That looks to be a "Stanpart" trunnion, so unless it's a very, very sneaky copy it should be good quality. That's what I look for when buying spares anyway.
It's difficult to go on a photo but my first thoughts were that it all looks too "clean and dry", mine typically look a mess with oil/grease coming out of the top once they are in use. Have they been oiled or greased yet ? I don't mean a skim to assemble, I mean put the grease gun on and squirt until you see some come out !
The rubber looks like it's aged and hardened which has caused the splitting you see. Normally rubber shouldn't split with jagged cracking like that and the multiple cracks tend to make me think it's a material property problem rather than just being too tight.
I've no idea what the correct number of turns should be when putting them together. All I do is tighten them up as far as they'll go without pressure, then back it off until it will go full lock either way by hand pressure on the trunnion without binding. Hard to describe but if you think of the operating sweep they need in practice then it will just suddenly come to you when you're straining the joint.
Personally I'd just replace the rubber seal, check range of movement and try again. I can't remember seeing any markings on individual trunnions but it's a while since I last did that job. For some reason I seem to think they have right & left hand threads on the links, and if that's the case then if you can't screw it on, it goes on the other side !
The workshop manual covers the front suspension quite well, it's in the base S2 manual. Worth a scan through if this suspension design is new to you.
Brian
