Yea thats what I should do! I have owned about 25 4WD vehicles over the last 35 years and don't need 4WD or AWD on the pavement. I hate having the front end turning when its not neccessary. All it does is cause excess wear on the tires and front end, not to mention power and gas mileage suffers.

 

Just so no one is confused...

pulling the fuse, or installing a switch will have absolutely no effect on milage, or normal wear and tear of cv joints, axles or anything else.
(except for maybe the transfer case as it will NOT be able to engage, at all)

When in normal A4WD, (automatic 4 wheel drive) and the computer senses the rear tires SLIP, it automatically engages 4WD. Such as on dirt, if you floor it, the rear tires will spin for a split second before the transfer case automatically engages 4WD.

But unless your burning out all over the place, the truck is ONLY DRIVEN BY THE REAR TIRES. Pulling the fuse or installing a switch is only good for being able to spin the rear tires (for fun) when you want to be able to. Thats it.

 

Yea, you are right, I pretty much figured that out!

 

Not really. Your front end is free wheeling most of the time as the truck doesn't put power to the front wheels unless it detects slippage.

 

It's still causing wear, because there are no "hubs" on these vehicles and the front wheels are causing the front axle, differential and driveline to turn any time you're moving.

 

This is definately some good reading :thumbup:
I have a question that I'm sure somoene has the answer too. I have the A4WD in my 02 EB Expy with the f/r air ride. I would like to purchase a lift kit but have not found a kit that is compatible. I've been told that the 4AWD function will cause vibration in the drivetrain. If I were to put the switch in to disable the 4AWD function would this prevent the front driveshaft from spinning therefore eliminating the vibration ?
Thanks in advance for any information..

 

Sadly, no. The front driveshaft is always mechanically connected to the front diff, and thus the halfshafts, and of course the wheels. That front driveshaft is always spinning when the truck is moving. The connect/disconnect point is always in the transfer case itself and nowhere else.

Rancho makes a good quality lift for our expos that is "only" 4-6 inches depending on torsion adjustment and I spoke to an installer that said that the Rancho never comes back with vibe issues.
The Fabtech lift is a true 6" bracket drop (meaning, at LEAST 6" with stock torsion adjustment..) and this angle is too great for the front driveshaft, and at highway speeds there will be vibration from the u-joints up there.

Not sure about the air suspension compatibility, but check the Rancho lift.
No vibe issues with the A4WD with this one.

 

Thanks for the info !!! Yeah I'm not sure about my options since I have the air ride.. I wonder if I were to completely remove the air components all together would the Rancho suspension work ??

 

The only reason I want to install the switch is so the A4WD wont engage when its just a little wet out, I would turn it on when its snowing and icy. What do you think?
In other words I want to control when the 4WD is on.
~Gage~

 

The air suspension and non air suspension mountings are completely different so the Rancho wouldn't work.

 

Makes sense.

Before I got new tires a couple weeks ago, my old (55K miles) BFG AT's had the worst traction I've ever experienced when the roads had any water on them. Thinking back, I've driven my Expy for well over 110K miles and never broken the tires loose on pavement before (Bridgestone Duelers and "newer" BFGs), but I could see where the electronically controlled transfer case locking and unlocking the front end would get old in a hurry. Thankfully I've had my 4wd switched off for quite some time.

 

Do any of you know if installing this switch can be done at the plug end of the switch (rather than using a fuse tap)? Also does the bypass turn on any warning lights on the dash?

 

No. Removing the fuse for placing it on a switch does not cause any warning lights.

I think several posters are confused by the logic here. Those of us with 1999-00 Expys have had a lot of problems with the AWD system choosing to go AWD when it doesn't need to. Mine does it accelerating up a grade. Usually the speed sensor in the transfer case is the culprit and simply needs to be replaced. However, sometimes there's something else going on with the computer control module. In order to get a normal highway ride the only answer is to remove power to the AWD control so it doesn't engage for no reason. The older Expys had this by default (97-98) on the dash. We're just doing it after-market. It will help your MPG slightly, but we're only taking 1-2mpg. Especially if like mine, yours was going AWD all the time. It shouldn't cause any problems since all you're doing to removing power to the electromagnetic clutch that engages power to the front wheels. In 97-98s in 2WD mode, they're running around like this anyway.

 

There is no electromagnetic clutch on the 98+ Expeditions. The front axle is always turning.

The only way you would get better fuel mileage would be if the truck was constantly in 4 wheel drive as both the front and rear axles are always spinning.

 

98? The disabling AWD mod is really only of use in 99s and up. Those like mine with only AWD, 4Hi, and 4Lo modes. Don't the 98s already have 2WD mode?