Bambu Replaces AMS 2 Pro Feeder Units From a May to July 2026 Batch

What Bambu found

On October 27 at 07:05 UTC, Bambu's support team posted a service notice in the official Bambu Lab forum. Owners had reported that the gears in their AMS 2 Pro feeder units were wearing out faster than expected. Bambu traced it to a batch of feeder units made between May and July 2026 that, in its words, “didn't get enough grease coverage during production.” Bambu's wiki FAQ adds that the issue has been resolved and that units currently sold through its official stores are not affected.

Every AMS 2 Pro has four feeder units, one per slot. Bambu's replacement guide describes the feeder unit as the device that “provides the first-order driving force for the AMS,” so it is the part that actually moves the filament. Bambu says it cannot tell exactly how many units are affected, so it is replacing the feeders on every AMS 2 Pro in the batch, not only on units that already show wear. According to the FAQ, the issue involves only the AMS 2 Pro and does not affect normal use of the printer itself.

Bambu has already sent owners of the batch a message with step-by-step replacement instructions through MakerWorld and Bambu Handy. No message does not mean you are in the clear: the FAQ asks anyone who thinks their unit could be in the batch to check the serial number.

Signs of worn feeder gears

Bambu's notice and FAQ name three signs:

• Gears wearing out faster than expected. This is what owners reported to Bambu. Bambu gives no figure for how much faster.
• Powder from the feeder gears. Abrasion from worn gears. Bambu asks you to contact its support promptly so it can assess the unit.
• Loading or unloading problems. Same advice: open a support ticket instead of waiting for the replacement parts.

Loading trouble has everyday causes too, from debris on the feeder gears to a tangled spool. Our AMS detection guide walks through cleaning the feeder gears, and the AMS jamming guide covers stuck filament. Whether your AMS 2 Pro is covered does not depend on symptoms, though, only on its serial number.

How to check your serial number

1. Find the serial numberBambu's FAQ says it is on the AMS 2 Pro frame and on the printer screen, where connected AMS units appear in the same menu as the printer's own serial number. Bambu Studio lists connected AMS units under Device → Update.
2. Enter it in Bambu's registration formThe form, “Bambu Lab AMS 2 Pro Feeder Unit Replacement Registration,” is linked from Bambu's service program FAQ. It tells you whether that serial number is covered, and Bambu treats that result as final, whether or not you got a message in MakerWorld or Bambu Handy. With several AMS units, enter each serial number; the form takes more than one. If it keeps sending you back to the sign-in page: several owners in Bambu's forum thread reported that loop on October 27, Bambu's staff suggested a private browser window, and other owners said the form worked for them (user reports, not a statement from Bambu).
3. Use the account linked to the AMSBambu recommends it so it can verify the device. Bought from a reseller, received as a gift or bought used? Still eligible: the serial number counts, not where the unit was bought. Each serial number can be registered once, so if a previous owner already registered yours, contact support.
4. Wait for the ticketBambu reviews the registration and opens a support ticket within 1 to 2 business days, visible in Bambu Handy and on Bambu's website. Tracking appears in the ticket only once the parts have shipped. Submitting the form again does not speed anything up; address changes and a mistyped serial number go through that ticket.

What you get

What Bambu promises for each covered AMS 2 Pro, from the forum notice and the wiki FAQ:

Feeder units bought separately as spare parts are not part of the issue, Bambu says; the program covers only the feeders originally installed in the affected AMS 2 Pro units. Bought through a reseller, including as a business? You still register directly with Bambu, and Bambu sends the parts and the code itself.

What to do until the parts arrive

• Keep printing if the AMS works normally. That is Bambu's advice in both the notice and the FAQ.
• Watch for powder and loading errors. If either shows up before the parts arrive, contact Bambu support rather than waiting.
• Swap when it suits you. Once the new feeders are there, you can fit them right away or keep the originals until they show wear; Bambu leaves the timing to you.
• Know what the swap involves. Bambu's replacement guide lists an H2.0 and an H1.5 hex key and 20 minutes. Power off the printer and disconnect the AMS first. You lift out the AMS main frame, and for slots 2 and 3 you also loosen and turn over the mainboard. If a part breaks during the swap, stop and contact support.
• Check the result. Bambu's test: connect the AMS 2 Pro to an idle printer with the 6-pin cable, insert filament and load it from the app or the printer screen. If loading finishes without an error message, the swap worked.
• Just bought a covered unit? You can return or exchange it within the return period of the store or platform you bought it from; for a reseller purchase, that goes through the seller. Bambu suggests exchanging only the AMS 2 Pro, not a whole printer bundle, though some platforms accept only whole-unit returns.

Buying an AMS 2 Pro now

Bambu posted the notice on the same day its Black Friday sale started (see our Black Friday 2026 guide). If you are buying an AMS 2 Pro or an AMS 2 Pro bundle now, Bambu's FAQ says this about where it comes from:

• Bambu's official website: units sold there directly are not affected.
• Authorized resellers: Bambu says it has isolated their stock from the batch.
• Other resellers: a small number of units from the batch may still be in their stock. Check the serial number after delivery; a covered unit can be registered like any other, or returned within the seller's return period.

What is still open

• How many units are affected. Bambu says it cannot say for sure.
• The serial number range. Bambu has not published one; only the registration form answers it for a given unit.
• Which bundles shipped with the batch. Bambu does not say whether printer combos with an AMS 2 Pro were among them. The AMS serial number decides either way.
• When the 3 to 5 weeks start. The notice says “over the next 3-5 weeks” from October 27; the FAQ does not say whether that counts from the notice or from your registration.
• Whether the sign-in loop is fixed. Bambu has not commented beyond the private-window tip.

We will update this article when Bambu adds details.

Sources

• Bambu Lab forum, “Service Notice for AMS 2 Pro Feeder Unit” (posted October 27, 2026, 07:05 UTC, by Bambu's support team; replies on the registration form read October 28, 2026)
• Bambu Lab wiki, “Service Program for Feeder Units in Certain AMS 2 Pro Batches” (last edited October 27, 2026; read October 28, 2026)
• Bambu Lab wiki, “Replace AMS 2 Pro Feeder Unit” (read October 28, 2026)
• Bambu Lab wiki, “How to Find and Register the Serial Number” (read October 28, 2026)
• Bambu Lab forum, “Black Friday Sale 2026 is officially live!” (posted October 27, 2026, 12:00 UTC)
• Shipping window in Fig. 1: our arithmetic, October 27 plus 3 and 5 weeks