BMW X5 Transfer Case Sprocket Assembly

The friction and steel set (sprocket kit) are now in stock and ready to ship.

A common question we hear all the time is what is the difference between the transfer case in the early BMW X5 to the late ones.

From 1999 to about early 2003 the BMW X5 came with a case known as the NV125 which has a planetary gear and no electrical components. In 2003 there could have been one of three cases. The NV125 is clearly identified by the round red tag that indicated it is an NV125.

The the LWX-500 was produced for only a few months and is similar to the NV125. It has a planetary gear and no electrical components. This case does not have the distinctive NP round tag. Although very similar to the NV-125 there are part changes in the inside like the output shaft aka driven gear.

In the ATC-500 the planetary gear was replaced for a clutch pack (frictions and steels) and a shift motor (an electrical component). The clutch pack comes as an assembly known as the Drive Sprocket Kit.

The BMW X3 ATC-400 has the same set up as the ATC-500.

BMW X5 ATC-500 Transfer Case

The BMW X5 is on its third transfer case model. The first one was the New Venter 125, the second is the ATC500 and the latest one is the ATC700.

The NV125 is relatively a simple case to work on. It has three major bearings, three seals, a drive and driven sprocket, chain and other smaller parts.

The ATC500 on the other hand is a bit more complex. Unlike its predecessor it replaced the planetary gear with a clutch pack and contains a pump and a shift motor. This unit was introduced in late 2003; around October of '03.

If you are not sure which case you have you can simply go to the case and check for the transfer case shift motor. There are other exterior difference but this is the most obvious.

Internally you already know about the planet and clutch pack as well as the pump. You can also look at the chain. The chain has one blue link for the NV125 and two blue links for the ATC500.

The ATC-500 also has four instead of three major bearings and two plastic dust covers (the other having only one metal dust cover).

More information will be coming for the ATC700 as it comes in. Stay tuned!










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