How ironic! I read this thread yesterday, and went 'humm, my 300 has an issue there'. Well, today, my stop-gap measure of 'fixing' this broke free as I turned the wheel. Luckily, I was stationary, and not moving!
I was outside, in 34 degree weather (or colder), trying to insert the replacement kit I scored at O'Reilly Auto Parts, but, the upper retainer would not budge as I broke off a screw in one of the slots where the screw goes in!
So, I did a Bubba move, I welded it together with 2 strips of steel! Yeah, not cool, but, it works for now. I will get the Flaming River Ujoint kit soon....