Not trying to be argumentive - guess we're both limited by the written word and other challanges commuicating from afar.
Why is it hard to install the ujoint with the strap in place?
It's not on the caps that go into the driveshaft.
Guess that is where we're not seeing the others perspective. I've always had to remove the caps to install a U joint in the driveline, transmission yoke and though don't have to at the rear would remove the retaining strap from the caps so that it can be installed if I ever used some of the early replacements.
I can't install a U joint (guess just not a method I'm aware of) between the transmission yoke and driveline with the strap on. U joints are front or rear only they have different applications. On one car they might be correct for the front connection while on another the rear.
And why would they have to remove the strap holding the caps on?
If the ujoint is installed with the strap facing forward it's not in the way of anything, and if it's facing rearward the yoke on the rear end is cast to allow for it.
As said above if installing in the driveline or trans yoke I only know of methods of installation where the caps have to be removed so that the U joint can be situated between the eyes and the caps installed from the outer surface towards the U joint and seated.
In your third paragraph, are you referring to the slip yoke or the pinion yoke? And what exactly are you referring to as the driveline? I don't mean any disrespect, I'm just trying to understand what you're saying.
Red arrow - driveline Green arrow transmission yoke.
Rear end yoke
Or maybe I wasn't clear that the strap was only on the 11/8" caps on the rear u-joint meant for the rear end yoke? The ujoints in the pictures I posted are front (top) and rear (bottom) sets from three driveshafts.
I think this is where we separated. I'm mentally comparing the NOS U joints we've seen with the straps to the pictures that your showing with the straps. But your suggesting/sharing that you believe the straps on your examples were different and for a specific location.
Yours are the first I've heard of installled with the straps left in place. We do have pictures of the rear (don't know what size but guess we could guess and look them up) of the straps being in that location prior to the installation of the driveline in the car originally. Something to "chew over "