Why is my Yeti not keeping ice anymore? The diagnosis, from cheapest fix to warranty claim

First, rule out the packing

Before you blame the cooler, ask whether anything changed. A cooler that held ice for four days with a pre-chill, block ice and a full load will hold it for two with a warm start, cubes and a half-empty box, and that is not a defect. It is also worth calibrating against what the cooler was ever supposed to do: OutdoorGearLab measured the Tundra 45 at 98 hours to 40°F sealed in a lab, and Switchback Travel's field rule is to expect about half the maker's claim in use. If the cooler is holding two days at a July campsite with the lid opening, it is fine. How long does a Yeti keep ice has the numbers by model; how to keep ice longer is the checklist. If it genuinely used to do better under the same conditions, continue.

Coolers: gasket, latch, lid, plug

1. The gasket. Open the lid and run a finger around the freezer-style gasket in the lid channel. It should be soft, round in section, and continuous. Flattened, cracked, hard, or pulled out of its channel at a corner means air is getting in. This is the most common cause on a cooler over three years old, and it is a part: Yeti sells lid gaskets for Tundra and Roadie; RTIC sells them by size for Ultra-Tough. A paper test helps: close the lid on a strip of paper at several points and pull; it should drag everywhere.
2. The latches. T-latches stretch. If the lid lifts a hair with the latches closed, or you can rock the lid, the latches are no longer compressing the gasket. Yeti's document literally anticipates this (“need to upgrade your T-latches”); it sells the pair, RTIC sells its own, Engel sells a stainless kit.
3. The lid. Set a straightedge across it. A lid that spent a summer in a truck bed can warp enough that a new gasket cannot close the gap. This is not a part; it is a claim inside the term (arguable as a defect, arguable as heat abuse) or a new cooler outside it.
4. The drain plug. A lost o-ring or a cross-threaded plug lets meltwater and air move. Cheap: Yeti, RTIC and Engel all sell the plug.
5. The hinge. Rare, but a hinge pin walking out lets the lid sit crooked. Yeti's Tundra hinge is a stainless rod; a bent one is a claim.

Tumblers: the lid, then the vacuum

A Rambler, a Stanley or an RTIC tumbler that used to keep ice all day and now doesn't: first the lid. A MagSlider with a lost magnet or a bent slider, a Quencher FlowState with a cracked cover, a straw lid with a split straw, or a gasket in any of them that has dried and shrunk lets air move over the ice all day. Pull the gasket, wash the channel, reseat it; if it is hard or cracked, replace the lid or the gasket (who sells which). Second, and much rarer, the vacuum. A double-wall tumbler that has lost its vacuum stops insulating entirely: the outside sweats with ice water and gets too hot to hold with coffee. That is the one drinkware failure every term on this site names: Stanley's lifetime term “covers degradation of thermal performance,” Zojirushi's 5 years is specifically “on Stainless Steel Vacuum Heat Retention,” YETI's 5 years covers defects in the product. A sweating tumbler is a claim, not a cleaning. How to clean a tumbler lid and straw is the gasket routine.

Claim or part?

Whether a specific failure is a defect or wear is the maker's decision under its terms; Yeti's and RTIC's are quoted in full.

The parts