M30 con rods

[Victor Johnstone]

Con rod caps and studs. Yet another question. Started re-assembly. New nuts and washers. 3 nuts fitted well leaving around 1,5 threads visible above the nut. 1 however tightened with the threaded part of the stud not clearing the nut (about 1 thread short). I decided to take it apart to look. The stud itself came out. I notice the rod end of the stud has a hole drilled. Finally, my question: are these studs single use? Any other ideas? Thanks all.

[Groily]

The studs are drilled because they are cross-pinned in the trunnions. The pin normally has to be removed to allow the studs to be unscrewed. If it isn't, then the threads get wrecked. (DAMHIK - it was a long time ago and I was very ignorant!) The two studs shoud be the same length.
I don't regard them as single use, but if they are waisted or there is any sign of anything, too critical to ignore.
Something is up with that one of yours, and further action needed I feel certain.

[Victor Johnstone]

Thanks Grolly. The two studs are the same length. I didn't realise that there was a pin but I wasn't trying to remove the stud. It just came out. Daft question maybe. Is the pin just held in by friction?

[Groily]

They're a tight fit IIRC, and need a good whack with a punch of the right diameter, but not held in by anything else. Don't THINK they're tapered, but it's a good while since I had to go into one of these. All I do know from bitter experience and pig ignorance long ago is that if you try to extract one with the pin in without realising . . . the threads are wrecked! I think, again from memory, that new steel trunnions and studs are available (or were) I think - again, only think - I got some from Steve Surbey. Haven't checked on current availability, but someone has been in there before you, and it might be worth replacing, to be sure. Absolutely the last thing you want coming adrift, after all!

[Victor Johnstone]

Ok thanks again. Agreed a loose end cap wouldn't be a good thing!

I will check with spares who have been brilliant so far.