|
|
|
| Vehicle |
Various with Autobox |
| Year |
Various |
| Mileage |
55,000 |
| Repair Cost |
circa £650 |
| Repair Part(s) |
Torque Convertor repair kit |
On three occasions over the past six months the
same subject has cropped up on the List and we pooled information from many
owners to pin the subject down, and perhaps to answer the question.
The question was about a vibration which appeared to be from the rear in
automatic cars, when changing up. The first owner compared it with the noise
made by the car passing over 'rumble strips' or the illusion lines painted on a
major road approaching a roundabout.
Andy started this off on the 31st January 2002: Talking about his wife's Scorpio
2.0 16V auto-
...when the Gearbox changes up to top gear either with O/D on or
off, there is a serious vibration from the rear somewhat like running over a
rumble strip. After a few seconds this goes away and the car drives smoothly
after this.
Jon replied at once with, as it turned out, a very perceptive observation.
Mine also makes the rumble when changing up. A bit more
investigation leads me to believe it's the torque converter clutch shuddering as
it engages -- if I put my foot slowly down in fourth, the engine revs jump by a
couple of hundred revs (upwards) when the engine starts to labour, which I
presume is the torque converter clutch letting go (if I put my foot down further
the box kicks down with a rev change of 500+). If I then move off the gas I get
the rumble again as the torque converter clutch re-engages. Also the rumble
seems to occur more obviously when the torque converter gets locked up under
significant torque. I haven't been able to observe the rumble in third at all --
if I could I'd expect that the rumble would not be present in third when in
sports mode, but would be in economy mode. Is this representative of your
experience of the shuddering when you've got the O/D switched off?
Owners replied to other issues that Jon had raised about straight-line stability
and aggressive gearchanges, while I posted a TSB that I had seen.
If the build code of your Scorpio is TR or TA then there are
issues which have been notified to main dealers.
1) The rear seat belt anchor bolts must have at least 4 mm clearance in the
holes stamped in the rear axle crossmember, and
2) There should be a minimum of 10mm clearance between the fuel filter and the
differential and a minimum of 13mm between the fuel
filter and the rear stabiliser bar.
If you jack the rear wheels up and use axle stands, look up underneath the rear
axle crossmembers - there is a hole drilled through them to allow clearance for
the seat belt anchorage points. Check the clearance there. If there is
insufficient clearance it could be the cause of the rear axle noise you can hear
- these holes need to be enlarged, either by a main dealer or a local garage.
Look up at the fuel filter, on the passenger side next to the diff. Check for
10mm clearance there. Then unhook the stabiliser bar and swing it upwards and
check there is 13mm clearance. If not you can bend the filter mounting plate
until there is.
These items could be the noise you can hear when changing up. (TSB52/1996)
Another cause of vibration could be the prop shaft damper, which
was revised in 1996.
This was not helpful, as it turned out. Meanwhile, Andy replied to Jon,
My wife's car doesn't actually make a rumbling sound just has a
vibration that feels like running over the rumble strip at the side of the road.
The Box is actually not leaking - in fact nothing on the car leaks which is a
first for a car that I have had involvement with, even my V reg Galaxy leaks
occasionally. The vibration occurs only going up to top gear with OD on or off,
so I think it is a speed related thing. As has been suggested by some other
emails, I am going to check the Propshaft damper. The car was an ex company
Director mobile (as opposed to a repmobile) so I would have thought it should
have gone in for any recalls, but then the guy might have been lazy.
After a short pause, the same symptom was posted by another owner on the 6th
February:
I am having trouble with the auto box on my 24v Ultima estate
1995,the problem is with the lock up, when in overdrive the car feels as if you
are driving over a cattle grid!! Switch the o/d off car is smooth- I have had
car in transmission shop at present, been there a week to replace the torque
converter. The question is has anyone experienced this and if so was it the
converter? I have had the ecu checked for errors: only 3 appeared - right/left
bank lean and solenoid c error. A recon box was fitted by previous owner approx
20k miles ago but not sure about the converter. Are boxes a week point on these
cars ?
So the phrase was coined - Cattle Grid.
Suddenly I realised that the noise which Jon and Andy was talking about was the
same that I had noticed on my 24V Estate, but in my case occurring only on
acceleration under load up hill: -
I have the identical model to yours. Occasionally when thrashing
I can hear an odd noise from the rear of the car as you describe, but only if I
apply too much welly before the box changes down. If I ease off and then reapply
the pedal pressure the noise does not re-occur. Recently I had a software
update, and I've since noticed that the odd cattle-grid noise is much rarer. I
find now that if I know I'm going to need acceleration, I switch out the o/d and
raise the revs in anticipation, and then floor it and the noise doesn't happen.
