Well I drove my first autocross yesterday.
I'm still on the stock 1.6 vlsd.

On the way home I noticed when decelerating from 45 to 20 there is a loud whining sound that decreases in pitch with speed. It seems to be coming from either the tranny or the diff. It makes this sound regardless of what gear its in and clutch in or out. Maybe I'll get a video or something.

Could my diff be on it's last leg?

 

i sort of have the same thing. Mines not loud but its a little whine like you said when you decelerate, i hope its nothing, it always does it when i down shift.

 

I already have increased whine due to the lightweight flywheel, but this sound is probably twice as loud as that.

 

1.6 diff going out is generally a "clunking" sound that increases gradually until you feel like your straight driving over speed bumps.

 

I had a similar whine for a couple days before my diff came apart and it wasn't even on a launch.

 

No assocoation with them, but if your diff is shot, or even if it is not

Tougefactory.com

has a great deal going on for a KAAZ 1.5 way diffs

 

I don't think that's going to help.

Anyway, I have the same sound in my 1.6. It sounds like a cop siren, so I stopped decelerating by downshifting. I just heel toe around corners now.

 

Turns, as much as I'd like one of those, I have no need for one and would settle with a Torsen swap.

Kenzo, The second part of your post doesn't make any sense. Heel + Toe downshifting means you're most likely decelerating in gear or downshifting on the highway to pass.

 

I used to downshift to slow down around a corner, w/ no use of brakes. I'd hear the whine.

I now use the brakes, downshift, and rev match. What doesn't make sense? Maybe I'm using wrong jargon?

 

That makes more sense Kenzo. I wouldn't ever downshift just to decelerate without also using the brakes.

Brake wear = $
Drivetrain wear = $$$$

I'm about to go take some video.

 

better formula:

brakes = for braking
transmission = for accelerating

 

I think it may be your diff. If you say that it still whines regardless of gear or clutch engagement, it's probly the diff since it is speed dependent. It may also be some final gear in the trans itself , but unlikely since the diffs on the 1.6's are the weak link.

Go get a torsen swap! It'll be better for auto-x anyways.

 

Ok now that I've video'd this noise to death...

I noticed it is quieter decelerating in neutral as in the last video.
Also in the first video I noticed my airbag light flashed near the end... WTF?

 

sounds like a supercharger! lol
only instead of making the sound when accelerating,
it does it while decelerating

 

its either the tranny or diff. let us know. do a few clutch dumps!

 

super quick way to diag your problem, Change your diff fluid. If its really shiny, like full of metal. your ***** probally gonna go.

 

I hate to tell you this Bryce, but it sounds exactly like my diff sounded a few days ago when it ran low on fluid (the shaft input seal was/is leaking. )

Didn't go away when I added fluid either.
On the plus side, now is a good time to upgrade to the 4.10 Torsen rear end.

 

I didn't know you were on here jeff! Yeah I just got raped by tuition so it looks like I'll be driving the Disco for awhile. :(
Torsen here I come!

Part of me wants to turn up the boost until it explodes, hehe.

 

The differential is rarely the problem, its the R & P that goes bad. One of mine sounded like that for a while before it moved on to the clunking sound. Upgrade to the Torsen.

 

Its your transmission, mine does it all the time when i down shift, i would get a video but cars in pieces. But I had no problems it just wines i really dont think its any problem at all. But i dont think mines that loud