Hi all
Is this normal or I moaning? My differential is noisy above 30 MPH and after 50 mph I will not hear it because of wind. I am not sure if there is too much ware or the fact that I am sitting really close to it hearing all the noise. Is there a remedy to this?

I had this on one of my cars... had the diff rebuilt with a new CW and PIN and made no difference.... You'll need to check any play in the drive shafts and prop too.
Be careful, you're about to open a can of expensive worms !!

Thanks for your reply you are right about rebuiding diff I have done this on a different built and made no difference. Is my only option a new one?

The Sierra diff I put in my MK Indy wasn't silent. I took the view that being solid mounted and with me sat right next to it I'd hear any slight noise from it. I covered some 3,000 miles before selling the car and neither I or the following owner had any issues with it. As above they're not cheap things to rebuild so be careful what you start. A 2nd hand one could be a cheaper solution if there really were an issue.

Mine has made a noise from day 1! 9 years on no louder I just make sure there's oil in it and don't worry about it.
If it goes pop i'll put another one in then.

[Edited on 16/11/16 by melly-g]

Thank you all for the replies, shall do.

I believe you can get some sort of diff quieting oil, I think there was some in my current quantum as the oil level was a but to full (from previous owner) and came out a thicker black. I would say IIRC that it was a bit quieter when it was in.

could be worth a try for you. I'd agree with all the above, I've done edging on 20k miles in my 3 kit cars and over time and I'd also agree that nothing has changed with the noise, so I doubt there is a problem with it.

With a diff keep in mind that they're usually mounted outside the vehicle body using rubber mounts to dampen noise and vibration. Certainly in my Indy the diff was solid mounted adjacent to my left bum cheek so you're bound to hear more noise from it.

I'd really be tempted to check for any play in the driveshafts, but otherwise live with it and see if it gets any worse over time/miles. One other thing to check would be the oil level - it's not impossible for it to have been low or have lost some oil. Not sure what the drain/refill/check procedure is, but a Sierra Haynes manual should have that detail for you.