My 01.5 2500 has 244,000 miles on it, and I am hearing a metallic whirring when coasting to a stop, just before pushing in the clutch. Also on acceleration, when I release the clutch (it's a 6 speed), I hear a loud clunk if I release the pedal too fast.

The transmission and clutch were rebuilt/replaced in December 2011, and they seem to be working fine.

I inspected the driveshaft, and offhand I can't tell there is anything wrong with the u-joints or carrier bearing, though the rubber buffer pad in the carrier bearing has seen better days :-). This leaves the transfer case and/or rear axle under suspicion. The noises are occurring in town and on the highway, and I'm not using 4x4 so I wouldn't think it to be the transfer case.

I unbolted the driveshaft from the rear pinion yoke and raised the rear of the truck, and I notice there is what seems like significant play in the yoke before it engages the ring gear and starts turning the rear wheels. Could my dana 80 hybrid be going bad? Any other ideas what to check for the source of the whirring/clunking? thanks

 

Stuff does wear out, but I am thinkin u-joints first. Mine seemed tight but had a rusty dust all around the cups. When I dropped the rear shaft they were definitely crunchy.

Not sure on the backlash for the pinion, but I thought they should mesh pretty close with minimal play.

 

Thanks SIXSLUG - I'll take a closer look again at the u-joints.

 

There is a fair bit of play in all of the 80s especially with added mileage however in my experience the week link tends to be the carrier bearing or the splined end of the driveshafts into the carrier bearing. I had similar problems. After tearing it down was found that I barely had any splines left in there. Dana 80 is still solid 250k 500hp.

 

Thanks Weiercd - I hadn't checked that yet. I've been planning to do so for a while now since this problem has been so hard to diagnose, but I plan to run the truck down to the local Dodge dealer tomorrow to have them check over the u-joints and also I'll ask them to check the carrier bearing and if necessary the driveshaft splines.

It's good to hear your Dana 80 is still going strong with 250k.

 

Not a problem. If at all possible see if you have a local drivetrain shop. I found one near me and I will gladly take their word over dealer any day. Unless of course you have a good dealer nearby. Either way best of luck. Let me know what Happens