Clutch failing - any help / advice
cosmicicecreamman - 28/10/17 at 09:41 PM
Good evening all, would appreciate some help / advice / assistance on an issue I'm having with my car eating clutches, which I think may be due
to an alignment issue - maybe caused by making my own bell housing.
I recently fitted a 2.0ltr Duratec to my Sylva Riot with an Elite racing transmissions sequential gearbox, Playskool paddle shift with DTA S100 ECU -
as it's a mid engine the gearbox is a FWD.
First time out on track (without the paddles being set up properly due to time constraints) the clutch failed on downshift after 4 track miles which I
assumed was down to the downblip not actuating the throttle sufficiently. After splitting the engine I found the centre had been ripped out of the
clutch.
Fitted a new clutch, got the paddles set up properly on the rolling road, and hit the track with everything working as it should. after about about
25miles, after a big spin and me stupidly not dumping the clutch (DOH!!!), the clutch started slipping. Split the engine and gearbox and found the
clutch to have heat spotted the flywheel and also ripped the centre out of the clutch.
Now... As the Duratec and the sequential gearbox had never been mated together, FWD gearbox as it's in a mid engine car, there wasn't an off
the shelf bell housing so made my own. I machined a bar to fit into the spigot on the Duratec clutch with a centre mark on the other end, and with the
bell housing made up to the engine scribed the PCD of the gearbox onto the gearbox face of the bellhousing, which I thought would be sufficient to
align the two shafts.
The flywheel is a lightened ST150 flywheel, with a MK1 For Mondeo clutch, as it's 220mm with a 1" 23T input shaft for the gearbox. I've
currently got the flywheel and clutch down at CG motorsport clutches who will be making an uprated clutch / pressure plate - the clamping force of the
original clutch is insufficient.
After doing some research it seems that the centre being ripped out of a clutch can be due to misalignment.
Has anyone had or seen a similar problem before? Is this an alignment issue or purely a clutch which is no capable of withstanding the forces put
through it? Any advice on what the alignment tolerances should be between an engine and gearbox? Any ideas on how to check the alignment?
Many thanks for anyone's time.
[Edited on 28/10/17 by cosmicicecreamman]
[Edited on 28/10/17 by cosmicicecreamman]
mark chandler - 28/10/17 at 10:24 PM
did you have to force the gearbox onto the engine? The first motion shaft will have a little end float to allow for minor discrepancies.
it could just be very harsh gear changing that's ripped the centre out, you could try a non sprung driven plate or paddle clutch.
cosmicicecreamman - 28/10/17 at 10:44 PM
Engine and gearbox bell housing align very well and were fitted by one person picking it up, sliding the input shaft into the clutch, aligning the
bolt holes and with minimal force pushing the bell housing onto the dowels on the engine block.
Yeah my thoughts with the first clutch were that it was just a harsh gear change - it was locking the rear wheels on the downshift, although it was
wet. The second clutch lasted well until the spin but that was with the paddle shift set up properly and working well both on flat upshift and
clutchless downshift with the throttle blipping well, although I didn't press the clutch during the spin.
I'll be upgrading the clutch with a CG motorsport one, but still not sure if i'll go with non sprung and / or paddle. My only concern with a
non sprung centre is that if there is something wrong with the drivetrain then I'm moving the problem from a relatively cheap and easy component
to replace, to potentially damaging my gearbox which is not so easy or cheap to replace.
cliftyhanger - 29/10/17 at 05:28 AM
That sort of damage is just like what happens on old Triumphs if they have a bent engine backplate. Not by much either.
Double check the 2 faces of the bellhousing are parallel. It only needs to be a tiny bit out, and will still assemble up OK. That is the easy part to
check, though I expect you have more than once.
Double check the flywheel is running true.
I am head scratching about how to check the alignment of engine/box. I guess you need some accurate drawings, and make up a plate that is a dummy of
the back of the engine but with an accurate hole for the input shaft. I guess it could be made using a std gearbox/bellhousing, but would rely on zero
play in the input shaft.
02GF74 - 29/10/17 at 08:04 AM
How can you tell if clutch is out of alignment?
I guess the difficulty is that you need to see the clutch but can't as it is hidden inside the bell housing?
Would glueing a small felt tip marker so it just touches the edge of the clutch, turning the engine over and seeing if the clutch is marked by an
almost continuous line do i?
It assumes that the clutch is perfectly round.
Or drill small hole in bell housing for a thin stiff rod to attach to a dial gauge.
