u- joint broken

[Timo AH]

Greetings from Finland. My 230 sl-66 broke down in a roundabout month ago. Today finally I had time to remove rear axle and the reason for broke down seems to be u-joint. See picture.
The rear axle was renovated few years back (all bearings, sealings, u-joint sleeve was replaced also because there was some play in the right hand rear wheel. U-joint was not replaced on that time)
Any thoughts what could cause this? is it aging related issue or could u-joint failure caused by some mistake in rear axle renovation few years back? Also securing bolt is cut.
I just remember that we didn't found right torque specs for locking bolt on that time and we used 60 Nm and added loctite glue.
All ideas about possible root cause and next steps are more than welcome.

Timo 

[ja17]

I have seen this exact same failure happen on other rear axles over the years. It is rare but seems to be a weak point in the design. I think your renovation was not the cause. Maybe just bad luck. You should be able to source a good used one since this part was used in many of the common MB sedans of the era.

[Timo AH]

Thank you very much. Any ideas how I could get out broken bolt and where I could find the right torgue setting. Last time we used 60 Nm.

Timo