406oc.co.uk

Would you advice change from DMF to Single mass flywheel?

Sent from my Redmi 5 Plus using Tapatalk

A lot of conflicting advice on this one. The 90hp engine doesn't have one but it it the same as the 110? I have heard of people changing them with no problem but others that say it causes vibration, so the answer is I don't really know.

I have never had a DMF fail on a 406 - yet.

Peter

the purpose of the DMF is to protect the gearbox from the pulsing power strokes of the engine.

Six cyinder engines don't need them because there are more power strokes per cycle.

Normally, springs in the friction plate serve this prupose, but in high torque applications you can't fit big enough springs into the friction plate and so the dual mass flywheel was invented.

Solid conversions seem to be trouble free in the 110 hp 2.0 and 1.6 engines.

Solid conversions are reported on the 2.2 136, even when remapped to 180.

My 110 has had a solid flywheel for the last 50k miles with no issues what so ever.

They're fitted for a reason. As rwb says to absorb the torque pulsation. It may protect the gearbox, but my understanding is that the slower the engine turns, the harder they work. The most extreme condition occurs as the engine is starting or stopping, (hence combining a DMF with stop/start 'technology' is barmy & killed my lads 320 bmw). My research indicated the purpose oi the DMF flywheel and aux drive pulley was to prevent the crankshaft snapping.

In fairness I've not heard of anyone having problems with a solid flywheel conversion on a 406, but since a remapped 2.2 develops torque overload vibration when pulling hard I didn't want to chance it. Some owners have reported increased harshness after conversion.

The cost of a conversion is similar to a DMF + clutch kit and mine were both good for 150k plus, so you'll never see a saving on a 2nd clutch replacement in the future, unless it's a taxi.

Can't see an upside to swapping it myself.

+1 , on everything Doggy & RWB have said, there is no up side to the conversion
Only downsides

On a side note, if you wish to look after your D.M.F try not to drive bellow 1300rpm's in any given gear
Apart from pulling off from standstill obviously
People who pull off in second gear or drive along in fourth at 1000rpm's are prematurely killing there D.M.F

Good point

dirtydirtydiesel wrote: +1 , on everything Doggy & RWB have said, there is no up side to the conversion
Only downsides

On a side note, if you wish to look after your D.M.F try not to drive bellow 1300rpm's in any given gear
Apart from pulling off from standstill obviously
People who pull off in second gear or drive along in fourth at 1000rpm's are prematurely killing there D.M.F

Sent from my Redmi 5 Plus using Tapewormtalk

I appreciate RWB's explanation, never heard such a complete one before, that would then account for the fact that all the high powered BMW diesels have auto box's although you can get a manual in the petrol version.

Peter