[Edited on 29/10/17 by 02GF74]
fazerruss - 29/10/17 at 08:16 AM
Any pics of the bell housing, what is it made from and how did you make it? What machinery do have available?
Do you have a DTI and a big enough surface plate to check the two mating surfaces are parallel?
Have the surfaces of the bell housing been skimmed after the bell housing was fabricated or was it machined from one piece of material?
mark chandler - 29/10/17 at 08:45 AM
When I checked alignment on a home made adaptor I laid a large piece of card over the front of the gearbox and tapped around the locating holes, dowls
and input shaft with a ball pain hammer, then transferred this to the engine.
Schrodinger - 29/10/17 at 11:24 AM
Are you sure that the first motion shaft is engaging in the end of the crankshaft?
cosmicicecreamman - 29/10/17 at 08:49 PM
quote:
Originally posted by cliftyhanger
Double check the 2 faces of the bellhousing are parallel. It only needs to be a tiny bit out, and will still assemble up OK. That is the easy part to
check, though I expect you have more than once.
Double check the flywheel is running true.
I am head scratching about how to check the alignment of engine/box. I guess you need some accurate drawings, and make up a plate that is a dummy of
the back of the engine but with an accurate hole for the input shaft. I guess it could be made using a std gearbox/bellhousing, but would rely on zero
play in the input shaft.
I haven't checked the two faces are parallel, will give that a try.
The first clutch failed on the standard flywheel, and then the flywheel was changed for the second clutch. Doubt that the flywheel won't be true
but will check.
My thoughts for checking the alignment to the box are to machine a shaft to fit into the spigot of the crank, which is long enough to stick through
the bell housing. Place a DTi on this shaft and from that check for any offset from the bolt holes, or machine another plate to mate up to the bolt
holes and check for offset from the plate.
quote:
Originally posted by 02GF74
How can you tell if clutch is out of alignment?
[Edited on 29/10/17 by 02GF74]
Clutch was aligned with a machined aluminium bar that located into the spigot of the crank, so pretty confident this is good, although I was pretty
confident it was all good until it started eating clutches!!!
quote:
Originally posted by fazerruss
Any pics of the bell housing, what is it made from and how did you make it? What machinery do have available?
Do you have a DTI and a big enough surface plate to check the two mating surfaces are parallel?
Have the surfaces of the bell housing been skimmed after the bell housing was fabricated or was it machined from one piece of material?
Bellhousing was a Duratec – Type 9 aluminium housing that I mounted to a 1” thick steel plate (to stop it from warping), cut the type 9 mounting face
off, welded on an aluminium plate, and got machined to the required overall length. I don’t personnaly have access to machinery but plenty of local
machine shops around.
I have a DTI and as mentioned by cliftyhanger I will check that the faces are parallel
quote:
Originally posted by Schrodinger
Are you sure that the first motion shaft is engaging in the end of the crankshaft?
The input shaft does not engage into the end of the crankshaft. I took the design of the standard Fiesta ST150 input shaft which does not have a
reduced step to engage into the crankshaft. This is something I had not thought about before… I will have a look and see if I have any photos of the
input shaft I can post up (I'm not with the car so can't take photos).
Many thanks for all the responses so far.
[Edited on 29/10/17 by cosmicicecreamman]
motivforz - 29/10/17 at 10:59 PM
The centre plate failing can be a symptom of a difficult installation putting too much force on it. I prematurely failed a clutch through the same
failure mode (sheared the clutch plate centre section), most likely because I let the input shaft take some of the weight of the gearbox when
installing it back into the car, before I could get bellhousing bolts in place. In this position the clutch plate is supporting the gearbox alone
(with me struggling to Jack/hold it). I suspect this yields some of the clutch plate and causes a premature failure. Its not likely to overheat it
though, so perhaps not your issue...
davidimurray - 30/10/17 at 12:23 PM
What is the fit like of the end of the main shaft into the end of the crank? When I fitted my type 9 to my Duratec I had to fit a support bearing in
the end of the crank. Doesn't look like there is anything in yours.
cosmicicecreamman - 30/10/17 at 07:23 PM
quote:
Originally posted by motivforz
The centre plate failing can be a symptom of a difficult installation putting too much force on it
The installation is relatively easy, I can lift the gearbox on my own and locate the shaft into the clutch and bellhousing onto the dowels without any
real issue or excessive force. The overheating is caused by the clutch slipping due to insufficient clamping force so really a separate issue.
quote:
Originally posted by davidimurray
What is the fit like of the end of the main shaft into the end of the crank? When I fitted my type 9 to my Duratec I had to fit a support bearing in
the end of the crank. Doesn't look like there is anything in yours.
