I've noticed after driving my '03 Blob WRX' hard that there is a deep humming noise coming from the back of the car that goes once the car has been driven normally for a few miles, occasionally it makes the humming noise at the traffic lights when I don't have brakes applied and the car moves slightly due to a slight slope. Is it the diff or brakes? Kwikfit state it could be the propshaft after I popped in to see if the brakes were sticking.

Any ideas?

 

The humming/drone was only present whilst moving about 1mph before monday's remap, the extra power really seems to have made the noise present at faster speeds.

Anyone know how to check the diffs oil levels?

 

with the car parked flat you remove the top diff bung, when you fill them up you fill it until it comes out the top hole,
To know whats in it you could swap it, its a nats under a litre from memory,
Silkolene syntrax is the preferred fluid for most on here from what ive read.
hth

 

cheers, I'll fill it up in case.

Garages have just said wait for the noise to get worse before they can see to it as the car as been silent and the brakes haven't binded everytime I've taken it in so far.

 

I can't find a bung in the diff and don't know ho to access the top anyway!! I noticed last night at 30-40mph ish that tapping the brakes makes the noise stop, could it still be diff related?

 

You can see in the pic below that there are 2 plug nuts. The lower one is the drain plug and the one just off centre half way up the diff is the filler plug. You fill it through that 1 until it starts dripping oil out of it. About 0.8l.

 

Nice one, I was looking for a rubber bung! There is actually oil on the diff that doesn't drip so it's probably just been done?