I have an 02 reg Type UK STi with PPP that has developed a 'knock' from the area of the rear diff. This occurs mainly when loading and unloading the drivetrain (almost accerelator on and off) and is fairly quiet.

When looked at during service I was told it was a problem with the tension in the rear diff and that it would not cause any damage and would need the diff and driveshafts removed to rectify. Other matters intervened and this has not been done (and the car is now out of warranty!!).

The oil has been changed in the diff which seemed to cure the knock for a while but it has returned. There are no visible leaks that I can see.

Has anyone had a similar experience that could offer any advice please?

Cheers
Simon

 

Nobody had a similar experience that could offer any advice please? Bttt for another viewing!!

Cheers
Simon

 

Simon, It will be slack in either the crown wheel and pinion adjustment OR the diff planet set itself. It could possibly be slack in the drive shaft to knuckle joint too but that is the least likely in my opinion. If it doesn't whine on drive or overrun then planet set is a good guess - blind!

I'd like to hear it to make an assessment to offer a proper opinion and if you wanted to pop down to us, close to Jnc 12 of the M40 we'd be happy to try to help. No obligation.

Good Luck David APi Engines / APi Impreza
www.apiengines.com

 

Simon, How many miles has your STi done? I noticed my 02 STi with 55k miles started making that exact same noise last week. It almost sounds like the knock (but not as loud) that the hand brake makes when it releases. Mine only seems to do it when I lightly accelerate?

 

David,

Thanks for the reply and the offer to take a look (which I may well take you up on!).

I have an appointment with my dealer about the safety recall from Subaru so I am planning to discuss this with them. If it is the planet set, are we talking big bucks to sort it out or not? What sort of other damage could it be doing while it remains like this?

SWAussie, the car has done 36.5k.

Cheers
Simon

 

I've got a MY02 STI Type UK. EXACTLY the same problem has started over the last few weeks. Car has done 82k miles.

What sort of cost is involved in getting a new / refurb one ?

And what's the score with 'uprated' diffs.

I'm running around 400bhp.

 

Are you SURE that it is the rear diff that makes the noise?
The rear inverted struts are known to be a weak link on the STI, when faulty they also "knock".

 

yep, its been confirmed as the diff. new one on order

not the struts, I got rid of those crappy subaru ones for AST's some while ago.