Updated: Aug. 2, 2019
Tamron has only one service station in Japan where you can take your Tamron lens for repairs. (The Tokyo branch closed in May 2019.) You can also take it to a camera shop that can forward it to Tamron for servicing. They also accept mail-in camera repairs.
Tamron Repair Service
Address: Shimizu 3-3-2
Hirosaki, Aomori, Japan 036-8254
Web site: http://www.tamron.jp/support/repair.html