Is my diff going out?
 

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 shits 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.:vash: )

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. :bigtu:

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 :)

Yeah... I'll make sure to do them in the driveway so I don't have to push it far when something grenades.

STravisVrooman, I'm pretty sure most people here know that it's the smaller 6 inch R+P that is weak point and that we upgrade to the larger 7 inch.

I'll be waiting for a deal to come around on a 4.10 Torsen swap so if any of you see one for 750 or less, a PM would be appreciated. :)

I just dipped my finger into the differential fluid after driving around the block. No metal flecks.

thats what she said......

my transmission makes a hell of a lot of noise so don't count that out just yet

Like I posted earlier, I have the same sound. No problems and I don't even have a turbo.

A reply I recieved over at m.net about 6 months ago, when I asked the same thing about that siren sound. In repeated threads, synchronizer cones were always mentioned:

Driving issues. That noise is the gears/synchronizer cones in the trans spinning up to speed. Rev match your downshifts and you won't hear it anymore, but FWIW the noise is harmless. Not rev matching your downshifts wears out your clutch and, if done badly enough, can lock up your rear wheels and cause you to crash, especially if you do it in a corner.

Lol Kenzo, while what you describe is a valid source of noise (Yes I know what synchros spinning up to speed sounds like.) It is not the same. Mine makes this noise in any gear clutch in or out. Have you even watched the videos?

I rev-match every downshift. It's a habit and it's the only smooth way to do so with a lightweight flywheel.

Meh. Anyways I'd rather it be the tranny going out than the diff for some reason, just because it would be cheaper to replace immediately than doing a torsen swap. Tomorrow I'll check the tranny fluid level and for metal shavings.

I'm having second thoughts about not autocrossing it this weekend again. :)

Hokay, so my diff blew today. I got 7 runs in autocross with increasing noise near the end, made it 30 miles to within a mile of home on the freeway and then grindPOPgrindgrindgrind.

Ouch! That sucks!

I LUCKED out with my diff on Friday!
Made it from Kingwood to Clint's front bay-door before I heard the gears begin clunking. :bigtu:
When I got out of the car the entire rear of the car was coated in diff fluid... The under carriage didn't look too good either. :hahano:

aha i think im the only one with a good diff:) (Knock on wood) i spin my tires, drift if im bored, doughnuts, and spin my tires when i shift, and she has 160000kms on her:bigtu:

Haha yeah I've got an oily mess on the back of the car too. Miataz, you don't have a turbo, that's why your diff still works, though there's always a chance.

There wasn't any immediate warning that the diff was going to go. I put 300 miles on it with that whining sound and other than that, for thirty miles there was a tiny click on the transition between accel and decel.

Long-needed thread update:
I must have mechanical empathy. The carrier bearing failed. The ring and pinion looked to be in pristine condition.

I found a low mile 3.9 Torsen out of an 02 6 speed to put in. I love the Torsen!
The inside tire scratching for traction in the turns and in gravel parking lots, the feeling of the rear end being much more planted coming out of a turn and more predictable when it's not planted is just amazing.

Other than that, I've got a new noise in the transmission now that I'll post a video of sometime. I'm not too worried about it though because a transmission is a whole lot cheaper to replace than getting a Torsen swap.

nah. he just doesnt drive hard enough.

i blew the diff on my AE86 on a mountain drive.

and thats with a whopping 90 whp to the wheels. go figure.



get that thing fixed! the 7" rear ends will hold up well to the abuse.

ring gear howl. That bitch is toast.

Is the howl pitch sensitive to speed or rpm? (trans or rear)

Hustler, my diff is fixed, trans is making noise now. The whine changes with rpm. Sounds allot like the whirring noise in reverse except I get it in all gears.

The carrier bearing gutted itself when I pulled the driveshaft. Lots of exciting destruction of metal going on here.
Attachment 214365

R+P were still good sans where the Pinion gear was allot to push against the VLSD when the carrier bearing finally blew out. That was probably all done during the 200 foot grind to a halt on the highway.
Attachment 214366

So, what you're saying is you're sitting on a six speed you want to sell me for cheap?

Lol, I wish! Though if I had a 6 speed it'd be in the car ;)