I've also noticed that in Sport mode the noise does not occur either. Over the
past 3 years the noise has not got worse and the software update has improved
it.
If I floor the throttle from stationary the box will change smoothly through all
the gears right up to 140mph without the noise, so I think its the lock-up
timing rather than a serious problem, at least with mine. If you get the noise
every time you try to accelerate hard then your problem is definitely worse.
BTW I had a tecchie listen to the noise once. He agreed it was there and checked
the car for two TSBs which mention rear axle noises but the car didn't have
those faults, so it was never solved. He reckoned it was axle-tramp due to the
sheer torque coming through to the rear wheels. He believes that the 2 litre and
2.3 litre cars don't get it. I would be very interested if any of those owners
have experienced the same thing, because it will blow his theory out!
I drive mine with mechanical sympathy and avoid it but if you get the noise all
the time then it will have to be sorted.
Andy recapped what he had written earlier:
This sounds like exactly the problem I am having with my Wife's
Ultima Saloon 2.0 16V. However mine happens when it changes into top with or
without OD on. Feels like running over a rumble strip however the vibrations
feels like it comes from the back of the car. I am going to book mine in to
check the rear axle, shocks, propshaft and bushes. It doesn't feel like it is
coming from the Auto Box itself. I have problems with the Autobox but I am going
to get that re-programmed as there is the known harshness problem which can be
cured by having the box programmed.
Mike came up with another possibility - programming in the EEC-V
- and gave a warning about assuming a mechanical problem instead of a software
issue. He had had bitter experience of this, as he relates;
I have had this problem in the past on various occasions on my
24v 1995 saloon. I don't think it is the rear axle though I think it is in the
box. and I don't think it is the box at fault I think its the PCM not making its
mind up about what it is telling the box to do.
I have just had the engine wiring loom replaced on my car, corroded due to a
water leak between the heads from the heater take off manifold. my box has
displayed all kinds of unbelievable problems and in the end there is nothing
wrong with it. The car has been road tested with the new loom in and it runs
perfectly with no quirks and no errors in the FDS.
Also one ford dealer told me that the box was knackered and would need
replacing. Stan at Meteor Ford (Brum) tells me it is ok. Apparently one measure
of the box condition is how long it takes to put on the power when first put
into gear. Allowance is up to 4 secs. mine is just around 2 secs. Over 4 secs
and the 'seals' are knackered (which ones I don't know). Stan says mine is fine
plenty of life left in it yet the car has done 105k, all but 3 done by me and I
have these problems on and off for 3 years.
You can see the story of my box under fault finding - water leaks...
I will ask Stan more about these gearbox issues when I speak to him next and let
you know anything interesting.
Meanwhile, on the 7th February Andy replied to my point about axle tramp, and we
could rule that out:
My wife's car that does this is a 1995 2.0L 16V Ultima Saloon so
I don't think torque causing axle tramp is the problem. Also the car doesn't do
this changing through the gears until it hits top gear. I wonder if having the
box reprogrammed to fix the harsh gear changes (mentioned in a TSB) will make
any difference.
I replied,
Right, that's that excuse out the window, then, thanks m8. It
appears its a common thing. Because on mine it happens only on high torque on
acceleration, I also wondered if it could be the box not changing down quick
enough, and causing the rear axle/prop shaft to resonate. If I'm in sports mode
it doesn't happen, which would fit. Have you tried yours in Sports mode to see
if it happens?
I just ease off whenever I get the noise so it doesn't bother me too much.
Another owner, Jim, now reported the same symptom:
My 1996 2L / 16V saloon also has the resonation ... normally
about 55 - 65mph, always in top, and worse when fully laden. Backing off a
little or harder acceleration seems to cure it. I'll
try in Sports mode tomorrow.
So the noise was much more widespread than I had ever expected, and indeed it
seemed so common that I was surprised that Ford has never recognised the issue
in a TSB. So I posted a mail asking for reports from later vehicles, trying to
pin down the years for the effected vehicles.
This is fascinating, because I have heard this noise for the past
three years and just thought it was my car, or if not then it was just the 24V
Estate. Now it seems that the noise effects all Scorpios. If the car had
remained in production Ford would probably have researched it and changed the
design of the transmission to cure it, but since production ended in 1998 they
didn't bother.
The TSB mentions a clearance of the rear seat anchor bolts in the rear
suspension arms and the location of the fuel filter too close to the diff or the
rear nearside anti-roll linkage. Perhaps my techie was wrong and it is this
issue in which case I will re-work mine and report back the result with photos
so that everyone else can do the same.
