Does my AMS feeder unit need replacement if I am outside the noted batch window?

For units delivered in late August, you are technically outside the specific manufacturing window they cited, but since the issue stems from poor assembly rather than just date stamping, I'd advise checking the unit itself rather than relying solely on the shipping box. It's not guaranteed to be safe just becuase you missed that narrow timeframe; variability in quality control can happen slightly before or after the main production run. The wear happens when the grease doesn't penetrate the critical gear points, which is a physical defect that might extend beyond the official dates.

If the box is useless, you need to physically examine the feeder unit. Look closely at the plastic housing where the motor assembly sits. Manufacturers often apply a serial or batch number stamp directly onto the chassis or near the power connector. Sometimes it's a short string of alphanumeric characters, often labeled with a 'SN' or 'Batch' identifier. Pull it apart gently enough to see the internal components, which sometimes have a more detailed manufacturing stamp than the exterior casing. This internal ID is ussually the definitive way to prove the unit's provenance. If you are unable to find a clear batch code, the next step is contacting support and providing them with the full serial number of the device. Even if the serial number itself doesn't match the affected production slot, having the serial number allows them to cross-reference the unit in thier internal manufacturing database. They should be able to tell if your specific machine fell into that deficient production run. Since they are offering replacements for the entire batch, even if your specific feeder is still spinning fine, the risk of future failure is likely too high for a unit that was assembled with known insufficient lubrication. If the unit is old enough, swapping it out proactively is the safest call to ensure long-term reliability.

I went through this whole exercise with my own unit a while back and ended up just opening the feeder housing to eyeball the gears directly, since the batch code on mine was printed on a label that had half peeled off anyway. If the gear teeth look shiny and lightly coated rather than bone dry, you are probably fine, and a cotton swab with a small amount of PTFE grease takes two minutes if you want extra peace of mind. My question for anyone who has actually had a failed one is whether the wear shows up as audible clicking during filament pulls first, or if it just quietly grinds down until the feeder starts skipping.

Support cleared mine in like a day when I sent the serial over chat, so I'd do that first before cracking anything open. The rep looked it up and told me straight away my unit was from a later run. While waiting on the answer I checked mine with a bright flashlight angled through the vent slots on the feeder and coud actualy see enought of the gear train to tell it wasn't dry. If you end up wanting to add grease yourself later, go easy, a thin film is all these little gears need and packing it in just attracts filament dust.

The other thing I'd add is that these feeders usually tell on themselves before they actually fail. Mine was dry for who knows how long and the first sign was a faint clicking on multi-color prints, then the AMS started failing to pull filament through the PTFE tube. That was after roughly 60 spools, so if yours is quiet and feeding clean, you have time to sort the serial number check at your leisure. Keep an ear out for clicking or grinding when it rewinds a spool, that's your early warning.

Quick update - I decided to go with the support suggestion and sent my serial number over chat. It turned out the problem wasn't my fault and my unit was confirmed to be from a later production run. No need to worry about those gears.