IRS differential slop

[Malibu46pt]

I have the FFR IRS. There is a small amount of slop in the rear end. With the car jacked up the tire will rotate back and forth about 5 degrees freely. When driving when I let off the gas I can fuel and hear noise (slap) in the gears.
Is this normal?

[CraigS]

Pretty much yes. If your diff has the Torsen limited slip unit it has more slop than the clutch pack type. Can you convert you '5 degrees' to inches your hand moves when you rotate the tire please?

[John Ibele]

Just another data point. I have an Eaton Trutrac, so maybe a different story. But I have about 2" of play (outside tire surface) when I rotate a rear wheel. I also hear occasional clicks and mechanical noises from the rear when I'm modulating the throttle at low speed. On this unit I've been told both of these things are normal.

[edwardb]

I hear the Torsen diff in my Coupe clicking and clacking as I let up on the throttle etc. Also by all accounts normal. Talked about in the Mustang forums some. In all cases, these diffs are much close to the driver/passenger than they are in a DD. And without the same level of isolation and insulation.

[Malibu46pt]

The rotation is about 2”. Based on the replies it sounds as if this is normal.

[FLPBFoot]

The rotation is about 2”. Based on the replies it sounds as if this is normal.

2 inches? Wow, that seem very high. Mine moves 1/4 inch. I'd be interested if the other who say they have slop have 2 inch movement.