midichlorian

Hi all,

I have an 09 hatch STI, had it from new with no issues since I got it in March. Over the last couple of weeks it seems to have developed a problem when on full steering lock - in either direction at low speed manouvering

The tyres scrabble & it feels like the wheels are hopping. The diff control is in Auto, not locked. I've checked for any obstructions in the wheel bays & visible problems / failures on the front suspension & steering components. Nothing looks out of place - although the undertray does obscure a lot. Steering is free to move to lock both ways at rest, but as soon as the cars moving & I put on full or approaching full steering lock I get the problem.

Car is stock apart from prodrive 18" GT1's & Goodyear F1A's from new, Litchfield handling pack mod fitted in Sept (whiteline rear ARB & drop links, subframe bushes, front ALK & uprated PAS pump bushes), & most recently the auto-fold mirror relay sold by a member on here. I have heard of Whiteline issues on the ALK but I'm informed that Iain Litchfield uses the powerflex ALK.

Can anyone out there help with a diagnosis? Could this be a diff control fault or more likely alignment? Should I get the geo checked? The geo was done in Sept at Litchfield, but in October I went on the wet grip track at Rockingham & did have a couple of 'offs' onto the dry tarmac at sideways angles (at low speed of course).

Any help gratefully received - diagnosis at the dealer will undoubtably cost me a lot!

Thanks, Greg

scoobyboy

don't they still have a lsd up front as well as the rear? if so sounds like it's typical of how it works which is normal,

Beastie

iTrader: (2)

try putting the electronic diff to free i.e. all the way in the green.

Its the diffs fighting each other of full steering lock and is quite normal when set in Auto.

:-)

vulnax999

iTrader: (7)

Only the center diff is electronic, the front and rear ( I think ) are viscous coupling LSDs. Might be mechanical, but not user adjustable.

But on full lock all the suspension joints are at their limit and so there may be some play / jerking... and maybe some effect from the power steering system?


I see you have larger wheels / tyres, maybe dragging these around on lock causes the problem? Although the 330S comes with 18" wheels and it's fine on lock.


Dunno if that helped, maybe worth going back to the garage for a check over? Good luck.

midichlorian

Guys,

thanks for the replies.

having looked on IWSTI here,

VDC, DCCD, and SI-DRIVE Explained! (Great Info) - IWSTI.com: Subaru WRX STI Forums

it seems the front diff is a helical LSD, the centre is a mechanical LSD and the rear is a torsion electronic diff. With the centre diff controls fully open it still happens - so based on your advice it could be a tyre thing or something to do with the front diff?

I'll take it down to Prosport in Stockport at some point to get it checked out. It's not a huge issue but I wanted to be sure it wasn't something that could affect the cars handling at speed - I'm concluding not since it only happens at low speed manouvering at full steering lock & with the centre controls putting most of the torque to the back wheels.

Thanks again

dunx

iTrader: (3)

All LSD's have an effect at low speed on lock, the wheels are turning at different rates so the diff is trying to fight it, as it's designed to.

IMHO

dunx

P.S. When mine was newer, just reversing on full lock into the garage was and up & down affair.

midichlorian

Thanks Dunx - great to know it's not just my imagination

Pavlo

It's the DCCD having an effect, partially locked at low speed, high steering angle so you don't ditch it pulling out of a junction. During a tight turn, the front wheels travel further than the rears, so partial lock on the centre diff will show up.

greatgonzo

iTrader: (1)

Mine does this to 2006 STI when on full lock, but now I'm in the habit of just flicking it into full green mode (all the way back) and then its nice and smooth

Lofty91

I still can't figure out what setting to use and when just keep it in auto

Although i did try it on one of the orange settings while going down the
Neighbours gravel drive and it just skids a lot on the inside wheel.

cster

Even with the DCCD on green, I still get issues from the front diff on full steering lock.
Seems even more noticable in the cold weather for some reason.

greatgonzo

iTrader: (1)

don't sound right, maybe a visit to the main dealers?

Pavlo

Sounds right to me. Although "issues" isn't very specific, I would expect some noise and maybe even some skipping of the inside front wheel on full lock. When it's cold the diff will be tighter.

dunx

iTrader: (3)

A stiffer diff. and low friction at the tyres due to the weather will make it "feel" worse.

IMHO

dunx

Potiriadis

I noticed exactly this going up a multi storey car park on Saturday, the back wheels were scrubbing slightly as I turned up the ramps. I put it down to grunt vs grip vs diffs.
It felt exactly like driving my dad's old hi-lux with the dif lock engaged (apart from the truck/car, power, diesel/petrol, agriculture/road use issues).

MrNoisy

iTrader: (28)

I asked my local dealer in Twyford about it and was assured it's perfectly normal on full lock and is really nothing to worry about.
I only noticed it after I'd gone from 17's to 18's.