Had a minor crash and shifting a bit off with my GX Transmission rd. Does the cage look bent? Just looking for a yes or no. Thanks!
Hard to say from that angle but more likely you just need to realign the two lines on the derailleur bolt.
Shop mechanic here. As Craig_Wu said, the derailleur is designed to rotate backwards if impacted straight back. It opens the B-gap way up so shifting will be sluggish. You may need to repeat the setup procedure for T-type. It’s important to torque the bolt to 35Nm to achieve the correct clamping force/friction on the full mount, so it can be tough if you’re a basic home mechanic and don’t want to buy a torque wrench. You can use a Sharpie to mark the bolt before you loosen it, and then return it to that same spot, but it’s not ideal.
The other part of the answer is, yes, the cage is bent. Intentionally. Current SRAM and Shimano 1x have some deliberate shaping in the cage so when the der is in the 10T cog, the lower pulley wheel is aimed inward at the chainring. When the derailleur is in the 52T cog, the lower jockey wheel is aimed outward toward the chainring. The narrow-wide teeth are very blocky compared to the chamfered teeth on the older drivetrains so the chain needs a straighter shot when feeding from the bottom of the chainring to the derailleur. It’s pretty much impossible to diagnose a slightly bent derailleur with a visual inspection these days.
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I know 100% someone made a Transmission cage checker (probably 3D printed) since it is intentionally bent, so even brand new it can be disconcerting. I just can’t recall who off the top of my head. Surely @Dave_Rome will know
edit: made by Leap Components! https://leapcomponents.com/product/sram-t-type-derailleur-alu-cage-checker/
Yep, that’s correct - Leap Components.
Previously covered it in a Threaded edition: Threaded #30: One more New Tools Day for the year