I have a 1974 450sl that has a broken camshaft bearing holder retaining bolt. I plan on re-setting the torque on the new bolt and the other bolt on the camshaft bearing holder. Do I need to redo the torque on all the retaining bolts?
Thanks, Cam

Long (head), or short (stand only)? Already removed?

I'm not sure what you mean. I took out the broken bolt without removing anything else in the valve train.

Perhaps a pic of the place of origin of the bolt, and a pic of the bolt, would be helpful.

okay, I'll get some pics. The bolt is the lower bolt in the right, rear, camshaft bearing holder. Pictures to follow.

attached is a photo - I think. The screw driver is in the bolt hole and the broken bolt is on the towel.

mc:

You have a guardian angel who is not available to the rest of us!

At what point in the process did the head of the bolt separate from the shank? How did you get the shank out?

To answer your original question, only that bolt needs to be tightened to the final torque specification. Please use anti-seize compound on the threads.

I will be using some anti-seize if I can find mine. How about loctite if I can't? You are right about the guardian angel. I was amazed when I grabbed a little bit of bolt with some ViseGrips and it backed out. The head was broken off when I took the valve cover off to see where the noise was coming from. Thanks for your help, Cam

No Loctite please! The objective is to prevent the threads from seizing. Loctite, in effect, seizes the threads. Hypoid gear oil, or moly paste as an alternative to anti-seize.

Absent Marie Antoinette, we might well ask how the bolt came to lose its head. The most likely scenario, to my mind, is that the threaded hole in the block, being a blind hole, has a considerable amount of dirt/rust/oil accumulated at its bottom, preventing the screw from being run in for its full length. When the screw was stopped before the head was in contact with the bearing tower, additional, excessive, torque was applied until the head of the screw was twisted from the shank.
An alternate scenario has a bolt from an aluminum block engine being substituted for the original. The bolt from the aluminum engine is longer, and would bottom before the bolt head was seated. The underhead length of the wrong bolt would be 165mm. Measure the recovered, broken part.