4X4 vs 4X2 fuel mileage

[joecrna]

Which TC is used in the 2004 with V6?

 

[daprez1963]

I too get 15-17 around town - 2005 v6 4x4 XLT. Even with the 265/75/16s. I was getting more like 17-18 with the stock tires. I baby it though, to get the most out of it.

I once switched to a wide tire for looks.....and then I went back in a few days and switched them back after I lost a few miles per gallon. wide tires will mean less mpg. stick with stock tires and forget about wide tires.....

 

[RetiredWrench]

I have had both 2wd and currently 4wd exp's....I got 15-17 in city on the 2wd and 14-16 on the 4wd one. i think you had other problems to begin with because 10-12 is definitely out of an average range for both. tire pressure, tune-ups, gas selection, a/c or not, weight loads, and driving styles have more to do with your mpgs then to simply disconnect items that were not meant to be disconnected. i would seriously rethink modifications such as that as it might lead to something unsafe in the future. while gas prices will make people try to find ways to improve mpgs, you might consider coasting to the next red light and save both gas and brakes instead of stepping on the gas and flying thru the intersection, missing other cars with the right a way...lol

As I stated, the sticking u joint on the front axle may have something to do with the poor mileage. The dealer looked at this vehicle several times and could not find anything wrong. "Disconnecting items that were not meant to be disconnected"? "Something unsafe in the future"? "Driving Styles"? "Stepping on the gas and flying thru the intersection"? I don't think so.

 

[Thelt]

I get 16-17 around town. If I thought I could get 21-22 by disconnecting the front drive shaft I would but I doubt it would actually do that.

 

[daprez1963]

I get 16-17 around town. If I thought I could get 21-22 by disconnecting the front drive shaft I would but I doubt it would actually do that.

I bet next he will suggest we disconnect our brakes to increase our MPGs....lol

 

[RetiredWrench]

You won't know for sure unless you try it. It would be interesting to see what results others get.

 

[RetiredWrench]

My next suggestion might be to keep "flying thru the intersection".

 

[Thelt]

You won't know for sure unless you try it. It would be interesting to see what results others get.

I are right but if 2wd Explorers are not getting much better than 16-17mpg...

 

[Uafan]

Say bye-bye to your transfer case..

 

[Curtis]

Say bye-bye to your transfer case..

Why would you say that?
There's no extra strain on it...
The auto 4x4 can still engage the clutches...

The only thing different is that the power stops at the output shaft instead of going to the drive shaft. If anything its easier on the transfer case because there will be 0 slippage on the clutches, less strain and less heat. I fail to see why it would lead to a untimely death of the transfer case.

 

[CDW6212R]

The issue could be the constant use of the clutches. They are not constant duty cycle parts. Just as the AC clutch would wear out faster if you engaged it constantly, the same could be happening in the TC.

 

[Uafan]

Why would you say that?
There's no extra strain on it...
The auto 4x4 can still engage the clutches...

The only thing different is that the power stops at the output shaft instead of going to the drive shaft. If anything its easier on the transfer case because there will be 0 slippage on the clutches, less strain and less heat. I fail to see why it would lead to a untimely death of the transfer case.

Coming from a Ford Tech:

"ask him what he thinks the zero load is gonna do to the viscous coupling, and that a bunch of ford techs thinks hes an idiot!"

 

[CDW6212R]

Coming from a Ford Tech:

"ask him what he thinks the zero load is gonna do to the viscous coupling, and that a bunch of ford techs thinks hes an idiot!"

Well given some expertise there, do you know if the electromagnetic clutch would be energized at all times with no front shaft? This is the BW4405 or BW4406 we are talking about, not the AWD BW4403/04/10 cases.

 

[Curtis]

Well given some expertise there, do you know if the electromagnetic clutch would be energized at all times with no front shaft? This is the BW4405 or BW4406 we are talking about, not the AWD BW4403/04/10 cases.

The only time the clutches should be engaged is with wheel spin. If your not "lighting it up" at every stop sign, the clutches should not engage any more than driving regularly with the shaft in place.

But then again I'm no Ford mechanic and I have no idea what a viscous coupling is.

 

[Curtis]

Just looked it up.

http://auto.howstuffworks.com/differential5.htm

Viscous Coupling
The viscous coupling is often found in all-wheel-drive vehicles. It is commonly used to link the back wheels to the front wheels so that when one set of wheels starts to slip, torque will be transferred to the other set.

The viscous coupling has two sets of plates inside a sealed housing that is filled with a thick fluid, as shown in below. One set of plates is connected to each output shaft. Under normal conditions, both sets of plates and the viscous fluid spin at the same speed. When one set of wheels tries to spin faster, perhaps because it is slipping, the set of plates corresponding to those wheels spins faster than the other. The viscous fluid, stuck between the plates, tries to catch up with the faster disks, dragging the slower disks along. This transfers more torque to the slower moving wheels -- the wheels that are not slipping.

When a car is turning, the difference in speed between the wheels is not as large as when one wheel is slipping. The faster the plates are spinning relative to each other, the more torque the viscous coupling transfers. The coupling does not interfere with turns because the amount of torque transferred during a turn is so small. However, this also highlights a disadvantage of the viscous coupling: No torque transfer will occur until a wheel actually starts slipping.


==
the site says that "No torque transfer will occur until a wheel actually starts slipping. " So if you drive it normally, you should have no problems.

But lets say you did do a burnout. The clutches engage, turn the output shaft of the transfer case and so what? There is no tension on the output shaft making it real easy for the clutches to remain at the same speed.

Not trying to be difficult, just trying to understand as I'm considering the brown wire mod and would like to know all the side effects before hand. Cause I will be tempted to do a burn out in the 4.6 with the posi.

 

[CDW6212R]

The original poster(OP) should have some feedback by now about his truck. I think if I yanked the front shaft, I would know for sure if the electromagnetic clutch was energized constantly or not. If it was, I would control that brown wire signal with a switch.

 

[joecrna]

There is no viscous clutch in this TC. It uses a ball ramp device (electromagnetic clutch). With no front drive shaft it will cycle constantly. The GEM thinks the rear wheels are slipping. Two sensors are located inside the TC.

 

[Curtis]

There is no viscous clutch in this TC. It uses a ball ramp device (electromagnetic clutch). With no front drive shaft it will cycle constantly. The GEM thinks the rear wheels are slipping. Two sensors are located inside the TC.

Sounds like you've been "inside" one of these.
In you opinion would this cycling cause excessive wear?

What do you think of the BWM, same effect? Or would there be no cycling?

 

[RetiredWrench]

There's always the possibility that I have something else wrong in the 4wd system. Possibly it's always engaged. I'm not recommending that others remove their driveshafts. I'm just reporting my results.

 

[joecrna]

Sorry so long to reply. I've been on vacation for a while. I've done the BWM on my own Ex. I don't use it much, just in case I need the extra power on dry pavement. I don't see how this would cause excessive wear in the TC. However many people say they have seen damage from this. Yes, I have been inside this TC several times. No, I can't find a reason using the BWM for prolonged periods would damage the TC. Still many people say they have seen the damage, so I can't recommend using it for very long. Not even for a few dyno runs or prolonged burnouts. Certainly not on a daily basis.