Screaming blower motors Log Out | Topics | Search
Moderators | Register | Edit Profile

Australian RR Forums » Miscellaneous » Threads to 2010 » Screaming blower motors « Previous Next »

Author Message
Top of pagePrevious messageNext messageBottom of page Link to this message

Bill Coburn
Moderator
Username: bill_coburn

Post Number: 1061
Registered: 4-2003
Posted on Tuesday, 30 December, 2008 - 20:12:   Edit PostDelete PostView Post/Check IP

Recently I have had this problem in a 1970 Phantom VI and '72 Corniche and a '72 Shadow. One turns on the blowers and quite unpredictably they produce a teeth jarring screech which lasts for many seconds before settling down to a quiet hum. Clearly,(love that term) it is dry bearings. The Phantom had had some extra special treatment by having the accessable bearing housing drilled so that a little machine oil can be dribbled in. But the others it seems were not generating noise with their rear bearing ie the one away from the squirrel cage fan but the other end. Incidentally the noise is not unlike the screeching of the electric servo motors on the various flaps. I finally ran out of excuses to avoid pulling these things out and stripped the one on the Shadow. Sure enough the bearing is worn but usable but the lubrication has been so poor that the steel on the motor shaft surface of the bearing has actually 'picked up' and was scored. This I corrected with a strip of emery and a good soaking of the porous bronze bearing. Put it all back together and so help me the screech was back! I was reaching for the razor blades and baring my wrists when I thought to go check the other motor! You've guessed it. I'll write this up in Topics but thought you might like a heads up in the meantime.
Top of pagePrevious messageNext messageBottom of page Link to this message

Paul Yorke
Prolific User
Username: paul_yorke

Post Number: 266
Registered: 6-2006
Posted on Wednesday, 07 January, 2009 - 00:25:   Edit PostDelete PostView Post/Check IP

I'd add that if yours do screech when you turn them on, turn them off very briefly until they silence and then back on again.

This is obviously not a fix, but will stop the Banshee faster than letting it sort itself out :-)

It's best to sort them before they seize and damage the motor windings etc.
Top of pagePrevious messageNext messageBottom of page Link to this message

Bill Coburn
Moderator
Username: bill_coburn

Post Number: 1067
Registered: 4-2003
Posted on Wednesday, 07 January, 2009 - 05:12:   Edit PostDelete PostView Post/Check IP

Paul/ I wonder whether anyone has thought about a new service schedule based on time. The latter factor seems to have far more impact on a car's survival than mileage? The list is growing and this in but one 'do it before you have a real problem'!Transmissions are being driven until they start disintegrating steering systems are grinding themselves to a paste diffs are clogging up through sheer neglect and fairly serious rubber bits are fast rotting.

I wonder whether any other Marque 'nuts' worry about these things and devise some sort of qualitative maintenance?
Top of pagePrevious messageNext messageBottom of page Link to this message

Laurie Fox
Experienced User
Username: laurie_fox

Post Number: 50
Registered: 6-2004
Posted on Wednesday, 07 January, 2009 - 06:41:   Edit PostDelete PostView Post/Check IP

Bill

It seems to me that what maintenance you do and when is dependent on how you use the car. I bought B420EY in 1959 with 97,000 miles on the clock to provide reliable transport over a long period of time. Two things have helped enormously in doing this successfully.

The first is to keep some records. In my case there is a "day book" which is the primary place for notes as to work done and condition of the parts involved. These entries are subsequently transferred to a ledger with sheets laid out like a Workshop Manual so that all work on say "petrol pumps" is in one place.

From all this a picture begins to build up as to what is the service life of the various assemblies which is an invaluable guide to not doing unnecessary work as well as planning what to do when some stripping out is needed. I have the advantage of being the only driver (apart from MOT testing) so I know how the car has been driven since the last jobs have been done.

Some jobs are mileage dependent and some are time dependent so the records say when work was done and what the mileage then was. I make some notes as to the condition of parts which are not put back and, in many cases, retain the bits for later examination which I have found to be very useful. Examination of parts which I have judged to be not good enough for reuse has led to a number of "design" changes to extend the useful working life of various assemblies.

