DMF? What's the point?

Comfortably Numb · 27th March 2019, 17:40

So, as posted in Technical (with no response), the CDT, after 132kmiles, has developed clutch judder as you set off. Once on the move, or standing idling, totally vibration free, it's fine, pulls like a train, 80 over Shap, I even took it to the ton a couple of weeks back. But the judder has been getting harder to avoid. So today I phoned the ex- Rover dealer near me, and described the symptoms. DMF says he - I used to do quite a few. "Strange" thinks I, "the general opinion on the forum is that DMFs are not a problem on these, especially if the clutch hasn't been abused - which it hasn't. In my 45 years of driving, I've needed 3 new clutches in my cars , 2 of which expired while being driven by someone else (and no, I don't lend my cars so someone else can take the blame!) Anyway, I took it to my usual garage after work, and asked the mechanic "How do you tell whether your clutch judder is DMF or oil on it?". "I'll show you" says he. So he starts her up, pulls the handbrake full on, puts it into gear, and starts to let the clutch out, building up the power as it starts to bite, and over about 15 seconds, pulling harder on the handbrake as it tries to move, he finally gets the clutch to slip with the pedal apparently fully up., and strong smell of burning clutch, but not burning oil.
Nor did it seem to produce the judder I experience on normal take-off. "Your clutch is worn out"says he with a grin " So why does it judder? I've driven cars with worn clutches before, and they've been smooth up to the point where if you accelerate hard, it revs like an auto!" "DMF has room to slap about if the clutch is worn ". Can someone explain how this can be. Broken spring(s)? Why, if you never let the clutch out quickly? Driving home, I didn't floor it, but I accelerated fairly briskly in all 5 gears along the dual carriageway, and while the bite is right at the top, once engaged, it doesn't slip under acceleration. Oh and it's an un-modified 115bhp motor. I think I'll just run it till it does slip in normal driving, then get rid. It will never be worth the cost of repair, despite it's 2001 Connie spec and rust-free body.

bl52krz · 27th March 2019, 17:45

Could it be the tear drop at the rear of the gearbox?

HarryM1BYT · 27th March 2019, 18:14

Quote:

Originally Posted by Comfortably Numb

Nor did it seem to produce the judder I experience on normal take-off. "Your clutch is worn out"says he with a grin " So why does it judder? I've driven cars with worn clutches before, and they've been smooth up to the point where if you accelerate hard, it revs like an auto!" "DMF has room to slap about if the clutch is worn ". Can someone explain how this can be. Broken spring(s)? Why, if you never let the clutch out quickly? Driving home, I didn't floor it, but I accelerated fairly briskly in all 5 gears along the dual carriageway, and while the bite is right at the top, once engaged, it doesn't slip under acceleration.

Mmmm, was he touting for business by wrecking the clutch?

A worn out clutch does judder, your judder has another cause. Check the gearbox rear mount. Its a ten minute job, once the engine (under) cover is removed. Two bolts to remove, you then poke screwdriver through the middle of the large bush and try to twist it, to show up any splits in the rubber mount. If its split (it will be) it needs to be replaced.

There are several possibilities for replacement - original Rover mount, a poly-mount to replace the big end bush, a modified Mondeo mount.

Comfortably Numb · 27th March 2019, 19:15

Thanks, guys. I'm taking my van in to work tomorrow, and I'll get the car up on ramps at the weekend to check the gearbox rear mount. That will be a lot cheaper than the £800 + the 2 garages estimated for clutch and dmf replacement. Fingers crossed you have correctly identified the problem.

marinabrian · 27th March 2019, 20:58

Andrew fit the clutch yourself, it's not a bad job, to do it properly takes a little extra time as the subframe must be removed to do the job.

A three part clutch kit can be found HERE for a shade over £116.

Finally, I would never take the word of someone who deliberately wrecks what is left in terms of friction material by doing what he did to "demonstrate" DMF failure........what a complete moron

Brian

Comfortably Numb · 28th March 2019, 20:24

Thanks for the encouragement Brian. I was given a last-minute change of workplace , Brampton, Carlisle - a 70mile round trip instead of the 20 miles to Penrith and back. I decided to risk it with the Rover, instead of the slow and thirsty 4x4. Needless to say, apart from a bit of juddering at junctions, it did the A66-M6-A69 journey effortlessly - no sign of slip. I am still annoyed to think any mechanic would treat a car like that! And does worn down clutch friction material induce DMF looseness/slap?What exactly is it that happens to the DMF? Is the mechanic's behaviour likely to have shortened the life of anything else other than the friction plate?

Comfortably Numb · 28th March 2019, 20:31

Just had a thought - you would think either the front wheels would have started spinning, or the back wheels would have been dragged - I couldn't see whether he also had his foot on the brakes!

markypicks · 29th March 2019, 18:36

i fitted an original rover mount last year it cost me 40 quid the rubber inside breaks up so fitted a new one and it sorted it rgds mark

markypicks · 29th March 2019, 18:38

Quote:

Originally Posted by Comfortably Numb

Thanks for the encouragement Brian. I was given a last-minute change of workplace , Brampton, Carlisle - a 70mile round trip instead of the 20 miles to Penrith and back. I decided to risk it with the Rover, instead of the slow and thirsty 4x4. Needless to say, apart from a bit of juddering at junctions, it did the A66-M6-A69 journey effortlessly - no sign of slip. I am still annoyed to think any mechanic would treat a car like that! And does worn down clutch friction material induce DMF looseness/slap?What exactly is it that happens to the DMF? Is the mechanic's behaviour likely to have shortened the life of anything else other than the friction plate?

and hes prob burnt off 6000 miles of clutch wear in doing so rgds mark

clf · 29th March 2019, 20:24

Do you not get clutch judder with a worn thrust bearing too? (Along with noise when depressing the pedal)

