Weird noise coming from the diff?

[criss]

It sounds like a bag of lose metal, but it only happen on certain rev range( around 3k) under heavy load, or lift off the throttle on higher rev range , it will go away when the clutch is not engage , but I'm quite sure it's nothing to do about the clutch.

Anyone have any clue about what it is ???

[toppertee]

Drain the the diff oil.
Noise can be a miss leading, I could of swore I blew the gear box in my Rx7. Only to pull it out and strip it, to find nothing wrong with it.
Diff oil, had a lovely chunks of metal in it.

I.E. check the easy stuff first.

[criss]

Diff oil had change not long ago and it seems ok.....
Is there any possibility that it's the worn out bearing ?

[toppertee]

Jack the car up.
Remove the stub axles, drive shaft. Drain the oil.
Remove the diff and have a look. It's really the only way to tell for sure. Removing the diff is easier than the gear box.
Bright side is the MX5 is bloody easy to work on.

[Mr Morlock]

If there is metal in the diff then something has failed. Diffs are a specialist area- just go to a transmission specialist and get them to check or listen for pointer on the problem. If unconvinced read a workshop manual and decide if you are prepared to take the work on and have the time and resources.

[criss]

Thanks for the advise guys , will jack it up when I have some spare time.

Looks like its running ok, but just the noise that bothers me a lot =[

[hks_kansei]

echoing Mr Morlock.

Take it to a shop if you're intending to open the diff.

Replacing a centre is not a home job, you need specialist equipment to correctly set the backlash etc for the Crown and Pinion.
If not set correctly, the diff may chew itself apart.