For anyone changing the clutch & flywheel on a Hawkeye WRX (not STi)

Apologies if all this is common knowledge but after speaking to a number of suppliers I found that there is a "knowledge gap" re: flywheel for Hawk.

I recently had the HGs replaced and whilst the engine was out I decided to have the clutch replaced (saves an expensive job further down the line) and fit a lightened flywheel at the same time.

So, Exedy Clutch kit and lightened steel flywheel was supplied by Aztec, the clutch was correctly listed for 2.5 Hawk and fits OK to the new flywheel, the flywheel was listed for "all 5 speed".

Result:- clutch slip in higher gears on standard power.

I won't bore you with what the relevant people from Aztec & Exedy said but after my own research I found that the Hawk O/E flywheel has the friction surface (where the clutch plate friction material actually does it's job) recessed by 2mm. The new lightened flywheel does not have the recess. So when the new clutch kit was fitted to the new flywheel the clutch cover diaphragm is pushed beyond it's optimum clamping position and allows the clutch to slip.


I had the original flywheel refitted with the new clutch (Many thanks to Andy @ Williams Motorsport and Graham @ EngineMapper) and everything is fine now.

An alternative solution would be to machine a recess into the new flywheel and refit it, well - maybe next time :-). Or, if buying again - I would go with the flat flywheel and Newage clutch kit (assuming crank to bearing distance is the same)

Cheers,

AJS

 

Hi Adrian,

Glad you got to the bottom of your problem.

Just to clarify, the flywheel was supplied on the basis that it was assumed to be incorrect and could be returned if not identical to the OEM flywheel coming off.

The product description has been clarified on our website.

Cheers,

 

But just to be clear everyone, this is not a dig at Aztec!!!

The offer of return was appreciated but the F/W was used for a few hundred miles so I don't expect you will want it back now


I just want prospective buyers to be aware of the difference between the flywheels so that they will be armed with more info to ask the right questions whoever their supplier is BEFORE buying.

BTW Bob, do you expect to stock a lightened F/W for the Hawk in the future?


Cheers,

AJS.

 

Cheers Adrian, I'm sure your info will help other hawkeye owners on a 5 speed box.

Will keep an eye out for a lightweight flywheel for 2005 onwards WRX, but I've not seen any on the market yet.

 

Thanks for the info, I will be looking for a clutch fairly soon and would have got the lighter fly wheel as well. I guess the only option is to get a new OE one to fit with the new clutch.

Arthur

 

Just skim your old one Arthur (if needed).

 

Thanks Bob.

 

An alternative combo for the Hawk would possibly be the 5 speed flywheel & newage clutch kit (rather than the Hawk clutch kit).

All it needs to prove that this is suitable would be for a supplier to compare the two clutch covers for overall height and that the clutch plate splines are the same.


Cheers,

AJS

 

Cheers for the info on this guys. My Hawk WRX will be needing a clutch and soon. I was hoping to do the flywheel too. I'll keep an eye out on Aztecs site to see if one becomes available.