Sent from my SM-A600FN using Tapatalk

27th March 2019, 17:40	#1
Comfortably Numb Posted a thing or two Rover 75 Saloon Join Date: Dec 2017 Location: Penrith Posts: 1,336 Thanks: 165 Thanked 303 Times in 241 Posts	DMF? What's the point? So, as posted in Technical (with no response), the CDT, after 132kmiles, has developed clutch judder as you set off. Once on the move, or standing idling, totally vibration free, it's fine, pulls like a train, 80 over Shap, I even took it to the ton a couple of weeks back. But the judder has been getting harder to avoid. So today I phoned the ex- Rover dealer near me, and described the symptoms. DMF says he - I used to do quite a few. "Strange" thinks I, "the general opinion on the forum is that DMFs are not a problem on these, especially if the clutch hasn't been abused - which it hasn't. In my 45 years of driving, I've needed 3 new clutches in my cars , 2 of which expired while being driven by someone else (and no, I don't lend my cars so someone else can take the blame!) Anyway, I took it to my usual garage after work, and asked the mechanic "How do you tell whether your clutch judder is DMF or oil on it?". "I'll show you" says he. So he starts her up, pulls the handbrake full on, puts it into gear, and starts to let the clutch out, building up the power as it starts to bite, and over about 15 seconds, pulling harder on the handbrake as it tries to move, he finally gets the clutch to slip with the pedal apparently fully up., and strong smell of burning clutch, but not burning oil. Nor did it seem to produce the judder I experience on normal take-off. "Your clutch is worn out"says he with a grin " So why does it judder? I've driven cars with worn clutches before, and they've been smooth up to the point where if you accelerate hard, it revs like an auto!" "DMF has room to slap about if the clutch is worn ". Can someone explain how this can be. Broken spring(s)? Why, if you never let the clutch out quickly? Driving home, I didn't floor it, but I accelerated fairly briskly in all 5 gears along the dual carriageway, and while the bite is right at the top, once engaged, it doesn't slip under acceleration. Oh and it's an un-modified 115bhp motor. I think I'll just run it till it does slip in normal driving, then get rid. It will never be worth the cost of repair, despite it's 2001 Connie spec and rust-free body.

27th March 2019, 17:45	#2
bl52krz This is my second home Rover 75 cdt club + Rover 2.5 KV6 Conni SE Join Date: May 2008 Location: Birmingham Posts: 11,387 Thanks: 6,587 Thanked 2,262 Times in 1,729 Posts	Could it be the tear drop at the rear of the gearbox? __________________ Great Barr, Birmingham.

29th March 2019, 18:36	#8
markypicks Gets stuck in rover 75 saloon cdt club se re map 160 bhp Join Date: Dec 2018 Location: sheffield Posts: 558 Thanks: 227 Thanked 169 Times in 135 Posts	i fitted an original rover mount last year it cost me 40 quid the rubber inside breaks up so fitted a new one and it sorted it rgds mark Last edited by markypicks; 29th March 2019 at 18:41..

29th March 2019, 20:24	#10
clf This is my second home MG ZT CDTi Join Date: Jan 2014 Location: carrick Posts: 7,859 Thanks: 3,494 Thanked 2,657 Times in 1,973 Posts	Do you not get clutch judder with a worn thrust bearing too? (Along with noise when depressing the pedal) Sent from my SM-A600FN using Tapatalk __________________ It is not gloss primer .............. it is duct tape silver!

27th March 2019, 19:15	#4
Comfortably Numb Posted a thing or two Rover 75 Saloon Join Date: Dec 2017 Location: Penrith Posts: 1,336 Thanks: 165 Thanked 303 Times in 241 Posts	Thanks, guys. I'm taking my van in to work tomorrow, and I'll get the car up on ramps at the weekend to check the gearbox rear mount. That will be a lot cheaper than the £800 + the 2 garages estimated for clutch and dmf replacement. Fingers crossed you have correctly identified the problem.

27th March 2019, 20:58	#5
marinabrian MG ZT Join Date: Jan 2011 Location: Newcastle Upon Tyne Posts: 20,151 Thanks: 3,565 Thanked 10,837 Times in 5,718 Posts	Andrew fit the clutch yourself, it's not a bad job, to do it properly takes a little extra time as the subframe must be removed to do the job. A three part clutch kit can be found HERE for a shade over £116. Finally, I would never take the word of someone who deliberately wrecks what is left in terms of friction material by doing what he did to "demonstrate" DMF failure........what a complete moron Brian

28th March 2019, 20:24	#6
Comfortably Numb Posted a thing or two Rover 75 Saloon Join Date: Dec 2017 Location: Penrith Posts: 1,336 Thanks: 165 Thanked 303 Times in 241 Posts	Thanks for the encouragement Brian. I was given a last-minute change of workplace , Brampton, Carlisle - a 70mile round trip instead of the 20 miles to Penrith and back. I decided to risk it with the Rover, instead of the slow and thirsty 4x4. Needless to say, apart from a bit of juddering at junctions, it did the A66-M6-A69 journey effortlessly - no sign of slip. I am still annoyed to think any mechanic would treat a car like that! And does worn down clutch friction material induce DMF looseness/slap?What exactly is it that happens to the DMF? Is the mechanic's behaviour likely to have shortened the life of anything else other than the friction plate?

28th March 2019, 20:31	#7
Comfortably Numb Posted a thing or two Rover 75 Saloon Join Date: Dec 2017 Location: Penrith Posts: 1,336 Thanks: 165 Thanked 303 Times in 241 Posts	Just had a thought - you would think either the front wheels would have started spinning, or the back wheels would have been dragged - I couldn't see whether he also had his foot on the brakes!