Just saw the oil spots on my driveway yesterday. I pulled her into the street and looked up to see oil all over the front of the rear diff. 12k on the clock. Anybody have a similar problem?
DK

 

look clesely it is probably not from the dif. It is from the breather hose coming off the motor. You just noticed where it gets caught. I went the the local auto parts house and baught an 18" long piece of 3/4" hose rated for oil and a hose clamp and attached it to the pipe coming down from the motor so that it leakes a little closer to the ground so it doesn't get caught by the rear dif.

 

Sounds to me like the rear diff pinion seal is leaking. This is the seal that seals the yoke from the driveshaft to the rear diff internals. You could try cleaning the area and monitoring over the next few days to verify if it is or not as you still have quite a bit of warranty left. You may also want to check your fluid level in the diff to make sure it is not low as well (if it is the culprit of the leak).

 

Are these CTD's known for this? My PSD's pinion was leaking after 5k miles, it was a known problem with them. Took it in and had it back that afternoon.
DK

 

These are the stoutest rears out there if you ask me ,same as on Chevy trucks but with bigger axle tubes . 22,000 on mine now with no leaks at all only complaint are these unservicable u-joints !! NOT a common prob as far as I know . Just tool on down to the smiling DC dealer and let them take care of it on their dime . I would check all the fluids as some have been under and overfilled ,mine were perfect but worth checking into . Welcome to Cummins land that beast still amazes me everytime I tow and just sounds so sweet with a good intake and duals .