After ~5 years of usage my favourite Beyerdynamic DT770 pro (250ohm) headphone’s headband sliders started to get hairline cracks. I read forums about this problem, its a very common issue. Original replacement parts also will crack so this is not the best solution for long term usage.
I realized, that Superlux HD660 has a same slider kit but seems to be more massive plastic material than new Beyerdynamic… So I bought an used Superlux HD660 for ~10€ and replaced it. Superlux HD-660 slider kit are 100% compatible with Beyerdynamic DT770 parts.
First you need to unscrew old part, newer Beyer models had Torx screws:
I also replaced this little plastic element, it slides off easily:
Same disassembly method with Superlux HD-660:
Im very satisfied with final results, I think it will be lasts more longer than Beyer plastic parts… Feels very good tight and it does not wobble like original parts. IMHO it looks better than original and 3D printed parts.