Just to check that it is the axle noise mentioned in the TSBs, can anyone with a
1997 or 98 model reply and say if they have heard the resonation (cattle grid)
noise on acceleration in top? Positive as well as negative replies would be
useful, thanks. The rear axle was revised in March 1996 so vehicles after that
date should not have the noise.
Three owners replied with a good cross-section of Scorpios:
Never heard it in my October 1995 24V
Smooth as a whistle.....our one :-)
Not a dicky......chaps quiet as the proverbial grave.....etc...etc (fingers
crossed)!
I've got a '98 24v Estate (nearly 90,000 miles), and have never had any problems
with noise from the axle.
Meanwhile Jon persisted with his own theory about the Torque Converter:
If you find a steep hill (I can do it on most gradients, but the
2.9 will
need some load I imagine) and push put your foot slowly down, does the torque
converter release noticeably before kickdown? If you then release the throttle
so the torque converter locks back up (under high torque as you're on a hill) do
you get the noise again?
On my 2l these exact same symptoms seem to be associated with torque converter
lock up. (I've been moaning away in the background about this one for months
;-). Someone suggested a leaky torque converter? If I take out my starter I
certainly have an accumulation of transmission fluid in the converter
housing.
My symptom was different from Jon's Scorpio.
No the only time I ever hear the noise is when I'm accelerating
hard between 55 and 65mph - and I'm talking hard acceleration for overtakes -
and only for a few seconds and then it dies away. If I ease off the accelerator
and then re-apply it the noise has gone.
I am never aware that the torque converter clutch has operated unless I look at
the rev counter which suddenly rises or falls - there is no other indication of
the lock-up operating at all and the noise does not re-occur.
Meanwhile Mike had had some work done at a Ford dealer, and asked him what the
noise might be:-
I asked him about the juddering and when I said it was like going
over a cattle grid and that several of us had suffered from it he immediately
sparked up and said he knew what it was. He took me to a draw full of auto box
bits etc and said the following.
The ATF pump connections to the torque converter - there is a seal and depending
on the working of the seal the torque converter lockup clutch is on or off.
The seal is like a piston ring, metal square section and about 1.5 inch diameter
and 2 mm by 2mm cross section. This sits in a groove in the body of the torque
converter somewhere I think but I am not sure. This ring/ seal is always pushed
in one direction and that side of the ring gets worn, so the ring rather than
having a square section ends up with a notch worn in the one side. This the
allows leakage of oil and the ring can move back and forward in its groove. this
causes the problem, the worn ring results in the converter lock up clutch at the
front of the box to go on and off rapidly.
Ford describe this as the auto box cattle grid problem. Ford say fit a new
converter. Stan says fitting a new metal seal will cure it and he has done it
several times.
This may be the answer or it may be something else!!
Well, this certainly fitted the symptom. I replied,
Thanks for that, Mike. Did he happen to say about how much the
replacement cost? (gulp)
I've had the noise on mine since 46K miles and it's not got noticeably worse to
91K.
Mike had asked that question!
Well he said it was about 10 hours at £50 an hour to get the box
out
and then some work on it. The kits are only 20 quid - he was talking about
checking seals and various things once the box is out. So it could be 600 (plus
the dreaded vat) unless you are vat registered and can claim it back as business
expense of course.
As if to confirm this, Colin Lewis posted his result of work in an Auto
Specialist on the 8th February:
Just got my 24v estate back from a transmission specialist ,new
torque converter, seal and lock up seal fitted, the very harsh vibration (cattle
grid effect) ,seems to have all but disappeared ,but after spending £635 I
suppose it should have. The car is now much smoother and the lock up almost
unnoticeable. I can highly recommend QAS transmissions in Bristol - very helpful
people who seem to know what they are talking about, but the same cannot be said
of OLYMPIC WARRANTIES ,who underwrite the warranty that came with car, waste of
time and money, basically because converter did not break!! no claim would be
considered.
This was by no means an unusual complaint about the 'Warranty' cover sold with
used cars.
So from a lot of individual questions in isolation we seemed to
have reached a conclusion. The 'cattle-grid' effect was not the matter mentioned
in the TSB that I thought it was. The symptom appears to be caused by the wear
in a seal in the pump to the Torque Converter.
Then there was nothing on the List for over a month, until Nick posted a mail on
the 14th March, reporting some issues with his ABS and air con, but also the
following:
MOST Worrying is the throbbing vibration that rocks the whole car
when accelerating hard through 60-80 mph as the auto box changes up. I first
though that rumble strips had appeared at all motorway junctions! But when
accelerating gently none or only slight vibration is felt. The vibrations are
very like those felt going over rumble strips or the hard shoulder white lines
and only last around 1 second but come in sets of two or three.
