A potential customer called re clutch problems he has suffered with his Evo. 6 Tommi Makinen Edition – he has had 2 or 3 clutches in his E6 TM car this year (reckons he drove his E4 harder and never had any problems). Clutch the car came with didn’t last long, then he had a twin plate clutch fitted, which didn’t last 500 miles (he wasn’t sure what make). Then he fitted an organic or standard clutch himself – not sure if E4~6 230mm or E7~9 240mm and he couldn’t remember what flywheel he fitted, but despite that being OK initially it has now started slipping after just 4 months!
His car is only slightly modified, so you wouldn’t normally expect such severe problems. We were reluctant to just supply yet another clutch kit, suggesting that he must consider that the car may have other problems.
After speaking to the technical guys at our sister Company, Xtreme UK, we identified the key potential problems as follows:
- When installing a clutch you shouldn’t put grease on the release bearing, if you do it attracts dust from the friction material of the disc and then the grease/dust compound can get onto the disc and that accelerates wear/causes slip. (customer did admit he thinks he did this!)
- When cars have a HKS twin plate clutch fitted (the older GD types) the car needed an extension to pushrod, as it uses a special release bearing arrangement. If you then switch to a single plate, some people forget to remove HKS extension and that causes clutch to be under extra pressure
- If the Viscous Coupling in the transfer has problems and is leaking or weak, then again the clutch suffers excessive pressure.
So we quoted the customer on one of our MTX Hi-Torq Evo7 2 pc.clutch kits (240mm – 2 x versions rated to 500Nm or 600Nm, from £425-), new release bearing and a lightened flywheel. We also recommended that whoever fits the new clutch, they should also check the slave cylinder and release mechanisms, also take a look at the Viscous (which can be overhauled). Whilst the gearbox & transfer is out, it is worthwhile to look at the condition of the bearings and front LSD case bolts whilst the unit is stripped.
Despite being in Kent, he was determined to get the car up to Xtreme in the West Midlands, as one of the Nation’s top Evo specialists, to have the work done. Whilst fitting the clutch, he also decided to go for:
- Fit 4.11 final drive gears whilst gearbox out
- EcuTek – car could do with being properly mapped/set-up he reckoned
Co-ordSport are distributors of a range of performance parts, including OE Mitsubishi clutches as well as clutches from Exedy and Helix.