Ive been refraining from asking this question since I feel its a pretty simple one, but I just cant find an answer that totally makes sense in my mind...

So the predicament is, all of the fair priced trucks I am looking at, are 4x4's, BUT they have open diffs... My biggest concern would be at a wet boat ramp and not being able to get out, since my impression of open diffs is that it is essentially 1 wheel drive once traction is lost.

That being said, Im sure 1 powered wheel up front, and 1 powered wheel in the back would make for easier work to get out of the ramp, but it still irks me that its called FOUR wheel drive!

Anyone have experience with open diffs and boat ramps?
Thanks for humoring me

 

I thought those trucks with open diff had traction control, so the ABS applies the brake to the wheel that is spinning.


Hopefully an expert will be along and know for sure.

 

Thanks for saying the part I forgot!! Meant to say how influential the Adv Trac control is when slippin and slidin

 

4 wheel drive is better.

 

From a learning perspective, why?
I could see it being better by getting power to the steering wheels, but I could also see a locked rear end being able to "push" more, while the front end is "pulling"

 

I believe based on what I've been told, the front axle drive wheel on a 4x4 is the drivers side while the rear drive is the passenger side. Opposing corners working to push and pull. In 4hi, there's no speed limit and 4lo will give you amazing pulling power.

On a Ford locked axle, the axle will disengage at around 30 MPH whether the wheels are spinning endlessly or the vehicle is in motion. The open diff with traction control is proving to be pretty good, at least in my experience with my 2011 truck.

 

Do all the open axle trucks have the traction control? This is big for me because I'm looking (not ready to buy just yet) and I see a lot of open axle trucks that I like but would pass on because of the open axle. I'm not an off roader but I do get into the woods at times for firewood. I tend to keep my truck for a long time and I don't want to make an expensive mistake. I've always had limited slip but near as I can tell, they don't offer it anymore. Would an open axle truck be useless? I don't want to pose this question to a salesman because he'll just try to put me in the truck even if its something I don't want.

 

Traction control is a part of the Advance Trac system, and yes even the Raptor has it. Under heavy throttle the traction control gets in the way (throttle retardation, cut in power, etc), but in low speed situations with a touch of slip it actually works kinda well as long as you aren't so deep into the go-pedal to have the engine slice the RPMs.
My truck is 4wd, with an open rear 3.31 geared e-locker option and it's not failed me yet. I quite like the non-LSD rear end since Ford has been known for that clutch pack wearing, slipping and chattering a few years into ownership.

 

So, if I'm understanding this right, the traction control (which is on all open rear ends) is like the new limited slip only better. That would be great!

 

I've seen this topic hashed out many times on many forums.

I've owned both, and an open-diff 4x4 is going to be better in low traction situations than a locked-diff 4x2 any day of the week.

For one thing, you've got some power going to 4 wheels instead of only 2 when the wheels are not slipping, which reduces the chance of a wheel slipping to begin with. Secondly, you've got more weight on the front axle, so it increases traction on those tires. Third, you're spreading out your traction points so that you may have front tires on dry pavement when the rears are stuck or vise versa...more likely to have an axle that can grab. Fourth, instead of having the rear axle pushing the truck and pulling the boat, you've got the front axle helping pull it all. Physics says it's easier to pull than push.

And as mentioned, with today's traction systems, even open differentials can act like really good limited slips.

 

It may be a tad misleading, but the system is generically called 4 wheel drive because in a variety of traction situations, the drive power can be delivered to any 1 (or more) of the vehicle's 4 wheels. Traction (or lack of it) can determine which wheel delivers the driving force.

Traction control is intended to reduce the speed of a spinning tire relative to it's non-spinning counterpart. It doesn't redirect drive power. That's why the Raptor (and other models) have locking differentials (e or otherwise).


As for a boat ramp, your more likely to have the rears wet or on a slippery surface than the fronts (hopefully) which, in 4x4 will be able to pull up the ramp.

 

Thats pretty amazing technology! I appreciate all of the explanations guys, now I think it kinda sorta makes sense

 

Yes, great information here as usual. I didn't mean to hijack your thread but it pretty much kept on topic and helped both of us. I now know that I shouldn't fear the open rear axle. That opens up a whole new world of trucks that I really liked until I found out they had an open axle. I don't have a boat and it seems as though the e-locker is most used in that situation. Very helpful.

 

Exactly the same position im in!
Gotta love having a new reason to look at more trucks

 

I've always liked a good Limited-slip rear. My old 2006 truck was 2wd with a3.55:1/LSD and only the 4.2 V6 and it was a beast of a truck! In most weather conditions, that truck would go anywhere I pointed it! There was only one time in 10 years that it got stuck in the snow, and that's when I was trying to drive up the steep hill that I lived on steep hill during a blizzard, and had no room to get any momentum. It made it about 30 ft up the hill from my driveway and stopped.
My current truck is 4wd with the open axle, but with traction control. It does surprisingly well for itself in the snow! I have good All-Terrain tires on it right now (all I ever run) and I have not had to engage the 4wd yet for snow, knock on wood. However, once you switch it into 4wd, the computer turns off the Traction control.