Hi Guys,

I have a 03 JDM sti, and having finally got my clunking rear shocks sorted my front, rear or centre diff has started clunking now too on full lock when taking off or reversing into a parking space etc.

I never do donuts, and dont often slide the car even, bar recently at a track day, in the wet.

Anyone ever had a DCCD box repaired if it started clunking?
It does it now even in auto or with the diff set to fully open, or handbrake up 1 or 2 clicks.........
Any advice much appreciated

 

Has nobody else ever been through this??

Come on guys someone must have had one repaired...

 

I have the same with my hawk sti, but to be honest I don't worry about it, whether it will get worse and start clunking all the time I don't no, but if it's just when your on full lock I wouldn't worry. If I'm wrong I'm sure someone on here will say?

 

Right, so I'm not alone at least!

I recently did a track day, in the wet, and thought the understeer in low speed corners was un real!
Then thought about the clunking and thought maybe the fact the diff isn't as free as it should be was contributing to teh understeer also......

 

So in manual mode with the diff all the way back in the green, it still clunks?

Tony

 

Yep you got it.

 

Maybe the clunking could be coming from the rear (or front) LSD?
I get a **** load of noise coming from the rear diff on tight turns especially when accelerating and the rear diff will in effect be locked up.
That is on an 06 STI.

 

I have a MY04 Spec C with manual DCCD and on tight turns at low speeds and occasionally when reversing (DCCD at fully open position) the rear diff will sometimes make loud clunking noises.

I've been told that this is fairly normal and nothing to be concerned about.

Unless there is a problem...

 

Never noticed the agricultural (diff) noise in my previous MY05 STi Type UK.

My current RB320, from new has made the mentioned noise ONLY when reversing at very slow speed.
Dealer says its normal.

 

Hmmm....

Seems some say its "normal" and some dont.

I had a uk 05 sti previously also, and it was silent when manual an open or in auto.

I can't remember now if my jap 03 made noise when i got it, but i dont think it did........
Seems like its nothing to worry about too much anyway....unless i notice it get worse.

 

I have a JDM STi 2003 and on full lock it clunks. In reverse it clunks AND makes the clutch stink. All normal


If you think you're going to go round corners with the DCCD wound forward then you've got a bit of a surprise in store for you

 

Oh i know that alright!
But on fully open/back the fact it was still cluncking was making me think it isn't actually "opening" fully, causing the car to understeer as if the switch was wound forward.

Hey sure i dont even know if its the centre diff anyway! Could be front or rear, but sound more like its coming from under the seat, so front or centre are my hunch.

 

This is helpful...

http://www.youtube.com/watch?v=zHZSgXXC2x8

 

My uk sti my05 clunks also. Wouldn't worry.

 

My type R clunks, my Spec C doesnt, yet the diffs (Helicial?) are different I think, AP one on the Spec C? but it shouldnt make silly noises, have the diff oils been changed of late?

Tony

 

Funnily enough yes I have had the diff and gearbox oils changed recently with Motul synthetic gear oil 75w90 IIRC.

[Edit] it was Fuchs Titan 75w90 semi synthetic oil.

 

My jdm05 clunks a bit at low speed in auto will try fully open see what happens, thought it was normal though,

 

Motul Gear300? What did you use for the rear diff?

 

Strange.....It was shortly after having my gear an diff oils changed that I noticed it too....Had it done by an ex subaru dealer, more subaru enthusiasts really, they prep rally cars etc so Im sure they used the right stuff.
I did notice the gear change was a little smoother after it.

 

Sorry I don't know why I thought it was Motul , it was Fuchs Titan 75w90 semi synthetic, link as below.

http://www.opieoils.co.uk/p-973-fuch...eline-oil.aspx

Do you know which oil they used?

 

No not sure what they used.

He did say they only use whatever it is subaru recommended to them as it has "special polymers" which help keep gear change smooth and diffs working properly.......

Im not generally a gulable one when it comes to this sort of thing, so I hope I haven't been duped! I know different oils do have different polymers etc in them, what exactly they are I've no idea

 

My RB320 "clunks"only when im driving up into my garge which is quite steep,dont really know why it does itMaybe its the diff engageing & disengageing when i drop the clutch?

 

[QUOTE=Cannon Fodder;9578068]Sorry I don't know why I thought it was Motul , it was Fuchs Titan 75w90 semi synthetic, link as below.

http://www.opieoils.co.uk/p-973-fuch...eline-oil.aspx

QUOTE]

You used the same for the gearbox? How is the shift quality? Any reason why semi syn?

 

[quote=Suberman;9578622]The shift quality is fine, in fact it improved slightly after the oil change. Having said that when all the gearbox and diff oils were changed all the oils came out clean with no metal fragments on any of the magnetic plugs.

The only reason that I went for semi synthetic gear oil is that I change all the oils every 12 months and the specification would seem to be better or equivalent to the Subaru service guide.

My car will only cover 3000-4000 miles per year but I would rather over service the car rather than rigidly stick to the schedule in terms of time or mileage.

 

I believe the Spec C runs a clutch LSD? It needs an LSD specific oil?

I'm going to be changing the diff oil soon on my Spec C. I am considering Motul, but there isn't a LSD oil suitable for the rear diff with 75w-90 AFAIK.

 

my MY07 Spec C didn't like 75/90 in the rear. It's best with Silkolene BO90LS. Mine also didn't like Silkolene SilkTran Syn 5 in the Gearbox. I swopped it out to Castrol Syntrax.

 

I haven,t noticed any clunking on my 05 Jdm Sti. Steve.

 

I put Fuchs Titan Race SYN 5 75W-90 Fully Synthetic Gear Oil in my rear diff and it was simply awful. It felt like the rear end was going to tear itself to bits once the car got up to temp.
I checked out the workshop manual for the 06 STI with DCCD and it specifically recommended a 90 oil should be used in the rear.
I then went for Fuchs Titan Race Gear 90 LS High Performance Gear And Limited Slip Diff Oil and it is much better.

 

I think it's down to the LSD's. Have a MK2 Escort RS with an LSD and that thing bangs it's **** off on tight corners etc.

 

Dont worry about it my WR1 did this when on full lock, my current RB320 is even worse almost comical when reversing on full lock around a corner (kangaroo jumps) its normal for a rally diff to do this, some are worse than others!!! its a subaru trait!! try doing it with the diff locked makes the car snake lol!!!