2003 4.4 no awd

[Bull907]

I have a 2003 x5 4.4. I live in Alaska and I have no awd at all so it’s quite an issue. It has never worked (I’ve owned it for 8 months) and I have no idea what the issue is. Every thing else works perfectly. I was thinking it was the transfer case actuator however from my research and looking at it 00-03 do not have them. I’m not aware of any plug ins or anything else that would cause this. I don’t have any weird noises and as far as this issue it’s perfect.

Thank you very much to all who reply.

[Crowz]

I seem to remember there was a problem that even included a recall on the front drive shaft that runs from the transfer case to the front chunk stripping the teeth out on the end that goes into the transfer case.

Maybe someone with more knowledge of this one can chime in.

If that happened you wouldn't have any power to the front wheels.

[Bull907]

I’ve replaced my front drive shaft with the extra inch long spline. I don’t think it would be the issue...

[oldskewel]

Does your car have the NV125 transfer case?

When you say you have no AWD, can you expand on that? Do you have front wheel drive only, rear wheel drive only, no drive at all (car does not move), or something else?

If you have the NV125 (my 2001 3.0i does), that can be thought of as a differential with a 68%/32% torque split rear/front. Nothing but gears and bearings from the wheels to the AT, nothing fancy, easy to understand and hopefully troubleshoot.

[Bull907]

It does have a nv125. The rear wheels turn. Everything works perfect on the car it drives great but the front wheels have no power to them.

[Qsilver7]

I'm not sure if it's been made clear as to how you've determined that the AWD distribution to the front axle is not functioning. (This is not to say that it isn't...it just hasn't been made clear in what I've read so far).

Just to be clear...the early e53 X5 doesn't have xDrive...the 2000-03 models have an AWD version that is similar to early versions of BMWs used a decade before but with the addition of DSC. It is referred (rarely) as DSC-X. This DSC-X AWD/traction control system was replaced with xDrive starting with the 2004 X5 model year.

See the info below that explains this pre xDrive AWD systems...and take note of the information about ADB (automatic differential brake)...where ABS braking is applied to the front axle (if wheel slip is detected) and allows the rear axle to slip/spin:

[oldskewel]

Originally Posted by Bull907

It does have a nv125. The rear wheels turn. Everything works perfect on the car it drives great but the front wheels have no power to them.

Can you be more specific on why you think there is no power to the front? Spinning rear wheels throwing snow like a snowblower while the fronts just sit there? When stuck / when rolling? Something else?

It's a very simple system, as I mentioned above. If you know how a differential works, you can think of that NV125 transfer case as working just like that. The NV125 uses a planetary gearset which automatically produces a 68/32 torque split based on the radii of the rear/front contact points of the planetary gears.

As Qsilver7 provides in great detail, the smart part of the system then detects wheel slip (like ABS does, or traction control on a 2WD car) and modulates braking to the wheel that is slipping to stop the slip and allow torque to transfer to the other wheels that still have grip.

First thing I would do is to verify that everthing is good mechanically, so getting the wheels off the ground and confirming that things rotate as they should, coupling through the differentials and TC. If that all checks out, there may be something with the DSC.

Here's a good article that may help with the NV125 description. Sometimes some good pictures help a lot.
x5 transfer case tech article.pdf
EDIT - good article, but I now see that is not so much about the NV125. So look further if you want to see how the NV125 works.

[Bull907]

So. I know it’s not operating because I drive on snow and ice every day. When I am at a stand still I barley move while my rear wheels spin, when the Dsc is off. When I’m in deep snow I can clearly see that my front wheels have no power to them when the Dsc is off. I’ve almost gotten stuck in deep snow clearly seeing them not spin. When I go up steep inclines I can barley make it up because the rear will spin. My dsc works perfectly so it helps quite a bit but sometimes I have to turn it off to get up or out of things. Ive had people watch I’ve watched front tires never spin. I’ve gone over small snow mound and almost gotten stuck because I clearly have no power to the front tires. It drives identical to my 540i.

Everything else is in perfect working order as far as I can tell. I’ve taken all my wheels off and can’t see anything. I have two drive lines so I don’t see how it could only be 2wd

[Crowz]

Put it on jackstands and then shift to drive. One of the front tires should turn but the main thing you need to know is if the front driveshaft is turning. If it isn't then something stripped out in the transfer case or the chain broke. Isnt much else that could be wrong.

[Jeadiex5]

Mine was the yaw sensor located under the console. No power coming from it.

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