Loader M59 broken loader pin

[jonsstihl]

don't want to start a war but... If the pins are breaking at the grease groove, wouldn't that make the wear irrelevant. they must have been overloaded. the wear would cause slop in the articulation of the loader but does not appear to be the cause of the failure.

 

[ptsg]

don't want to start a war but... If the pins are breaking at the grease groove, wouldn't that make the wear irrelevant. they must have been overloaded. the wear would cause slop in the articulation of the loader but does not appear to be the cause of the failure.

I agree with you.

All I can see is regular wear on the pins, even with proper greasing schedule.

The weak point is the cross hole drilled for the grease along with the groove. It might be enough for a Kubota tractor that have quite a conservative lifting rating but on a TLB is not enough. I recon that these TLBs have much higher force than a tractor, so the stress on the pins is much higher.

 

[Hersheyfarm]

don't want to start a war but... If the pins are breaking at the grease groove, wouldn't that make the wear irrelevant. they must have been overloaded. the wear would cause slop in the articulation of the loader but does not appear to be the cause of the failure.

Thats a good point. Both of my pins that broke where on the grease channels. My stabilizer pin either cracked my frame or the cracked frame caused the pin to brake. The loader pin that broke broke, broke during a back drag over really hard cow stomped ground. Lots of vibrating.

Also, maybe lack of grease increases tolerance therefore allowing more flexing stress of pin that does not flex, instead of the shear stress hard steel tolerates.

 

[ovrszd]

don't want to start a war but... If the pins are breaking at the grease groove, wouldn't that make the wear irrelevant. they must have been overloaded. the wear would cause slop in the articulation of the loader but does not appear to be the cause of the failure.

My pins had minimal wear. They didn't appear to "twist" in two. They simply broke in the grease groove.

Again, I contribute my problem to the stress added with a Grapple. I just keep everything greased and keep an extra pin onhand.

 

[rScotty]

It's not that it broke that bothers me so much as where it broke. It didn't break where I would expect the shearing stress to be largest. If I am seeing the photo right, instead the pin broke along the grease groove, which would be right in the center of a bushing through the solid steel end of the loader arm. That's right where all the pin support should be at its best.

I wouldn't call that normal wear on the pin either. It might be normal for a 20 year old loader with 5000 hrs, but I don't see it a normal for a newish commercial duty TLB with 1000 hours & regular maintenance.

I think there's a problem there, that's it's fairly simple, and that we can figure this out and put it right.

Oh, BTW I didn't get around to pulling the pins on mine today. Maybe tomorrow....
rScotty

 

[Smokeydog]

Traded for this TL M59 about 2 years ago. 2014 model with 1060hrs. Up front I knew I was taking a chance on a machine that had poor to no maintenance. The value reflected the condition. Engine oil had been changed, hydraulic oil had not been changed and grease joints dry. Operated well and continues to after catching up on the maintenance.

Not surprised to see the wear, corrosion and condition of the pins from the past neglect.

Thanks for parts link. My dealer parts guy and manager told me backhoe bucket hangers for my B26 were not available without the bucket till I showed them the same morning. They showed me their parts drawing that didn’t show the bushings. Same dealer couldn’t find the bonnet protector and said it was no longer available. I’ll check with Messicks.

Some pin bushings are hard to replace requiring special tools to press and ream after install. Some tap in and out easy. Any experience with this type of loader?

Designing any equipment requires thinking about a weak link point. Rather have a $20 pin break than bend or tear major metal. Now if pins start to break routinely ..... maybe doing something wrong.

 

[Jchonline]

I grease my machine at every re-fuel so roughly 10-12 hours. How often do you guys grease your machines?

Same Mike. When I add fuel I hit the zerks. I have the Milwaukee battery powered so it is no trouble at all.

 

[Smokeydog]

don't want to start a war but... If the pins are breaking at the grease groove, wouldn't that make the wear irrelevant. they must have been overloaded. the wear would cause slop in the articulation of the loader but does not appear to be the cause of the failure.

Wear might increase the flexing of the pin under load thus increasing the cumulative metal fatigue over time. Scientific wild *** guess (SWAG).

 

[Smokeydog]

Many thanks to rScotty!
Called Messicks this morning and ordered a M59 Bonnet cover kit. $230+$30shipping. Had one in stock at another store. Checked to make sure hands on before taking order. Super helpful folks.
Messicks is going to get more of my business like for bushings in the future.

 

[rScotty]

Wear might increase the flexing of the pin under load thus increasing the cumulative metal fatigue over time. Scientific wild *** guess (SWAG).

It might. I think that is a good guess, but the problem with it is that the pen would flex more is if that wear was out at the ends - and there can't be any wear at the ends because the pin ends are bolted.... Still, worth thinking about.

Smokeydog, do you have any more pictures of the broken pin? I'd like to see some straight on and angle views of the broken end.
rScotty