Any views?
Mike answered with the result of his investigation into the symptom:
If there are no other strange symptoms it could be a worn seal in
the torque converter. There is a seal in a cylinder type pipe that feeds the
torque converter clutch and it is like a piston ring in a piston, except it is a
ring in a cylinder wall not in a piston, and this gets hammered back and forth
and wears thin and then it can vibrate in its groove. My Ford mechanic who is
pretty knowledgeable said this was the cattle grid vibration and is well known
to Ford. But perhaps only well known to few Ford mechanics.
Now Colin was able to suggest another cause, and this was pause for thought.
I have a 24v estate ,and recently had similar problems with
vibration eventually getting worse until on one long run I also lost o/d. I took
the car to a company called QAS in Bristol who road tested the car and diagnosed
a torque converter problem. Apparently this cattle grid effect is quite common,
but they also suggested that the airmass meter may also be having an effect on
the problem, and suggested that the converter and seals, be replaced and to run
the car for a while. After this was done, the vibration had gone, but the o/d
was still slipping on occasions, so the car went back to QAS, a new airmass
meter fitted and o/d fault cured. This also cured a problem I had at idle with
CC on the revs used to hunt up and down - when cc was turned off it would idle
ok. Apparently I have heard since that when Ford were first aware of problem
they used to change converter and airmass meter as a matter of course. Hope this
helps
This was intriguing - since the airmass meter (or MAF - mass airflow
meter) is easily and relatively cheap to replace, perhaps this could be done
first? Nick had taken this on board and visited the same specialists, and on the
15th March posted this:
I have been to QAS in Bristol and they suggested it was the airmass meter which
needed replacing and this should fix it. But, they also suggested that damage
will have been done internally by this fault and I should have the converter and
seals done at the same time - £580 gulp!
Should I just get the airmass meter changed? or go the whole hog and have the
torque converter and seals changed? or is there a simpler (cheaper!) fix?.
Steve advised a test substitution:
I'd get them to change the airmass meter (10 minute job) and then take it for a
drive - if the same symptoms were there I'd get them to put the old one back and
book it in for a new convertor/seals
On the 19th March 2002 Allan posted the question again. Had we got to the bottom
of it?
Did anyone get to the bottom of the 'rumble strip' sensation some
of us are getting when the auto box changes up? I read about possible torque
converters or prop shaft but I would like to know if anyone has actually cured
the fault. If so, did you do the work yourself? It does feel as if the vibration
goes from front to back and I wondered how the torque converter could give this
effect. I am not keen to let a garage do the work and I have not been stumped
yet with previous mechanical repairs on my last Mk3 Scorpio.
Nick replied to him, hoping that it could be the MAF sensor for economic
reasons:
From the conversations I have had, I am a little confused as to
how the airmass meter could cause this effect. I hope I can be convinced because
it does look very easy to replace DIY, although at £109 it's still not pocket
money. Otherwise it's £400 for seals and torque converter replacement which I am
assured is a specialist job - poo!
On 20th March I tried to sum up with the following post:
Yes, this thread was fascinating because I had experienced this
noise for years and learned to change my driving style slightly to avoid it. I
always assumed it was connected to the design of the rear axle, which had been
slightly redesigned, and it was a revelation to know many others had noticed the
same thing. I think it was Steve Congrave [actually Mike Walsh] who posted that
his autobox specialist immediately identified the noise and pointed out the
culprit - which meant a gearbox out job. I think someone else said the same
thing. One voice did say that it might be the MAF - and this is a possibility.
If you look at the page EECV you will see that a fault with the MAF
can cause faulty gearshift scheduling and late or early disengagement of the
torque converter clutch. I can say, with mine, having experienced the noise from
the first at 46,000 miles, that it hasn't got noticeably worse at 94,000 miles
and 4 years later. I would have thought that if the MAF were faulty it should
have failed altogether. Another thing I might add that since I had a software
update the noise occurs much less often. I personally don't plan to start
tinkering with the autobox unless something else happens (I'd better touch wood
here)
Things were quiet again for another month or so - and then on the 26th May
another posting reminds us how common this symptom is In reply to a posting from
Oliver asks:
Problems again with my 24v Estate auto box back in Jan this year
I had the dreaded cattle grid effect and then complete loss of overdrive, so
into transmission shop new torque converter
What is the dreaded cattle grid effect? I wonder if it's the same thing that I
get when for example I overtake someone on the motorway and when it changes up
into top gear it sometimes feels as though I'm going over a corrugated surface!.
Jon posted : -
Yup, that's precisely what the 'dreaded cattle grid effect' is.
