Replacement flywheel - dual mass or solid?

[JulianHJ]

I have a '56 plate Focus TDCI and the clutch is showing signs of slipping at full throttle. The car is just approaching 95k on the clock. The dual mass flywheel will also need replacing, as it's beginning to judder noticeably when switching the engine off.

The local main dealer is quoting over £1300 to replace. The local Halfords Autocentre is quoting £799 using Valeo parts (OEM, they say) or £699 for a solid conversion (also Valeo, I think). The chap at Halfords was singing the praises of the solid kit, stating that he's an ex-Ford main dealer mechanic and has fitted loads to Fords in the past.

Does anyone have any experience of solid flywheel conversions, and are there any negatives?

[xRIEx]

AIUI, a dual mass flywheel is used to reduce vibration; therefore, logic suggests that replacing it with a SMF will increase vibration (and possibly noise and harshness). Clutch operation may be harsher too.

By how much, I have no idea.

[Blanchimont]

Both places you've gone too will overcharge. Find a transmission specialist near you, call them for a quote.

I paid £580 for a DMF, CSC and a clutch a year ago and I only paid £580.

[FraMac]

xRIEx said:

AIUI, a dual mass flywheel is used to reduce vibration; therefore, logic suggests that replacing it with a SMF will increase vibration (and possibly noise and harshness). Clutch operation may be harsher too.

By how much, I have no idea.

^^^^^

This. It's a bit lumpier than dmf but liveable withable.

[chryslerben]

Blanchimont said:

Both places you've gone too will charge their going rate

Edited for accuracy

[Blanchimont]

chryslerben said:

Blanchimont said:

Both places you've gone too will charge their going rate

Edited for accuracy

which, IMO, is OTT.

[robdcfc]

Blanchimont said:

chryslerben said:

Blanchimont said:

Both places you've gone too will charge their going rate

Edited for accuracy

which, IMO, is OTT.

Because you know their overheads and profit margin?

I get people all the time telling me I charge too much but then again Im still busy!!

[chryslerben]

Blanchimont said:

which, IMO, is OTT.

I've seen both sides of the coin so can understand your view point.

[Blanchimont]

robdcfc said:

Blanchimont said:

chryslerben said:

Blanchimont said:

Both places you've gone too will charge their going rate

Edited for accuracy

which, IMO, is OTT.

Because you know their overheads and profit margin?

I get people all the time telling me I charge too much but then again Im still busy!!

Ok, then how can a specialist charge me £580 for a clutch, DMF and concentric slave cylinder for a car that only has 1500 on the roads (so rarer than the focus OP has) and that was using LUK parts.

That's what I'm thinking. Unless their overheads are huge, which of course I do not know.

[GroundEffect]

DMFs are to allow engines to run at lower rpm without causing all sorts of torsionals in to the transmission creating NVH and durability issues.

It'll rattle like a bag of bolts with an SMF.

[xRIEx]

GroundEffect said:

DMFs are to allow engines to run at lower rpm without causing all sorts of torsionals in to the transmission creating NVH and durability issues.

It'll rattle like a bag of bolts with an SMF.

Would it possibly cause damage to the transmission, or is it just unpleasant NVH?

[anonymous-user]

I don't think it'll do any part of the drivetrain any favours, you're putting a ton of vibration back into the system which was deliberately designed out by the use of a DMF. It can only increase stress on other components which weren't designed to deal with those vibrations. It might all be fine, it might not.

[Feirny]

Blanchimont said:

Ok, then how can a specialist charge me £580 for a clutch, DMF and concentric slave cylinder for a car that only has 1500 on the roads (so rarer than the focus OP has) and that was using LUK parts.

That's what I'm thinking. Unless their overheads are huge, which of course I do not know.

Have you thought about how much each specialist buys the parts in for, and the amount of profit they want to make?

I bet your car shares these components with some other cars on the road.

