Drive Line chatter question

[Renegadezx]

So this spring I started to notice what I can only describe as gear chatter after down shifting. It goes into gear fine, but when I come off the throttle, it sounds like gears rattling like they did in old trucks before helical cut gears. It does this in all the lower gears, and probably 5th but not as loud. I'm thinking the diff, since it happens in all the gears and I've heard about pinion bearing pre-load causing whines when downshifting. I did pull the diff fill plug, and the oil has some fine metal in it, but nothing large. Tomorrow, I'll pull the pan and have a closer look at the bearings and gears.

Diff has gear oil with friction modifier and its out of a 95 mustang GT limited slip. About 70,000 miles on last oil change and 170,000 total.

Engine is 5.0 with 5 speed tranny from same 95 Mustang.

Has anyone had any experience with a similar noise under similar conditions?

Thanks,

[CraigS]

AT what engine RPM. I ask because most are fine on decel, but once below maybe 1100-1300, depending on cam etc, you can get into a situation where the engine isn't quite happy and so the drive line kind of bounces around trying to figure if it is in decel or accel mode. So the gears rattle. Otherwise, at 170,000 miles I think I'd be planning on a possible total diff rebuild. Are you happy w/ your gear ratio?

[Renegadezx]

I'm familiar with the chatter at low speed, but this just started at higher RPM and in all gears regardless of speed. The car gets good fuel mileage and we enjoy driving it the way it is, so I don't think I would change the ratio.