4G Clutch vs 5G Clutch (Comparisons)
Posted: Tue May 08, 2012 4:43 pm
Originally posted on PUK on 20/03/2009:
I've compared both 4G and 5G clutches. The 4G clutch I had in my possession is manufactured by Exedy (disk = HCD015U & cover = HCC908) and it is now fitted to my 5G Prelude. The 5G clutches I had in my possession were a genuine original Honda 5G clutch (removed from my car) and a 5G clutch manufactured by Aisin. 4G and 5G clutches are interchangeable, however their part numbers do differ (including Exedy part numbers and Honda part numbers), which prompted my little investigation. I have spoken to Exedy UK and they have confirmed that the manufacture of their specific 5G clutch kit is outsourced to Aisin, so if you order a 5G specific clutch kit from Exedy, you will get an Aisin manufactured clutch. They told me that Aisin send the parts to Exedy in brown boxes then Exedy repackages them in Exedy boxes. The Exedy 5G clutch set (HCK2034) consists of disc = HCD303, cover HCC706 and a release bearing. I explained to Exedy that 4G and 5G clutches are interchangeable and they said that there must be a difference because if there was not, Exedy would have rationalised the Prelude range of clutches, which I suppose makes sense.
Anyway, here are the measurements (in CM & KG):
You can see that there is not a lot of difference. The surface area of the friction material is 3.1 cm on all, however, the 4G clutch has a larger diameter, therefore the surface area of the friction material covers a wider area, which must be an advantage. Another interesting point is with the weight difference. Clearly, the lighter 4G clutch has a performance advantage over the slightly heavier 5G clutches. When comparing the two, I get the impression that the Exedy branded 4G clutch does look like a better quality finished product that the Aisin 5G clutch.
The original 5G clutch bearing removed from my car is identical to the one supplied with the 4G Exedy clutch now fitted to my car (part number 55SCRN41P-6, manufactured by Nachi-fukikoshi). The clutch bearing supplied with the Aisin 5G clutch didn't seem as beefy and it didn't spin as freely as the other two either. But maybe it just needed some oil.
So, if anyone in the future is contemplating replacing their 5G clutch, bear this in mind - as the 4G clutch is both lighter and covers a wide surface area on the flywheel & clutch cover, I reckon it better than the 5G spec clutch. It is also cheaper to buy too.
I should also point out that the Exedy clutch is marked as Exedy on the parts themselves, along with their part numbers. However, the Aisin clutch has no markings and I did not purchase the 5G Aisin clutch set from a very reputable retailer, so there is a slight possibility that it might not actually be an Aisin clutch. It could be any clutch in an Aisin box and I wouldn't know (I'm in the process of claiming a refund).
Also, the Fidanza "8lb" aluminium flywheel actually weighs 8.4lb (3.8 kg) whereas the original Honda OE 5G flywheel weighs a hefty 18.3 lb (8.3 kg).
I've compared both 4G and 5G clutches. The 4G clutch I had in my possession is manufactured by Exedy (disk = HCD015U & cover = HCC908) and it is now fitted to my 5G Prelude. The 5G clutches I had in my possession were a genuine original Honda 5G clutch (removed from my car) and a 5G clutch manufactured by Aisin. 4G and 5G clutches are interchangeable, however their part numbers do differ (including Exedy part numbers and Honda part numbers), which prompted my little investigation. I have spoken to Exedy UK and they have confirmed that the manufacture of their specific 5G clutch kit is outsourced to Aisin, so if you order a 5G specific clutch kit from Exedy, you will get an Aisin manufactured clutch. They told me that Aisin send the parts to Exedy in brown boxes then Exedy repackages them in Exedy boxes. The Exedy 5G clutch set (HCK2034) consists of disc = HCD303, cover HCC706 and a release bearing. I explained to Exedy that 4G and 5G clutches are interchangeable and they said that there must be a difference because if there was not, Exedy would have rationalised the Prelude range of clutches, which I suppose makes sense.
Anyway, here are the measurements (in CM & KG):
Code: Select all
Diameter: Surface area: Weight:
Exedy 4G Disc 21.8 3.1 1.056
Aisin 5G Disc 21.2 3.1 1.157
Honda OE 5G Disc 21.2 3.1 1.167
Exedy 4G Cover 22.5 3.8 4.7
Aisin 5G Cover 22.4 3.7 5.3
Honda OE 5G Cover 22.6 3.9 5.1
The original 5G clutch bearing removed from my car is identical to the one supplied with the 4G Exedy clutch now fitted to my car (part number 55SCRN41P-6, manufactured by Nachi-fukikoshi). The clutch bearing supplied with the Aisin 5G clutch didn't seem as beefy and it didn't spin as freely as the other two either. But maybe it just needed some oil.
So, if anyone in the future is contemplating replacing their 5G clutch, bear this in mind - as the 4G clutch is both lighter and covers a wide surface area on the flywheel & clutch cover, I reckon it better than the 5G spec clutch. It is also cheaper to buy too.
I should also point out that the Exedy clutch is marked as Exedy on the parts themselves, along with their part numbers. However, the Aisin clutch has no markings and I did not purchase the 5G Aisin clutch set from a very reputable retailer, so there is a slight possibility that it might not actually be an Aisin clutch. It could be any clutch in an Aisin box and I wouldn't know (I'm in the process of claiming a refund).
Also, the Fidanza "8lb" aluminium flywheel actually weighs 8.4lb (3.8 kg) whereas the original Honda OE 5G flywheel weighs a hefty 18.3 lb (8.3 kg).