[stavers]

xRIEx said:

GroundEffect said:

DMFs are to allow engines to run at lower rpm without causing all sorts of torsionals in to the transmission creating NVH and durability issues.

It'll rattle like a bag of bolts with an SMF.

Would it possibly cause damage to the transmission, or is it just unpleasant NVH?

There is a very strong possibility that it will cause damage to the transmission. The DMF is not there just to remove unpleasant NVH - it also smooths the torque flow from the engine to the gear by absorbing the peaks seen as each cylinder fires. By removing the DMF you are putting the shock loading in to the gearbox.

If you only plan to keep the car for a few thousand miles, the SMF would be OK. If, however, you plan to keep the car for longer then the DMF is certainly the way to go.

I have heard of Mondeos going to SMF and then lunching gearboxes within 20k.

[addz86]

We sell both at work, clutch and flywheel in LUK which is what will have been put it from factory is about £400, I try and avoid selling solid flywheel kits as they're all stty Chinese copies and have heard of a few causing snapped cranks due to excessive vibrations.

If it was half the price and a old nail then maybe but £100 difference on a decent car I wouldn't even think of using one

[JulianHJ]

I wasn't that keen on the idea of a SMF, but the chap I spoke to seemed really keen, even though it would cost £100 less. I've had another quote from the nearest Mr Clutch - £810 using either LUK or Sachs parts (DMF, not SMF).

[JulianHJ]

Blanchimont said:

Both places you've gone too will overcharge. Find a transmission specialist near you, call them for a quote.

I paid £580 for a DMF, CSC and a clutch a year ago and I only paid £580.

Having looked at the parts costs from ECP and GSF, I'm not sure I could do it myself for much less - no that I have the tools or experience! The Halfords quote includes 5.1 hours labour, and for 60% of the main dealer quote using the same parts, I was certainly leaning towards them. I've Googled transmission specialists for my area, but I've not found anything useful.

[JulianHJ]

addz86 said:

We sell both at work, clutch and flywheel in LUK which is what will have been put it from factory is about £400, I try and avoid selling solid flywheel kits as they're all stty Chinese copies and have heard of a few causing snapped cranks due to excessive vibrations.

If it was half the price and a old nail then maybe but £100 difference on a decent car I wouldn't even think of using one

Thanks, just missed this as I was typing my reply. I'm definitely going to stick with DMF. Is there any difference between LUK and Valeo in terms of quality?

The Halfords chap was keen to point out that the Valeo DMF would be brand new, and not a reconditioned part - that hadn't even crossed my mind.

[Fastdruid]

stavers said:

xRIEx said:

GroundEffect said:

DMFs are to allow engines to run at lower rpm without causing all sorts of torsionals in to the transmission creating NVH and durability issues.

It'll rattle like a bag of bolts with an SMF.

Would it possibly cause damage to the transmission, or is it just unpleasant NVH?

There is a very strong possibility that it will cause damage to the transmission. The DMF is not there just to remove unpleasant NVH - it also smooths the torque flow from the engine to the gear by absorbing the peaks seen as each cylinder fires. By removing the DMF you are putting the shock loading in to the gearbox.

If you only plan to keep the car for a few thousand miles, the SMF would be OK. If, however, you plan to keep the car for longer then the DMF is certainly the way to go.

I have heard of Mondeos going to SMF and then lunching gearboxes within 20k.

This. I have a friend who works for Ford (IIRC he's a diesel calibration engineer so knows what he's talking about) and his exact words were:

A Ford Engineer said:

It's not particularly to do with feel so much as NVH (gear rattle) and gear tooth stress.

If you have a DMF you can have a smaller (lighter, slicker, faster, cheaper) gearbox than if you don't.

The extrapolation of that is that Ford (et al) once they've fitted a DMF have gone down the cheaper gearbox route and so you would damage it.

[JulianHJ]

Cheers, I did think that if Ford had spent millions in R&D there would be a good reason not to deviate so far from such a key component - just wanted to check as the chap at the garage was really enthusiastic about the SMF.