Clutch change and Dual Mass Flywheel

[aspire_helen]

2001 C5 2.2HDi DW12TED4 engine, BVM ML5T gearbox (also Peugeot 406).
After 190,000miles and 21 years, some of the gears are becoming a bit difficult to select. I am going to give Le B'std its first gearbox oil change, but I am investigating replacing the clutch. Haynes C5 and 406 manuals give the procedure for replacing the clutch on axle stands, so if it comes to it I may give it a go on the drive.
At that mileage I suspect the Dual Mass Flywheel (DMF) would do with changing at the same time. BUT, a new DMF may be an unnecessary expense. Now I am retired, I only drive some 5000miles a year, mainly on motorways, and rarely stop/start traffic. In addition, I am a boring, steady driver!! As I understand the DMF is designed to smooth out rough driving on high torque engines, I think a solid flywheel will do for me and the balance of the car's life!
Regarding manufacturer, Luk seem to have a good reputation for clutch/transmission parts. Has anyone any advice or experience?

[myglaren]

Disappointingly I have recently heard that LUK is pretty much just a badge used by several suspect manufacturers, mainly Chinese and with very poor quality. Euro Crap Parts are well recognised for distributing such.

I can't verify this and a few years a go had a Lucas/LUK alternator fitted to my C5 and it was fine for the time I had it.
I did tell the garage never to fit anything from ECP and only use OEM or equivalent.

If it were me in your place I would have a new DMF fitted, although my driving habits reflect yours, in the main (also retired). Would plump for Valeo if available.

Ask at the dealer. Sometimes they have special 'deals' on for clutch/flywheel and other replacements that can be surprisingly good value.

[aspire_helen]

Just an update. I have driven about 2000 miles since changing the gearbox oil. The gear change difficulty has disappeared! All it needed was fresh oil. Citroen provide no schedule for oil change...its supposed to last the life of the car. Perhaps they didnt expect the C5 to last 20+ years?

[Armidillo]

Great that you tried the cheapest, easiest option first! Since we have much less rust problems in Australia than you, we can easily keep cars running for 20+ years - I have several of that age (Pugs and Citroens). Changing gearbox oil about every 100,000km or so is a no-brainer as part of maintenance for the older car (I have a couple that have done around 350,000km) - more often for the autos of course!

The 'sealed for life' myth (perpetrated by PSA marketing) has caused the premature crushing of many PSA cars in Australia, and of course the trashing of the brands' reputation over here.

I use Castrol VMX with a shot of PTFE additive for smooth cold shifting. The PTFE treatment used is Nulon Smooth Shift, but I'm sure you must have a local equivalent.

[MattBLancs]

Just for clarity, bit of copy and paste from where I have described it previously

Dual mass flywheel smooths the acceleration - deceleration - acceleration - deceleration speed changes of the crank. On a conventional solid flywheel, the clutch disk has springs which are there to do this smoothing.

Given the DMF is much better at smoothing, the clutch associated with a DMF is solid, no springs.

The engine speed changes are in-between each cylinder firing - so not something you avoid by driving style. Also the issue is effectively an unintended side effect of the power output of a modern diesel - this acceleration - deceleration - acceleration effect was always present but less of an issue as "the bangs were smaller" on a lower power output diesel.

Having said all that "gentle" driving can actually be more severe for a DMF: moving the car with engine at idle speed (which the engine itself is generally more than happy or capable of supporting) puts high load on the DMF internals. If you think about it, need to transmit torque through the DMF, but, with engine speed low the "time between each bang" is long, so the acceleration - deceleration effect is more severe. Engine speed higher, the engines own rotational inertia is helping keep the speed more constant.



Or short version, you could try a single mass flywheel, but I'd worry too much about it (albeit perhaps unnecessarily given lots of positive reports for single mass conversions!) So would probably stump up for another DMF.


Anyway, if gearbox oil was the answer even better! The stuff that came out of mine was grim! So made me feel better changing it even for placebo effect alone!