The input shaft does not locate into the crank. I took the design of the gearbox input shaft from the Fiesta ST150 gearbox that was previously mated
to the engine which did not have a spigot to locate into the crank.
Many thanks for all the responses.
I think the best course of action is to get the bellhousing checked for angular misalignment, as mentioned by cliftyhanger and fazerruss, which should
be relatively easy.
The difficult thing to check will be parallel misalignment – which will have to be done with the bellhousing mated up to the engine and some sort of
mock gearbox input shaft machined to mimic the gearbox in place…
I will update when I have results – again, many thanks.
mark chandler - 30/10/17 at 07:47 PM
Whatever the problems you are having that looks like a great job you have done there.
I would be locating the spigot to the crank, the flywheel in my car carries the spigot bearing, if nothing else a nicely greased phosphor bronze bush
machined up cannot hurt.
daviep - 30/10/17 at 08:19 PM
To check whether your bellhousing is square to the input shaft, which is what will determine parallelism of the shafts, you need to mount a DTI on the
input shaft and rotate the shaft so that the clock sweeps around the bellhousing.
Might require a bit of technique / interpretation due to the slop in the input shaft
Cheers
Davie
daviep - 30/10/17 at 08:29 PM
quote:
Originally posted by cosmicicecreamman
The input shaft does not locate into the crank. I took the design of the gearbox input shaft from the Fiesta ST150 gearbox that was previously mated
to the engine which did not have a spigot to locate into the crank.
Many thanks for all the responses.
Presumably the gearbox is designed not to have the input shaft supported?
Cheers
Davie
birdii - 31/10/17 at 09:47 AM
Does the bell housing align to the gearbox using that nice machined round bore that i can see in the photo?
If it does and this is a centre to the gearbox then split the bell housing from the box, bolt it on to the engine and set up a clock from crank or
flywheel and run it inside your location bore.
You can then move the clock and position with a 90degree finger and check the swash to determine if all faces are parallel.
There would be a small error from crank bearing clearance but alot less than you would get from the gearbox shaft.
Another trick i have used for checking shaft alignment is to set up a clock and carefully assemble then check the readings using a small hole to gain
access with a borescope isnpection cam. This can be tricky and involves some trial and error and a good understanding of DTI's.
Dan
birdii - 31/10/17 at 09:49 AM
Looking at the photos again you have quite a lot of access through the clutch arm hole so you could set up a DTI from here and read with a mirror or
cam.
cosmicicecreamman - 31/10/17 at 06:53 PM
quote:
Originally posted by daviep
Presumably the gearbox is designed not to have the input shaft supported?
From my understanding the input shaft support is only required with a long input shaft such as a type 9. The gearbox manufacturer made the shaft and
at no point mentioned that it needed to be supported. If I was getting the input shaft manufactured again I would get and input shaft support machined
but too late now.
I think what is listed below is the solution for checking parallelism between shafts... I will have to check for angular misalignment first though, as
if I do not correct for angular misalignment first, then the parallel misalignment results will not be valid.
quote:
Originally posted by birdii
Does the bell housing align to the gearbox using that nice machined round bore that i can see in the photo?
That I don't know. The gearbox was aligned to the crank rather than to the machined round bore - but it is a machined round bore and the perfect
surface to take a reference off of.
quote:
Originally posted by birdii
If it does and this is a centre to the gearbox then split the bell housing from the box, bolt it on to the engine and set up a clock from crank or
flywheel and run it inside your location bore.
You can then move the clock and position with a 90degree finger and check the swash to determine if all faces are parallel.
There would be a small error from crank bearing clearance but alot less than you would get from the gearbox shaft.
If I do as Dan has said:
- Split the bell housing from the gearbox, put a DTI onto the fly wheel / crank, mark TDC onto the bell housing, . and check to see if there is any
offset from the machined round bore on the bell housing in 90 degree intervals
quote:
Originally posted by daviep
To check whether your bellhousing is square to the input shaft, which is what will determine parallelism of the shafts, you need to mount a DTI on the
input shaft and rotate the shaft so that the clock sweeps around the bellhousing.
Might require a bit of technique / interpretation due to the slop in the input shaft
quote:
Originally posted by birdii
You can then move the clock and position with a 90degree finger and check the swash to determine if all faces are parallel.
There would be a small error from crank bearing clearance but alot less than you would get from the gearbox shaft.
