4x4 with Open Differential
 

Hi All - I have searched and could not find a topic on this.

History - I had a 2004 F250 Diesel FX4 (4WD) that had a locking differentials - I LOVED this truck until.......the $$$$ started racking up. I was done with Diesel engine Truck (crapped out) and I took to dealer and dumped it... Oh I mean I traded it for a 2014 3.5L AWD with 4x4 H/L. I wanted to get as far away from Diesel engines as I could so I was eager to go to a gas engine.

Not realizing and thinking that all 4x4s are the same, it has become apparent that they are not and thanks to the information on this forum - I come to realize that I have a somewhat different 4x4 than my past truck and it disturbs me.

My Rear Differential is a Type 27 with a 3.31 rear gears. So, from my understanding is that it is NOT a Limited Slip or has a Locking kit - it is a Open Differential and it has me totally preplexed in that I fell like I have a LIMP version of a 4x4.

I mostly pull a 5000# boat and it has done it okay, but looking to get a Travel Trailer in the near future.

Are there any positives to having my rig in its present configuration or should I add a LS Kit to it.

Thanks All.

You should be fine, we have been using open difs for ever without problems. If you were in the snow belt a LS might be in order but I don't know how much you get in San Antonio area. If you were and off roader it would be different also.

Since you are considering pulling it apart to put in a LS you should consider just installing a locker instead. Price difference may be minimal and since you've had one you don't need to hear about the performance differences.

Keep in mind. You said locking differentials. No front diff is a factory locking from Ford. Its only the back. Today a locking diff in the rear is not needed as much as it once was because of the traction control that applies a brake to the slipping wheel and all the power goes to the wheel with the most traction on todays new vehicles.

I don't know how traction control would apply power to the wheel with the most traction on an open dif truck. There's no way to shift power on an open dif. decrease power to the drive wheel yes but it can't apply power to the other side.

If the traction control is designed and working properly with an open differential, the power will go to the wheel thats 'not' spinning.
If both wheels are spinning say on ice, it'd be a crap shoot.
In certain situations like being hopelessly stuck in snow, turning off the traction control could help.

Wish Ford would incorporate a rear LSD differential on the F150s.
The locker is useful in some situations but is limited to around 23 mph where it disengages automatically.

If both wheels are spinning on ice. you already have the best traction available. The stability control controls the backing off of the throttle if stuck, not the tc. I have an e locker and with it off I spin both rear wheels on asphalt. .

Not according to the manual on my 13. From page 236.
PRINCIPLES OF OPERATION
The traction control system helps avoid drive wheel spin and loss of
traction.
If your vehicle begins to slide, the system applies the brakes to individual
wheels and, when needed, reduces engine power at the same time. If the
wheels spin when accelerating on slippery or loose surfaces, the system
reduces engine power in order to increase traction.
USING TRACTION CONTROL
In certain situations (for example, stuck in snow or mud), turning the
traction control off may be beneficial as this allows the wheels to spin
with full engine power.
Turn the traction control system off by pressing the
stability control button located on the center of the
instrument panel.

Someone is going to have to explain to me how power can be applied to a non driving wheel in a open dif vehicle. These trucks are not all wheel drive. Open dif means you have one driving wheel. Without a locker how is power applied to the non driving wheel through the differential? is there some type of gear engagement (automatic locker?)

Here's a quick video from Lexus explaining the basics of traction control. The principal is the same with Ford, GM, etc.

I regularly pull a 14ft enclosed trailer with my open diff 4x4. If it's a little wet or there's dirt or gravel on the road, I have to take off really easy to avoid spinning. I bought a Detroit TruTrac a couple of years ago, but never got around to putting it in. That might be an option for you.