Join Date: Mar 2008
My Motorhome: A Caravan of all things !!
Thanked 469 Times in 394 Posts
The purpose of a dual mass flywheel is to prevent premature failure of the drive train.
A modern diesel engine produces a lots of power peaks (multijet engines have FIVE fuel injections per power stroke, yes really) these peaks in power are transmitted down the drive train and, if not damped out, will soon knacker the gearbox. SO...... the makers fit a DMF, which is basically TWO flywheels, one inside the other, between the two are a set of hefty springs set radially (in line with the flywheels rotation) these springs absorb the peaks in power that would otherwise damage the gearbox.
They are not a cheap item (about £700 I think) the biggest single cause of failure is apparently excessive heat. This heat is generated by friction when the vehicle is held on the clutch on a gradient. Its takes VERY little time to build up vast amounts of heat by doing this. The heat gets into the springs and destroys the temper (springyness) of them. There is no cure, the ONLY remedy is (expensive) DMF replacement.
Moral of the tale is that you should only ever hold your Mh on the clutch alone MOMENTARILY and by that I mean one or two seconds ONLY !!! remember if you are holding it on the clutch you are attempting to stop something in the region of 3.5 -4.0 tons sliding down hill !!! That puts a HUGE amount of heat and wear onto/into your clutch.
ALWAYS ALWAYS ALWAYS USE YOUR HANDBRAKE, NEVER EVER EVER YOUR CLUTCH !!!!!!!!!!!!!!
From the description at the start of this thread its clutch slip.
I think there is a problem with comfortmatic gearboxes, drivers THINK they are a different kind of (torque converter style)fully automatic epicyclic gearbox (Google search will explain) which you can hold on the throttle on a gradient, when in fact they are actually a robotised fully manual gearbox with a standard friction clutch that is all operated for you, so if you hold it on a hill on the throttle you are actually slipping the clutch all the time, with inevitable consequences.
Its not the destination that matters.
It's who you share the journey with (even if it’s in a caravan!) I am very fortunate to have Mrs Plodd to share mine with