Got new grommets to refit valve cover. They are identical to the old ones, just plumper and softer. -5 in my workshop today so they might just need warming up, but before I start: 

the grommets should just be a push fit over the bolt ridge so that they sit between the collar and the head?

Reason for asking is that feels very unlikely given the resistance I’m meeting at the bolt collar and the old ones are so compressed, cracked and hard there would be no point re-using.

Is there a trick to this?

Cheers, Stu

trick is ...cut the old ones off with side cutters

put some slippery stuff on the new rubbers before attempting to install them

just take them inside , fill the sink with warm water and dishwashing liquid ..and then attempt to fit them ???   just an idea

don't forget to degrease them first , or youll never hear the end of it  from "she who must be obeyed "   giggles

Once you feel the bolts meet resistance, don't tighten them more than a further 1/8 turn. If you do, you stand a good chance of cracking the cam cap. If you're worried that's not tight enough, I'm sure you've got a bottle of threadlock somewhere in the garage

Thanks Charlie. Actually had a brain wave: sat grommet on a 13mm socket, inserted bolt + wd40 and gently applied vice. Worked a treat.

Of course, If I hadn’t done that I wouldn’t have been able to re fit the cover, torque everything down to 5lbs and shear the last bolt!

Anyone know if the rearmost bolt in the spark plug recess is absolutely vital? 

Thanks as always Dai. Wish I had wifi in my workshop. Got to go out and buy ‘stud’ extractor...

Cracked Cam caps,   and my cracked casting.

This now has a stud in place.

I used new grommets, and hand tightened VERY carefully...


Bob

Sheared bolt drilled and helicoiled. Will never go near here with a torque   wrench again. The pinch point is quite obvious to the touch with a small socket. One bolt needed a further 1/16th of a turn after 700 miles but otherwise weep free.
Thanks all. Stu