For 6MT single disc dual mass flywheel CL, you have a few options.
1. Just replace the friction disc and re-use the flywheel and pressure basket.
If re-using the flywheel, you need to pay extra attention to any noise/feeling before removing the trans.
Unlike the twin disc CL, the torsion spring is inside the flywheel connecting the 1st and 2nd flywheel.
The springs are under continuous changes in load characteristic that they can fatigue and eventually break down.
This will result in judderly noise or you can feel the judder or abnormal vibration at the bite point.
As you never know what will happen in the long term future, if you covered well enough mileage with your existing 6MT CL, you may want replacing the flywheel and the pressure basket together with the friction disc at the time if, for some reason, you want staying with the single disc dual mass flywheel.
2. Replace all three.
As per above reason, replace all three together at the time of 6MT CL service.
3. Replace main shaft to Type-S Zero/NSX-R spec and use twin disc CL instead.
Because of the complex structure, as you found out, the dual mass flywheel is mega expensive.
To me, it’s actually reasonable price considering the small number of 6MT models produced and knowing the complicated design/structure.
So, at the time of 6MT CL service and if you need to replace the dual mass flywheel, my recommendation is to open the gbox, replace the main shaft to Type S-Zero/NSX-R spec and use the 5MT twin disc CL instead.
Better inertia distribution compared to dual mass flywheel, better eng response and price of mains shaft conversion is similar to replacing the dual mass flywheel.
If you have early model 6MT, you can convert the 5-6th synchro to double cone type at the same time.
So, for the first 6MT CL service, you may be able to re-use the flywheel and the pressure basket and just replace the friction disc.
On the second occasion when you are very likely to require replacing the dual mass flywheel, you may want considering the above option
#3 .
Of course, I'm assuming that you will be replacing other standard items at the time of CL service such as the bearing, release guide, release fork, etc so none of them are included in the above options.
Kaz
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