Np243c Transfer Case Chain

[dwbrune]

Does the chain in a np243c transfer case only drive the front axle?

[2COR517]

Yes. And it is only turning when you are in 4wd. Why do you ask?

[dwbrune]

 I've been hearing some intermittent clicking in the driveline while pulling up hills in 2wd. First I thought the transfer case chain may be jumping since the truck has 240xxx miles on it. Since the chain only drives the front axle the u-joints are now suspect. The u-joints have a little play in them but not a lot. Before I replace them I think I'm going to pump some grease into them since I put greasable u-joints in about 100xxx miles ago. I usually grease them every 10xxx miles or so but lately I haven't.

[jerseymike68]

Thanks for these information

[2COR517]

Any play in u-joints is too much. If the grease fixes it, it will be short lived. What brand did you put in that lasted 100K?

[dwbrune]

 I agree that the grease-fix will be short lived. I'm only diagnosing at this point. The joints are NAPA brand and don't really seem to have much play in them at all. Since I just greased them last night and about to take the truck on a 30 mile trip I'll definitely be listening for the clicking.  

[Spurshot]

Is the 243 case a fully manual lever shift type? My 99 2500's 241 turns the front driveshaft all the time, just from the internal drag of the clutchpack in the TC. That means the chain is turning. They can get loose enough to contact the case. Also, the TC oil pump has a habit of wearing a small hole in the case when a little clip fails.

[dwbrune]

The 243c is a push button version TC where an electric motor engages the front driveshaft when needed. When the TC is in 2WD the front shaft spins freely. Thanks for the info.