Hit a pothole on the way home last night, and immediately afterwards I thought I had a flat tire, coasted a hundred feet and the noise went away.
Jacked up this morning, no damage that I can see. Sway bar links were replaced six months ago. With the vehicle jacked up, when I put a wrench on one of the front lug nuts and pull forwards, I can see the entire front differential move up and down, coming to rest on the skid plate. I am thinking the diff mounts are shot? The diff should not move like this? Thanks for any and all input...
IIRC you have much larger issues... I dont have one to go out and look at but even completely destroyed mounts wont give the diff enough slop to rest on the skid plate. Its like a bolt came out of one of the mounts.
That said the diff bushings and front mount are VERY VERY common failures especially with the hemi and the diesel engines (failure rates drop with the torque applications ). Commonly cause a clunking feeling and noise in the front end when you shift into drive or reverse or into neutral or park from a gear (quick loading and quick unloading of the diff).
Interesting. I can only see the one passenger side mount without removing the front skid. The bolt is there but it looks like the rubber is shot, as it is quite sloppy. Maybe I will pull off the skid and get a better look.
Removed the skid; the mount on the passenger side is totally destroyed. When you jack up the pumpkin, you can watch a lot of up and down movement on that mount. The front one seems good, not sure about the "hidden" mount, but when you jack it, all the movement seems concentrated on the passenger side, ie: it lifts and twists on that side. There are no bolts sheared, and the axle drops until to comes to rest on the upper inside section of the faulty mount. There is no damage on the inside of the skid, so it hasn't been "beating" off the plate.
With the weight off the damaged mount, I shoved a piece of rubber in the open gap, just to see if it would help until I can get it replaced. Sure is quiet now when Shifting from P to R or D or vice versa.
Had all three diff mounts replaced today. One trashed, the other two badly cracked.
Wow. No more front thumps and rattles over pavement faults. In conjunction with the sway bar bushings I replaced a few months ago, this thing rides like new again. Shifting from P to R or D and back is silent. Should have had these replaced a long time ago. I'm at 73,000 miles.