Here is a link to a similar question about fixing a drifting joystick (they replace the whole joystick): [post|734992|new_window=true]
Here is the Reddit link from that post for a repair guide: [link|https://www.reddit.com/r/ValveIndex/comments/kf7mb4/guide_how_to_repair_your_valve_index_controller/|https://www.reddit.com/r/ValveIndex/comments/kf7mb4/guide_how_to_repair_your_valve_index_controller/|new_window=true]
Here is the Amazon Link from the above post as well:
[link|https://www.amazon.com/FJ06k-S-Sliding-Multifunction-Potentiometer-Direction/dp/B0945ZM5K2|https://www.amazon.com/FJ06k-S-Sliding-Multifunction-Potentiometer-Direction/dp/B0945ZM5K2|new_window=true]