If one of the caps pop off of the fitting just to the left and behind the fitting circled, yes it will run rough. The one circled has no affect, you can pull all the caps off.
What Mike said above, if it isn’t broke don’t fix it. The u joints that are in there are probably better quality than what you would replace them with. If they’re good and tight, don’t mess with them. My ‘04 Frontier has 349,000 miles on it and it has the original u joints.
If it’s a divorced transfer case, which I think it is, I would drop them in together. I don’t have experience on the 4wd, but I do on 2wd 720’s and I always drop them in together. Just give the engine some tilt and use a jack on the transmission to raise it up as you slide it in. If you have someone helping you, it makes it all the easier. I hate trying to slide the transmission onto the engine when I’m laying on my back.
I had an ‘82, gas engine, a long time ago and it didn’t have a front sway bar either. The handling was terrible. I don’t see why a later model wouldn’t work. Are there sway bar holes in the lower control arm?
Years ago, I used door hinge bushings for my shifter, I think they were for a GM door. The diameter was right, but a little wide, so I had to use a file. The only thing I didn’t care for was that they were a little noisy, metal on metal. I guess that’s why Nissan used plastic.
Yes, that is one of the original versions of the dealer installed under dash a/c units. Looks like the one in my ‘70, that my dad bought new when we lived in California.
The pickup tube is blocked? I ran into this problem years ago on a 521. I used a coat hanger or a really stiff wire and kept jamming it in the pickup until it went all the way through. That cleared the line and I never had another problem with it. Just a thought.
Yeah, 521’s are meant for long trips. Although, when I was a kid, we to NC from California and my mom drove our 521 all the way here. It even had a cab over camper on it. Long trip! The truck was only 2 years old at the time.