Then, combining what Dan and Davie have said:
- Bolt the bell housing onto the gearbox, and do the same method but with the DTI onto the gearbox shaft, check to see if there is any offset from the
machined round bore on the bell housing in 90 degree intervals, and compare the two results to see if there is any parallel misalignment.
As both Dan and Davie say, there will be more play on the gearbox shaft, but I don't think there is any other way to check.
Spoke with CG Motorsport Clutches this afternoon. They have the clutch and flywheel and are currently looking at the failure mechanism of the centre
so hopefully that will shed more light on what is happening.
As I've said before, many thanks for all the responses.
Steve
[Edited on 31/10/17 by cosmicicecreamman]
cosmicicecreamman - 31/10/17 at 09:25 PM
If anyone's interested, here are a few pics with the gearbox installed.
Riot - 3
Riot - 2
Riot - 1
Cheers
Steve
steve m - 31/10/17 at 10:06 PM
As an un educated guess, could you have to much throw on the clutch, and thus over extending the plates/springs ?
plus you have a novice sticker on the back, 
steve
[Edited on 31/10/17 by steve m]
cosmicicecreamman - 31/10/17 at 10:34 PM
quote:
Originally posted by steve m
As an un educated guess, could you have to much throw on the clutch, and thus over extending the plates/springs ?
plus you have a novice sticker on the back,
steve
[Edited on 31/10/17 by steve m]
Don't think that's an issue, the clutch slipping is down to insufficient clamping force. The clutch is only disengaged when the starting
stopping as it has a sequential box with clutchless changes.
Yes, novice on the sticker from 2015 when I done some circuit racing but didn't really enjoy the championship. Hopefully going to do some rounds
of the CSCC next year, probably Croft and Oulton, as they're the closest to me. Currently checking eligibility of my car.
Oddified - 2/11/17 at 10:13 PM
quote:
Originally posted by cosmicicecreamman
My thoughts for checking the alignment to the box are to machine a shaft to fit into the spigot of the crank, which is long enough to stick through
the bell housing. Place a DTi on this shaft and from that check for any offset from the bolt holes, or machine another plate to mate up to the bolt
holes and check for offset from the plate.
[Edited on 29/10/17 by cosmicicecreamman]
That's how i've done a few bell housing conversions (adaptor plates or welding two half bell housings together). I've never had any
clutch / alignment issues. Personally i'd have the input shaft going into a spigot bearing, any flex under load/bearings on the input shaft and
it's bending the clutch plate even if it seems perfectly aligned on assembly and checking.
Ian
cosmicicecreamman - 4/11/17 at 02:15 AM
quote:
Originally posted by Oddified
Personally i'd have the input shaft going into a spigot bearing, any flex under load/bearings on the input shaft and it's bending the clutch
plate even if it seems perfectly aligned on assembly and checking.
Ian
As it's a front wheel drive gearbox it doesn't have a long input shaft. The IB5+ box that was originally mated to the engine didn't
have a spigot so that's why I didn't get one machined.
Agree, if I were to get it machined again I would get a spigot, but as the original gearbox didn't have it I didn't think it was
necessary.
Hmmm... I'm starting to think that this may be the cause... Think it's a call to the gearbox manufacturer... Surely they wouldn't make
an input shaft for a gearbox that would cause it to fail...
[Edited on 4/11/17 by cosmicicecreamman]
Schrodinger - 4/11/17 at 08:34 AM
Just another thought, is the clutch release bearing pushing through the centre of the clutch when the pedal is at full travel(depressed)?
cosmicicecreamman - 5/11/17 at 11:19 AM
quote:
Originally posted by Schrodinger
Just another thought, is the clutch release bearing pushing through the centre of the clutch when the pedal is at full travel(depressed)?
No, clutch release bearing fits well with the clutch cover and doesn't push through centre. It fails during clutch less up and down shifts too so
no interaction between the cover and the plate.
cosmicicecreamman - 5/11/17 at 11:27 AM
So...
I've emailed the gearbox manufacturer and asked them if there is a spigot required for the input shaft for support. I'm really hoping it
isn't required as at no point was I told there was a spigot required for support.
CG Motorsport are making me a clutch plate with solid centre, and uprated pressure plate to give a higher clamping force.
Bellhousing is away to a machine shop to get the faces checked for angular misalignment which will be machined if any is found.
Once the angular misalignment has been checked / recified I will use a DTI to check for shaft parallelism. I'm really hoping this isn't the
issue as this means modifying the gearbox mounting holes on the bellhousing.
Cheers for all the help and suggestions.
Steve