Welcome to the 'cattle grid effect club' :) The problem is due to a worn seal
causing the torque converter lock-up clutch to oscillate in and out several
times when it engages.
The reassuring news is that it may not be as 'dreaded' as we make out. Certainly
list members have reported having this problem in excess of three years and
suffering no other ill effects. I find that by timing my acceleration to avoid
the transmission being under high load when the torque converter locks up (ie.
changes to third and fourth and after long medium acceleration when the torque
converter lock-up has dropped out) I can avoid the problem to a large extent;
which can't be a bad thing.
Mike posted his experience which mirrored mine - heard for some years but not
worsening:
I have had this cattle grid thing over three years but only
occasionally. It may be a combination of a worn part and then the
electrics not sure what gear to select and the timing thereof based on a varying
hydraulic pressure coming from the worn part. mine always just last a second or
so and clears by just taking the foot off for a moment and then letting it
settle down and carry on. Whole process just a second or two and only once every
month or two, so not too bad.
On 11th June 2002 the subject was raised again in connection with the use of
cruise control on the 2 Litre Scorpio. Steve B posted:
I'm sorry if I'm going over old ground - but here goes!
I took my 1995 2.0 16v Ultima auto on its first long run down to
Devon last weekend. Taking the opportunity to use the cruise control, I
found that on even the slightest inclines the box shifted down a gear and then
back up again, seemingly undecided about which gear to be in.
I just put this down to the 2.0 engine being a bit under-powered,
although I hadn't really noticed anything when motoring without cruise engaged.
After this, I got a couple of jerky gear changes and in a couple of
instances I felt what is very accurately described as the "cattlegrid
effect."
On the way home I didn't bother with cruise in case it happened
again and had a good trip back.
Around town since it has been perfectly normal but I have checked
the fluid level and suspect that it is a little low (just above the first
notch).
As there is no reference in my handbook to checking this, I'm not
sure what level it should be or what fluid to use to top up.
Does this ring any bells with you boffins out there.
After some advice about checking the autobox fluid levels, Allan went on:
Regarding the cruise control and erratic gear changes, mine is
exactly the same and it's annoying and disappointing. I usually disengage the
cruise just before a hill to avoid the constant up and down shifting and
screaming revs that ensue.
I feel there is something amiss with the setup of the 2L cars, although I have
checked for software updates and none were available. I would love to have this
problem solved by one of the lists electrical boffins.
My previous 2L 8v Mk3 Scorpio auto suffered no such problems and once in cruise
mode it never changed up on hills. Generally, I find the new 2L unrefined and it
revs too highly at low cruising speeds (3000 at 70mph). Boy do I wish I had gone
for the 2.3 or 24v.
Welcome to the cattle grid club! Mine also does this on a regular basis but only
usually uphill with cruise on. I am increasingly concerned with the number of
reports of list members with this problem on low mileage cars (mine s done
72,000 and the problem has been there for the last 20,000). Perhaps there is
some value in approaching Ford about their failing torque converters (this is
cited as the culprit) as it may have warranted a TSB or recall.
Again, with reference to my Mk3 with the ALD4 box, it did 170,000 sterling miles
and is still going strong with the new owner without ANY gearbox attention
needed.
Conclusion
Now, how can we sum up?
On 24V cars the symptom appears to effect only acceleration, can be avoided by
easing off slightly on the accelerator and then resuming power. The effect has
been noticed for some years without apparently getting worse.
On 2.0L cars the gearbox seems to 'hunt' more when using cruise control, and the
cattle grid noise is apparent while the cruise control is breasting a hill and
on both up and down changes.
Some cars, of all production years, report no symptom at all, but may be
explained by gearboxes or torque converters replaced in service.
Owners have reported that the symptom is well
recognised by Ford technicians as the Cattle Grid effect, and it has been
reported that a seal ring in the Auto Fluid Pump to the torque converter wears
unevenly and causes fluctuations in the TC or TCC. Several owners have reported
that a renewal of the torque converter has cured the symptom. A repair of this
nature has cost owners in the region of £600 including labour, excluding VAT.
Other owners report that the MAF sensor may aggravate the problem and changing
this can have a beneficial effect. This would cost in the region of £120 and can
be replaced at home quite easily.
And where is this seal? On the right is the diagram of the A4LDE gearbox pump
housing. It is the open end of the autobox in which the Torque Converter sits
when the unit is bolted to the engine.
Ringed is the seal, exactly as Mike described it. His mechanic mentions that the
seal kit only costs £20, but the labour in changing it is about 10 hours!
Thanks to all contributors for permission to use their posts.
Diagram ©Ford Europe
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