Diff noise issues
 

I have been doing a lot of searching, can't find this problem anywhere, or any real problems with the diff, so i shall ask..

Been having noises for a long time, been back and forth with Subaru trying to sort it out, they keep telling me its the axle nut, get the usual click click getting on and off the throttle, and reversing and going forward etc.
They have torqued it a lot, i have checked it myself and it's fine.

Anyway, noise has gotten worse.

I recently had some power by max subframe/diff solid riser mounts installed, while it was there my mechanic mentioned that there was a lot of slop in the diff.
over the last few weeks, the noise has moved up to a ticking sound, usually fine when the diff is cold, but when it warms up it gets louder (almost embarrassing to drive!)
First i thought it was an exhaust leak, had that sound to it, but it was speed dependant (not engine revs)
Also couldn't go over 80kph (50mph? I am an Aussie) without the back end vibrating heaps, which is even more evident with the solid mounts.

I have been back to Subaru, who said the diff is cactus, but don't want to replace it due to the solid mounts saying that was the cause (even though i have email records with them saying the diff issues were there prior to the mounts being installed.)

I have to wait till Monday to talk to the service manager who is off on holidays, I reckon I will have a good case to get it replaced, my suspension guy is a good mate of his, and one of the best in the country, and the mechanic works for him now and then and he does all his race cars.

But I am trying to work out what the tick tick tick noise could be? As i said, it happens when the diff gets hot, once its cooled down it goes away.

Also, I should mention, this has been going on for 2.5 years now.
I lowered the car a while ago, coilovers, PBM LCA's, Hardrace toe arms, then the diff risers cause the car is so low.
All so I wouldn't have any axle issues..

I had the same noise but I read somewhere on here that it was the ac compressor clutch or something like that. Try turning the AC off and see if the noise is still apparent. That worked for me just a thought. Still need to go to the dealer to fix it tho but meh...

check axles

Have checked the axles, the CV's are fine, have had them stripped down as i thought that was the problem to start with. :\

It's not that, and its the wrong end ;)

A problem with the diff from the factory is not far fetched. The factory uses crush sleeves on the pinion, they are a guessing game. I opened up a friends diff to find a bunch of writing inside that seemed to say someone had been in there adjusted after the factory. This diff was fine but he wanted a FD change.

Are the axles on the twins the same design as s2000? If so, look over on s2ki.com. The s2000 often has an axle "pitting" issue inside the cup of the axle.

Note: I was too lazy to go through the entire thread to read if you already tried that.

Worked out what the ticking noise was.
And makes me wonder how shit the Subaru mechanics are.. My mechanic spotted it straight away..

Cause of the PBM diff/subframe risers, the diff sits quite a lot higher now.
Driveshaft sits super close to the heat shield under the car, when the exhaust heats it up, it warps slightly making it rub against the drive shaft. .

Still have slop in the diff though.