Well that makes sense then...a piece of wood (2x4) would not be well balanced.

I agree it is odd to have 2 drive shafts on different trucks that are basically the same size.

 

Is yours a 2x4?

 

'08 Screw - one piece

 

I have a 2010 3v 6 speed 2wd trailer tow XL regular cab 8' bed with a two piece drive shaft.
I ordered this truck and yes I almost cried when I saw the two piece shaft.

 

Yes it is....

 

Cant be.... 2 wheels driven by 4????

But it can be a 4X2... 4 Wheels driven by 2!!!

BTW.
My 2011 4X4 6.5 bed has a 2 piece. For who ever is keeping score.

 

my 79 f250 has dual shafts its just a long bed standard cab

 

It's totally determined by driveshaft length. Once they hit a certain length (for a given diameter), whirl becomes an issue so they use a carrier bearing and two sections. 4x2's don't have a transfer box so the length is longer in Screw 5.5' beds.

 

2012 Screw XLT, 5.5' bed 2wd.....2 piece drive shaft

 

2013 scab 6.5 ft box 4x4 1 piece shaft

 

My 85 F250 4X2 with 8' bed has two piece drive shaft, it also has a grease zerk on the slip yoke, no shudder issues.

 

2010 F-150 4x4 SCREW w/ 6.5 bed - 2 piece
2013 RAM 3500 4x4 CREW w/ 6.25 bed - 1 piece

 

my 2010 4x4 screw 5.5 had two piece shaft my 2012 screw 4x4 5.5 has a 1 piece

 

My '11, 2wd, Scab, 5.0L, 3.55 has the two-piece shaft. I actually had the slip/yoke clunk & roll out vibe that a lot of the EcoBoosters are saying they have/ had.

I got my dealer to replace my entire driveshaft & carrier bearing at about 12K and haven't felt the thunk when I roll to a stop or the take off vibe since that repair. I have 29K on the truck as I type this. *Edit* forgot to mention, my driveshaft was replaced with another two-piece unit.

 

A motorhome has what a top speed of 70? So I'm sure that the single shaft doesn't have the capability to get to speeds where inertia or vibrations are a factor into the safety and integrity of the vehicle.

IIRC as an example, eventhough the 3.7L V6 Mustangs with 300hp could easily do 150mph, but Ford governs them at a modest 105mph or so because the driveshaft was not designed or intended to spin faster than that. There are actually people on the Mustang boards that have removed the factory top speed limiter on their 3.7 V6 and had their driveshaft explode because of it.

Another interesting fact, my 2011 5.0L Scab 145" has a top speed of just 95 mph. I know this because I can hit the top speed if I mash the gas from the on ramp or entrance to most highways to the point it's merging onto the highway (Embarrassing I know) or go to pass someone on a two lane hwy and the truck will peg the fuel cut 1/2 way into the pass. I also know that the Screw, 4x4 EcoBoost I rented a year ago cut off 5 mph higher at 100 lol. I bet the difference in governors are due to one truck having the one piece shaft and the other having a two-piece.