Got dam ab_slack you are full of information! Thanks alot! You have cleared up everything really well

! And about driving in the rain with 4wd is that recommended? I live in socal so its almost always warm but just to be prepared for the rain next time .
I may have some info there, but mind is mostly a lay persons understanding with just 26 years of history with BIIs and combination of shop work and my own work. There are some real mechanics here that probably cringe at what I say at times... I've gotten lots of help from em.
As for the question, 4WD on these is not recommended in the rain. They aren't a full time 4WD system. There is no differential between front and rear so when the net speed between the front and rear wheels is different (such as when going around a turn since the front and rear take different paths, or having different size tires) there needs to be some slip someplace between tires and the road or the tension winds up in both front and rear drivelines until something gives.
When in snow, dirt or mud, there is plenty of slippage at the tires to let that tension out before it gets significant. Wet roads, while having some slip, are still better than snow or dirt so you can still get tension that will build up and be released by a wheel sliding. Some stiffness may be felt when turning and since it actually forces a tire to slide a bit, it is probably affecting driving stability in a negative way than actually helping.
Even on dry pavement when the tension gets built up, it will usually release by a tire slipping without causing mechanical damage. It will be felt as a sort of chattering around turns. It isn't good at all. Rain it still does that a bit.
What you can do in the rain however, if hubs are locked, when accelerating from a stop on a wet road, particularly when sitting on an uphill where wheels will slip, it isn't a big deal to put it in 4WD just to get the extra traction. Once it is rolling slip it back into 2WD. Even if you are making a bit of a turn. It is a trade between getting some grab verses a little slip caused by being in 4WD.
To head off the question, what about a road with mixed wet and snow, or mixed dry spots and icy spots? I usually use some judgment. If I can't go 10 more than a couple seconds without at least one wheel on snow (only take one to relieve the tension) I will keep it in 4WD. If it is longer than that I may move it into 2WD. It all depends. If it is wet patches, I am less concerned than if, like around here when really cold there ends up with dry patches mixed with the snow/ice spots.
I had a problem with mismatched tires on my 89 BII. Got it used and while all tires were the same "standard size" the front and rear were different. This caused a front to rear imbalance. When I had it in 4WD, even with snow on the road, unless very slippery, it would refuse to go strait. Just the salt and sand they put down on the roads around here would create enough traction. It would pull to the right and when I corrected to going strait it would then go to the left. If it was very slippery that was fine. It was essentially impossible to drive that in the mixed conditions I described above. It had to be very slippery. I didn't realize this was the tires at first. It wasn't until I got a new set on and the problem went away that I realized this. I hadn't ever changed any less than 4 at a time so never encountered that before.