86 broken rocker arm shaft

[mtmtntop]

i'm not certain that the motor is from an 86, but twice, on 2 different cars I have had the rocker arm shaft break. i have fsm and followed the torque sequence and half turn at a time instructions. is this bad luck or bad installation. The donor motors have 150-200,000 miles.

[dlb]

Weird. Are you using a torque wrench? If so I wonder if it's way out of spec.

[mtmtntop]

i have one of those clicker torque wrenches. but good idea. i'll check it against my son's to see if its the same or not.

[Mark]

I was using a torque wrench at work 2 days ago. It was one I had used before without a problem. I was turning a bolt and it seemed that I was applying more torque than the setting (25 inch-pounds). I put the socket in a bench vise and turned hard, but it never clicked. I tried several settings and it still never clicked. That was the first time I've come across a torque wrench that turned itself into a regular socket wrench. It makes me trust them less now.

[xirdneh]

Has the head been warped hence re-surfaced? More than once? Top of head may be warped too. Surfacing the head takes care of the mate to block but the top end of the head may be too warped. That can bind the camshaft and rocker shaft assy.