very rough patch which is where individual loads on the spindle were slightly greater than the strength of the steel so it stretches and tears, thus the rough look of the fracture surface.

Finally the remaining cross section of the steel was so small a single load event was greater than the shear strength so you got the flat looking brittle fracture & ultimate failure of the shaft.

So it should be a warranty repair as the assembly was faulty from new but don't hold your breath waiting for it.

That is the best I can give with what you posted and to be frank, the only real question is why the crack started in the first place and for that I would need to do some micro hardness tests and etch the surfaces .

Electric welding is a very violent process as far as the steel is concerned and a weld can very easily cause a crack if the stresses are in the right planes and there was no post weld heat treatment.
The axel assembly is usually forged or bent hot which from a strength point of view end up being quite similar.
If the axel had a bearing ( ball or roller ) then as bent condition would be fine.
If it has a bush then it needs to be hardened and that can also cause cracking.

Or it just could have been a bad piece of steel with some inclusions in there (the etch should reveal that ).

The engine & the deck both generate lots of vibrations but they should not be transmitted to the axels as the wheels have a fair bit of play.
Running with hard tyres or too fast over rough terrain can also cause shock loads in the axels.
Any more information & I will need to send you an invoice :laughing:

bertsmobile1 said:

Fatigue fracture initating from a bad weld at the rusted end.
there are 4 facture zones...

Any more information & I will need to send you an invoice :laughing:

Click to expand...

That makes sense.

Now I have to decide whether or not to keep rolling the dice with the other spindle, order another replacement, or just plan on replacing the whole front end with a different setup as these things clearly can't be trusted. OTOH, 19 years out of a part isn't too bad although folks routinely are getting 60 years on other units!

Thanks for the interesting failure analysis.