Proof of Concept for S-Cam repair in BMT Member's Gallery - Click here to view our member's albums! 6 Posted April 12, 2018 I like your thread and photos. I have a '64 B61T with thread damage where the S-cam shaft and brake chamber mounting bracket attaches to the axle. The right side has one bolt in the bracket and a weld to hold the bracket to the axle. The left side has two bolts and that is it. The bracket is pulled away from the axle where the bolt is missing. I bought a new 5/8"-18 x 1-1/2" bolt, that matches what's on the left side, to try. The bolt enters the hole but the threads are getting knocked down badly. What is the thread count of a stock bolt? Is it the fine thread or course thread?