It's an old Toyota pickup, my 72 Ford had a one piece driveshaft that was longer than this whole setup.....guess they had their reason but only times I've seen two piecers was for heavy duty hauling
That is likely at least in part because the trucks for heavy duty hauling have longer shafts. The Ford shaft you refer to likely weighs more than a two piece assembly would, and back in 72, Ford was less concerned about weight. More recently, Ford was the first to go with aluminum bodies on the F150. I should check to see if my newish one has a two part shaft. If it does, it would be in order to reduce the weight of the shaft setup while still avoiding shaft vibration issues.
In one of my older Tacoma's I had minor but to me annoying shaft vibration issues, but I can't recall if it was the two part shaft design. If it was not, more recent ones may have gone to the two piece in order to fix the problem that I had in mine.
Anyway, the issue of shaft vibration is more about shaft length and stiffness than horsepower, although horsepower requires, all else being equal, heavier shafts, and heavier shafts may suggest a two piece design if the extra weight does not produce the needed increase in stiffness.
All this was clarfied quite nicely during my boat problem. It has a one inch solid stainless steel drive shaft which operated for years perfectly at all rpms. Then I got the brilliant idea of installing a modern so call dripless shaft seal on the shaft. The seal design included a substantial stainless steel collar attached to the rotating shaft as part of the seal design. Installation of the collar put maybe 200-300g of extra weight in the middle of the shaft, while the shaft stiffness was not changed. After doing that the setup worked perfectly until about 3000 rpm, but if I operated higher than that, all hell would break loose once in a while. At higher rpms, the shaft would unpredictably develop shaft whip that was violent enough to feel through your feet anywhere in the 37 foot sailboat. I spent a lot of money chasing the issue down because initial analysis suggested that the vee drive or transmission was the fault. After spending on those possibilities, I eventually figured out what the problem was, removed the new dripless seal, re-installed the old one, and problem instantly solved.
More information than you needed I expect, but I do get carried away sometimes.
ppp
