I thought this topic worthy of it's own research thread as there seems to be very little info on plastic pin injection and the 1st gen Camaro.
At first I wasn't sure about my drive shaft, but after 'Big Iron' Bob mentioned that he has a known original 68 BB/TH400 shaft [he bought the car new] with the same plastic injection, I suddenly have lots of questions surrounding the topic.
All the pics that others have contributed so far in the driveshaft thread http://www.camaros.org/forum/index.php?topic=7861.0
are all sb shafts with outboard snap rings.
So, when did GM use plastic injection and was there some design criteria that required it, or was it purely economics?
If economics, why [seemingly] only BB's?
Was it only BB/TH400 cars?
Was it all 1st gen BB's
Research I've done so far suggests that ony GM did this and it's not just a 'pin' of plastic, but that there is a groove in the trunnion caps and matching grooves in the yokes. Plastic is then injected through the holes to fill the grooves.
It seems they are quite tough to get apart. The common removal method I've seen so far is to heat the yoke with a propane torch to melt the plastic as per this youtube video http://www.youtube.com/watch?v=YZZUjzNCPF0
which seems a bit harsh!
This site http://arrc.epnet.com/autoapp/8844/8844R07_U_JOINT_REPLACEMEN1.htm
shows using a cross press arm pressing onto the spider [fig 4.] to sheer out one side at a time.
This not only avoids heating anything, but would maintain an aspect of originality as the 'pins' are left intact
All input warmly appreciated
A couple of pics of what mine looks like