Diff whine with clutch engaged + axle seepage

[Laika]

Originally Posted by kodyo

What exactly are they calling spider gears here? Because there aren't any in our diffs.

Here is an exploded Torsen T2 diff:
http://wiki.r31skylineclub.com/image.../DiffFAQ_4.jpg
http://images.thesamba.com/vw/gallery/pix/483695.jpg

No spider gears there.

I doubt it's the ring/pinion gear.

Not saying it isn't the actual diff making noise, I just think they aren't using the right terms, which makes me leery that they can even rebuild one correctly.

So just the T1 torsen has spider gears? Hmmm...they ruled out ring/pinion gear by saying that since there's no noise going straight, it shouldn't be that.

Now I feel really uncomfortable about their ability to get this car on the road correctly...

What are the other gears in the T2 called?

Edit: By the way, the car makes the same noise from the same location (rear left) on left and right turns alike.

[kodyo]

Well, these are spider gears:


I don't think Torsen T1s have spider gears either, to be honest.
This is a T1:


This is a T2:


The center gear would be a sun gear and the outer gears would be planet gears, as far as I'm concerned. Maybe more specifically, it appears they are helical gears.

I'm not an expert, just a hobbiest, so take this for what it's worth. As someone who just rebuilt a diff and has to do it over again because I did it wrong, I can tell you first hand it can be tricky.

[gramicci101]

Open diffs use spider gears. I think the T2 uses a planetary gear system.

Edit: Wikipedia says T1 uses crossed axis helical gears, T2 uses parallel gears, and T3 uses planetary gears.

[ame="http://en.wikipedia.org/wiki/Torsen"]Torsen - Wikipedia, the free encyclopedia[/ame]

[kodyo]

As far as options, I don't know that you have many. I'd try to get a new diff if you don't trust them rebuilding the current one. If they can get an experience person to rebuild it, I wouldn't worry too much about it.

[strat61caster]

Originally Posted by HapaHaole

The repair manual states to use the specific LX oil , check the BRZ manual section AD-26. there has to be a reason for using the Additive version of the rear differential fluid.

I apologize about the clutch pack statement, I had a brain fart and was thinking of 06 my X-runner that has the mechanical limited slip, Wrong forum..

Subaru BRZ manual states the following with regards to "Oil type and viscosity" on a vehicle with an LSD:

Other gear oil that meets API GL-5 and SAE
75W-85 or GL-5 and SAE 75W-90 specifications

http://www.carsaddiction.com/article...nual/#download
(p. 415)

General consensus is that the LS type Motul 300 is not required. Some discussion on it here:

http://www.ft86club.com/forums/showthread.php?t=19218

[Poodles]

As a general rule, you don't "rebuild" a torsen, it's replaced. I'm going to assume that';s what they're going to do.

[Laika]

Originally Posted by Poodles

As a general rule, you don't "rebuild" a torsen, it's replaced. I'm going to assume that';s what they're going to do.

The more I think about it, the more I think they meant to say they are rebuilding the carrier...by replacing the torsen.

[kodyo]

Originally Posted by Laika

The more I think about it, the more I think they meant to say they are rebuilding the carrier...by replacing the torsen.

Ahh, makes more sense. Yeah, you should be fine.

If you're interested in knowing, the only tricky part is that you want to measure the backlash on the ring gear before swapping the diff. Then, when you put the new diff in (with the old ring gear), you want to match that backlash. Chances are, the current diff shims will work on the new diff, but you want to make sure. They'll also want to make sure the torque to rotate after reassembly is within spec. That, and you want to keep the bearings with their original races, but that's kind of a given.

[Laika]

Update for anyone else with the issue in the future...

Dealership decided to forgo the "rebuild" and instead replaced the entire carrier. No more noise and not only that, I have immensely more grip during hard cornering. I thought my tires were the reason I was breaking loose every time I took a spirited turn but it looks like the differential was to blame.

The question remains: how does this happen?

[Poodles]

Originally Posted by Laika

Update for anyone else with the issue in the future...

Dealership decided to forgo the "rebuild" and instead replaced the entire carrier. No more noise and not only that, I have immensely more grip during hard cornering. I thought my tires were the reason I was breaking loose every time I took a spirited turn but it looks like the differential was to blame.

The question remains: how does this happen?

Honestly? Don't take it as a personal attack, but I've seen people beat on a car that is "at operating temps" because it idled to that temp. The diff is still dead cold and will have issues because of it.


I had a diff rebuilt years ago and the break in procedure was pretty intense and specific because of the heat treatment of the gears and how they have to wear in.


Or you simply got a defect. As the saying goes, "shit happens."

[Laika]

Originally Posted by Poodles

Honestly? Don't take it as a personal attack, but I've seen people beat on a car that is "at operating temps" because it idled to that temp. The diff is still dead cold and will have issues because of it.


I had a diff rebuilt years ago and the break in procedure was pretty intense and specific because of the heat treatment of the gears and how they have to wear in.


Or you simply got a defect. As the saying goes, "shit happens."

I would support that theory entirely. My "warm up" is usually idling till the needle gets to the cold line (6 o clock position), and then easy driving for ~7-10 minutes.

Is there anything else I could be doing to make sure my Diff isn't stone cold while hooning?

[Mikem53]

Sounds like you need a friction modifier additive for the diff. Some diff fluids allows the clutches to slip more than others. A friction modifier will help with the noise..

Originally Posted by Laika

My car has 35,800 miles and for the last ~1000 miles I've been hearing this differential whine sound when making low speed tight turns such as U turns or K turns. Or even maneuvering around a parking lot. I believe it sounds exactly like typical diff noise on these cars which is very faint but this is easily audible. I would consider it even loud because it can be heard over a conversation with the radio off.

The last time I changed the diff oil was at 32,000 miles and I used Motul Gear 300 as it meets the specifications per the owner manual and is supposed to be better than stock fill. Anyways, my first assumption was I did not fill the diff fluid properly. Today I had the chance to finally have the car in the air after not driving for two weeks because of worries. I checked the diff fluid, properly full, fluid looks good and smells as terrible as always. So I sealed the differential fill plug back up with a new crush gasket.

So the fluid isn't the issue. Makes sense because when making a tight turn in gear, I get the noise. As soon as I put it in neutral and keep the speed and turning radius constant, the noise is instantly gone.

Is it a bearing?

Also, while the car was in the air I got the opportunity to find that the boot on the driver's side axle closest to the differential is seeping grease. No tears in the boot but I think it's just not tight enough perhaps. I have no reason to believe these are related issues.

As of right now I have an appointment next week for Subaru to "look at it". I have a feeling I'm going to be told "that's how the differential is supposed to sound" which is a flat out lie and RE the axle, they'll probably just tighten up the clamp and ignore any missing grease.

Does the axle need to be replaced in this situation? It's lost a reasonable amount of grease just from what I can tell looking at where grease has landed on the underbody.

Any help is appreciated.

If relevant - my only modifications around this area are RCE springs, SPC LCA's, "aftermarket" diff fluid, Perrin shifter bushing and MTEC shifter springs.

[Poodles]

Originally Posted by Mikem53

Sounds like you need a friction modifier additive for the diff. Some diff fluids allows the clutches to slip more than others. A friction modifier will help with the noise..

We don't have clutches, though the friction modifier might cause the torsen to be smoother (spec is GL-5 as all GL-5 oils contain the friction modifier...)

[aagun]

i have same sound . i had drift event and weekend drifts . can you inform us what was worn in you diff ??