2012Arms forum
Missing retainers on EFP arm pin assemblies and their replacement
14 years old. Gear and prices may have changed since.
What the thread found
- When the pins holding arm sections together slide freely, the retainers are likely missing from the assembly.
- Automotive circlips can serve as temporary replacements in urgent situations, but original parts and professional service are preferable long-term.
- Two hex screws hold the pins in place by engaging against a flat section machined into each pin.
- The flat part of the pin prevents it from slipping through even with a loose hex screw, but the screws should be checked periodically as they can become loose over time.
- A second grub screw can be added after the first hex screw if the hole depth allows, or threadlock compound can be applied to prevent loosening.
- Bearings in older arm models tend to migrate from their original positions, including cable pulley bearings which are pressure-fit and difficult to reinstall.
Depends on
- The advice applies specifically to older EFP arm models.
- Temporary circlip solutions were not tested for reliability or safety.
- Some maintenance procedures require tools and expertise beyond owner capability.