Yanmar SA425 - First Real Issue; Three Point Hitch System

[aba4430]

The SA425 that I bought in 09/2023 has been super thus far with no issues. Last night whilst doing routine checks I noted an integral cast iron part of the the left axle housing stub, associated with the 3-point hitch system broken. See attached diagrams from Yanmar and my actual pictures. Contacted Yanmar this morning and also a local dealer with description and pictures. Not sure how and when this occurred as the part has never been disassembled since the mower deck lift linkage bracket installation by the selling dealer in 2023. I have not used any rear implements as yet, but have a Yanmar quick hitch attached to the three point. The right side axle housing picture is for reference only. Will update this thread suitably. Any other instances of similar damage etc. by other owners?

 

[oldnslo]

Did you by chance run over a rock or something solid enough to break that casting?

Looks similar to how my Branson is made and that ear is semi-exposed to impact.

 

[aba4430]

Did not run over anything that I can think of. No impact etc. that I remember. Because of the quick hitch installed on the tractor, the axle cover is quite protected during mowing and minimal loader, grapple and snow blade work I have done with the tractor. Reinstalled the mower after winter storage about a month ago. Have mowed a couple of times this year so far. No other damage etc. on the tractor. I will see what the dealer says.

 

[freightboy]

Is you quick hitch adjusted as to where the lower-links do not swing side to side? Loose three-point hitch with any weight on it can be like a hammer tapping the cast.

 

[aba4430]

Thanks for your reply. After the mower lift link bracket installation the entire assembly is very tight. Of course after this damage, there is some play now. I believe the tight assembly fit could potentially lead to binding of stationary part 19 and part 32 (see the second diagram in my original post) when raising the 3-point hitch up and down. This could exert torque to the locking pin that goes through the cast axle cover stub and pin. I cannot see traces of grease between the pin and part # 32. I have periodically sprayed liquid wrench or WD 40 on the balls of the lift arms (part # 23) since acquiring the tractor.

I installed the Yanmar QH in 2024 Summer and it was (there is some play now due to the damage) inherently taut with minimal play with exerted pressure.

I suspect if you do not have the MMM installed, this may not be an issue as there is some play that may prevent any binding; again just my preliminary assessment at this point. I have not heard back from the dealer as yet; did send them the pictures and a description per their recommendation.