2003 Transfer Case Model

[squeasel]

Greetings All!
I am in need of replacing the Transfer Case Chain. In searching for the part I note that there may be two transfer case models used for MY 2003, LWC500 or ATC500 and they use different chains. I have a 2003 3.0i with automatic transmission. How can I find the transfer case model that is in the car? I noticed a "badge" on the back side of the case (red lettering on metal) and think I saw a number on the case, FWIW.

All help appreciated.

[David.X5]

They have model numbers stamped on the case or a metal tag. The ATC-500 will have an actuator visible on the outside (with wires going to it).

It's even possible you have a NV125

The LWC-500 just has "LWC" in the middle of some other numbers.

[squeasel]

much thanks ... i will check when the truck returns.

[upallnight]

Up to 10/2003 the Transfer case used was the NV125. Look at your production date on the door jamb.

[David.X5]

I think we've seen a fuzzy transition. The LWC were definitely mixed in with NV125 before 10/2003. best is to crawl under the vehicle and check.

[squeasel]

Thanks all. This is my understanding based on Cobra Transmissions page ... the NV125 is the model and the LWC/X and ATC are submodels. (see BMW X5 Transfer Case Parts : , Cobra Transmission).

In my case I have NV125 manufactured on 9/11/2002 with the cars build date just after. So I believe I have the "one blue link" chain which I equate to LWC/X 500 and not the 2 blue link chain associated with ATC.

Hopefully I will get to the chain replacement soon and know for sure.

[JCL]

Originally Posted by squeasel

Thanks all. This is my understanding based on Cobra Transmissions page ... the NV125 is the model and the LWC/X and ATC are submodels. (see BMW X5 Transfer Case Parts : , Cobra Transmission).

In my case I have NV125 manufactured on 9/11/2002 with the cars build date just after. So I believe I have the "one blue link" chain which I equate to LWC/X 500 and not the 2 blue link chain associated with ATC.

Hopefully I will get to the chain replacement soon and no for sure.

The NV125 is usually referred to as the transfer case model used in the first generation E53, up to late 2003. The ATC500 replaced it for the 2004 model year. ATC refers to Active Torque Control. It is usually referred to as X Drive. Output torque is managed via a servo motor mounted on the side of the transfer case. That is the easiest way to identify the ATC500.

RealOEM list 10/2003 as the end date for the NV125. The confusion with model years is because different countries have different rules for what a model year is. In North America we think about a September introduction for the following year, and sometimes earlier, but some countries go strictly by calendar year.

I looked at the Cobra web page. They state that both the NV125 and the ATC are Torque on Demand transfer cases. That is not true, in my opinion. The NV125 does not have clutch plates and has a fixed torque split. I guess as long as you demand 38/62 split front rear and don't want to ever change it, that would be torque on demand, but that isn't how Borg Warner defined it. Torque on demand is generally acknowledge to mean variable torque split. The Cobra page looks to be wrong.

[squeasel]

Much thanks JCL ... you have cleared up my understanding of the early X5 transfer case and X-drive. This is a case that, until this thread, I was getting a more confused as I read additional information. I would say that Cobra is slightly misleading, as is the majority of information I found. Again, thanks.