Whether to fit new parts or to reassemble the old bits is a matter of personal judgement and, obviously, the more engineering and fitting experience you have the better. My small workshop is up to toolroom standards in respect of measuring equipment so I can usually find out why a part has become unserviceable and maybe do something about it.

The second point is to have the right spares available for use when needed. If you are going to keep the car and use it then the records will suggest what spares you are likely to need in the future looking ahead as far as you feel inclined. I reached that stage in 1966 or thereabouts and stocked up accordingly. So in many cases I have new parts to compare with stripped out parts which helps in deciding whether to refit the old parts or not. Establishing the reason for a part becoming unserviceable is an important part of the game.

I am well aware that my way of running a MK VI as a working car is not what would be practicable for many owners but I would commend the use of a "ledger" as a step in the right direction.

Things change as time goes on. I am now well into my 90's with an invalid wife to look after so there is not much motoring. But I don't have an invalid car. It is used regularly for short shopping trips every week but virtually nothing else and has done less that 400 miles in the last two years. But it is never cold started since the block heater is switched on for some hours before a shopping trip. Oil changes are done at MOT times in spite of low mileage, back axle in 2007, engine in 2008 and hopefully gearbox in 2009 (Nov.). The odometer is now at 412,000 miles - not a very high annual average mileage but it does mount up over the years.

Regards

Laurie
Top of pagePrevious messageNext messageBottom of page Link to this message

Bill Coburn
Moderator
Username: bill_coburn

Post Number: 1068
Registered: 4-2003
Posted on Wednesday, 07 January, 2009 - 08:08:   Edit PostDelete PostView Post/Check IP

My dear Laurie/ You put us all to shame. Your system would be quite beyond me. Whilst rapidly catching you up in the age stakes I can't even keep a diary and when I do write one up I forget to look at it! I think what I am aiming for is a planning memory jogger for each model so that those who can be bothered can look down the list and wonder whether the ground crystal stopper in the Waterford decanter could do with a little bit of reseating.

I now use service sheets which I have compiled from Factory Handbooks and I am starting to add items in there largely to jog my memory. It doesn't hurt to be reminded of the decanter even if you just tick it off for next time. I am of course being facetious. The problem is compounded with vehicles later than yours because of their complexity and probably accessability or the messiness of doing the job.

Even with your car things like the centre bearing for the tailshaft or chassis rivetts loosening (and they do), that mess of rods waiting in attendance on the brake servo with all their seldom oiled pins etc the list is there and they are so easily overlooked until the big surprise.

I love dogs probably more than my cars and when either get into trouble I get quite upset. The solution is not to let me have either!!!

Have a great year, you are an inspiration to us all!
Top of pagePrevious messageNext messageBottom of page Link to this message

Martin Cutler
Prolific User
Username: martin_cutler

Post Number: 105
Registered: 7-2007
Posted on Wednesday, 07 January, 2009 - 08:17:   Edit PostDelete PostView Post/Check IP

Hi Bill,

One to add to your list is the rear axle half shafts on the shadows, everybody seems to check the diff oil level, but doesn't take out the bolt to check the oil in the half shafts. I seem to find a lot of these dry.

Marty
Top of pagePrevious messageNext messageBottom of page Link to this message

Bill Coburn
Moderator
Username: bill_coburn

Post Number: 1069
Registered: 4-2003
Posted on Wednesday, 07 January, 2009 - 08:49:   Edit PostDelete PostView Post/Check IP

Yes Martin they certainly are an old chestnut. I am always intrugued how the left hand ones seem to not lose their oil as much as the other side. There is a theory that the revolving somehow puts the oil into the diff through the breather hole in the drive shft! Personally I think it has something to do with the water exiting the bath tub theory ie direction of swirl!
Top of pagePrevious messageNext messageBottom of page Link to this message

Paul Yorke
Prolific User
Username: paul_yorke

Post Number: 267
Registered: 6-2006
Posted on Wednesday, 07 January, 2009 - 09:10:   Edit PostDelete PostView Post/Check IP

Bill, aren't they already based on time? Over here in the UK most of my clients don't do 6000 miles per annum. Some only do 1000 or less. A couple have the same mileage as they did when I delivered it the year before.

