That would be the 68 Camaro. I also have a 62 Nova and my wife has a 68 Mustang. Here are some pics of those. I'll get a pic later today of what is under that acorn nut.
Dunno, but it is in the right spot to hit a detent. Might just need a new spring and/or ball bearing.
It does look like an adjuster under the acorn nut. But it seems to be working more like I expect now. Since I started this thread I have moved it twice. Both times when we first set it up we had the back a little lower than the front and both times on the retract cycle hydraulic fluid gushed out of the air breather. Once I leveled it that quit. So I'm wondering if it might have been a little over full and now that some has come out it is working better?? If I want to try to adjust it which way would I turn the slot?
It shouldn't take much...1/4 - 1/2 a turn would be my guess...make sure you note where it was so you can go back there if it turns out to be something else...but it looks like a detent to me...