What torque is required on GMC steel wheels? What about aluminum wheels?
250 foot pounds for steeel wheels and 140 for Aluminum Alcoa wheels. I thought I’d pass along some information I found in my copy of “Fastener Facts,” a 100-page -publication by Bowman Distribution, a manufacturer of high quality fasteners. The book is available from Bowman – the price on the cover is $20, but a bunch of us here at work got them for free when we had a manufacturers rep here to put on a training seminar. It has a huge amount of information in it concerning bolts, including tightening torques. I just measured the wheel studs on my ’73 Sequoia – they’re 9/16-18 thread. According to the Bowman book, the torque for this size grade 8 bolt is 171 ft-lbs with dry threads, and 102 ft-lbs with lubricated threads. Their notes for the torque values include: torque values are based on the use of a through-hardened flat washer to provide a uniform, hard bearing surface; “dry threads” is defined as the zinc plating they put on their bolts; “lubricated threads” is defined as having Bo