If the car hasn't covered 6000 or 10000 miles, then annually seems to be the minimum for these cars. Lubrication wise I do everything even if the car hasn't moved since last year. Grease is squeezed out of weight bearing surfaces and oil goes off. To not grease brake rods etc because the car hasn't moved is exactly the opposite of what should be done because it's the non used ones that seize up! Spray Chain lube is ideal for things like that, fluid enough to penetrate when sprayed on, but sets to thick grease after a few days.

In fact, I'd prefer a car that does 2000 miles a year to one which does say 100. Very low mileage cars are (IMHO) often overrated. Ones that have been serviced at main agents are likely to have been valeted and given back to the customer without a spot of grease been added.

Personally, I find it takes longer to to keep looking through job cards to see what you did last (partial) service than to do the whole lot. This ALWAYS includes tightening Exhaust manifold bolts and engine sump bolts.

Maybe I'm a fool to myself and if I only did 1/2 the job, I'd have much more work next year :-) Unfortunately for my family but fortunately for the cars and owners, I wasn't taught that way.

I always note any advises on the job card so I can warn the customer next year, and order the parts in ready.

Plugs, points, thermostats, hydraulic components, hoses, transmission services etc., I tend to take on merit and examine each car and component to assess condition. I find out what use the car will get within the next 12 months and decide from there. IMHO Time and distance are no indication on these lifespans.

Of course with the newer cars with service indicators - we don't have to worry any more! The ECU's use complex algorithms to work out when the service is due. Cold starts, engine run time, town driving, motorway driving, miles covered, litres of fuel used, ambient air temperatures etc. are all continuously monitored to let the driver know the optimum time for servicing their vehicle.

Almost all of my clients cars service indicators come up due to time, annually anyway! :-)
Top of pagePrevious messageNext messageBottom of page Link to this message

Paul Yorke
Prolific User
Username: paul_yorke

Post Number: 268
Registered: 6-2006
Posted on Wednesday, 07 January, 2009 - 09:13:   Edit PostDelete PostView Post/Check IP

Maybe it's roundabouts?

I wonder if European cars have the right hand one fuller? :-)
Top of pagePrevious messageNext messageBottom of page Link to this message

Laurie Fox
Frequent User
Username: laurie_fox

Post Number: 51
Registered: 6-2004
Posted on Wednesday, 07 January, 2009 - 11:09:   Edit PostDelete PostView Post/Check IP

Bill

The idea of a check list is a good one since new owners will have a positive suggestion as to what to look for. How far it should go into things which are not reasonably normal wear and tear or age related is difficult to decide. It will be a fairly long list in any case and the items will need grouping into some sort of structure if it is really going to be useful.

One of the items on such a list might well be "check compression". What action should then be taken?

I think that it all depends on whether the owner is mechanically minded or not. A car is always talking to you when you drive it but whether you can understand what it is trying to say is another matter.

In one sense a check list already exists in the owners handbook. All pretty basic but probably sufficient for the first ten years of the life of a car and assuming that the owner will get professional support as necessary. Then there is the next level of more detailed information in the various workshop manuals and dealer bulletins. Some dealer bulletins provide a feed back on discovered weaknesses and their correction but none really deal with the problems facing a new owner of a car which may well be over 30 years old. This is where bulletin boards and the like come in and the extent to which the information provided is useful depends on what kind of reader is doing the reading.

We have to remember that we are trying to keep cars going which are well past their "use by" date. The condition of some things, e.g. Mk VI rear wheel bearings, cannot be checked and passed OK and have to be taken on trust. Some will fail and some will carry on OK and there is no means of knowing whether a given bearing is OK for another 3000 miles or so or not. So, for a MK VI, there would be no point in putting "check rear wheel bearings" on the check list.

In any case, the bulletin board or website reader has to be aware of the possibility that what he reads does not apply in his case and may be wrong anyway. There is a glorious example of this in the newly vamped BDCL website but I would probably be hauled over the coals if I said specifically what it is.

Nevertheless, in spite of all the caveats, bulletin boards like this one do a good job in educating people who are interested. I was enormously encouraged by Mark Anson's recent post saying that he had sorted out his MK VI brakes.

Regards

Laurie