Differential noise over bumps

[sharkrat]

Advice please!!! 2008 Mustang GT. I get a loud tapping sound every time I hit a bump coming from my rear end. Upon examination I could reproduce the sound by sliding the axle in and out as it has about 1/4" play. It was coming from the diff. When I opened the diff I could see that the axle was sliding in and out and tapping against the center pinion shaft causing my tapping sound. When I removed the pinion shaft, I could see evidence of tapping as there was some wearing. It is almost as if the axle is too long. I don't have a clue how to remedy this so any advice would be appreciated.

 

[Bullitt347]

Normal.
There is always clearance for these things. Some are tighter, some are looser.
You could try a new "C" clip. Measure the old one and measure a new one. Maybe the new one is a few thou thicker.
I suppose that the "C" clip groove in the axle shaft is worn, but not likely and the "C" clip is a softer metal.
I question your 1/4" measurement. Is that a guess, or did you put a dial indicator on the axle shaft and measure total movement?

 

[sharkrat]

Thanks for they reply.
1. 1/4" is too much but it is in 1/8" range.
2. Great call on the new c clips. I will order some and try that.
3. I agree the play is normal but it should not be so much that it taps when driving.
4. Also there is an o-ring in the axle groove. that could be worn and compressed.