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Geoff Wootton
Grand Master
Username: dounraey

Post Number: 504
Registered: 5-2012
Posted on Friday, 17 October, 2014 - 12:48 pm:   Edit PostDelete PostView Post/Check IP

This new thread follows on from one that had started on the Silver Spirit forum and drifted onto Shadows (http://au.rrforums.net/forum/messages/17001/16475.html?1413491808)

I thought I'd put up a pic of my car with it's new rear springs. This may be of interest to anyone contemplating changing their springs and trying to decide whether to go for the 10 or 11 spring variety. The ones I fitted to my car are the 11 coil variety i.e. an extra coil as used also by R.A.Chapman in Australia. The car is slightly high at the rear, however I am expecting it to settle down a little after the next few hundred miles. The fuel tank was only a quarter full when this photo was taken. A full tank will lower it a further 1/2"

car

Geoff
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Jan Forrest
Grand Master
Username: got_one

Post Number: 683
Registered: 1-2008
Posted on Friday, 17 October, 2014 - 07:10 pm:   Edit PostDelete PostView Post/Check IP

It's been pointed out in the past that carrying some decent weight in the boot for a few weeks or months can settle the springs enough to reduce the extra length of the 11 coils of the longer springs. A couple of full size bags of cement (with or without the corpse of a drug dealer with its feet in them) should be adequate.
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richard george yeaman
Prolific User
Username: richyrich

Post Number: 225
Registered: 4-2012
Posted on Saturday, 18 October, 2014 - 07:46 am:   Edit PostDelete PostView Post/Check IP

Hi Geoff I think if the overall height had been 20 inches instead of 21 and 5 eights it would have been spot on apart from the height what is the handling like do you think the car is too stiff or is it alright.

Richard.
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Bob uk
Unregistered guest
Posted From: 94.197.122.92
Posted on Saturday, 18 October, 2014 - 04:47 am:   Edit PostDelete PostView Post/Check IP

The sill trim alines with the centre of the front wheel but is about an inch too high at the rear.

In the interest of science how many litres of water does it take to drop the rear 1".

Still it looks better than down at the rear.

Incidentally the Grayston rubbers are not for under the springs but for between the coils. The hard rubber rings I mentioned are different.

If the springs don't settle then maybe cut 1/4 of coil off. I would give them 12 months before any adjustments.

(Message approved by david_gore)
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Geoff Wootton
Grand Master
Username: dounraey

Post Number: 506
Registered: 5-2012
Posted on Sunday, 19 October, 2014 - 02:38 am:   Edit PostDelete PostView Post/Check IP

Hi Jan, Richard and Bob

I have just picked up on your comments.

Jan - I'm hoping not to have to weigh the boot down, although it will be a measure of last resort, if required.

Richard: I have not done any extensive road testing yet as I have decided to investigate a clicking starter motor problem first. The car always eventually starts, most times first attempt, but I know if I persist in using it I am eventually going to get stranded. The starter motor goes back on this weekend. If I have not cured the fault, then I will replace it with a new one. As soon as I have put some miles on the car I will report back on the ride and handling.

Bob - I knew about the rule of thumb, that the sill trim should line up with the centre of the wheel hub, but this was the case on my car when the rear was low. Below is a "before" picture, taken on a slope, which emphasised the "saggy bottom". In this picture you can see the sill trim aligns perfectly with the centre of the hubcap even though the car is down at the rear. The trim is affixed to the car correctly. I'll check out some library pictures of other cars to see if the sill trim alignment holds true on all cars.

car-before

Geoff
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Bob uk
Unregistered guest
Posted From: 94.197.122.80
Posted on Sunday, 19 October, 2014 - 06:14 am:   Edit PostDelete PostView Post/Check IP

Geof the car in the last photo looks about right to me maybe the slope is making my eyes not see it.

In the solenoid on the starter is a switch which powers up the motor. It is operated by the solenoid armature which also moves the pinion forward. Check it.

(Message approved by david_gore)
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Geoff Wootton
Grand Master
Username: dounraey

Post Number: 507
Registered: 5-2012
Posted on Sunday, 19 October, 2014 - 12:03 pm:   Edit PostDelete PostView Post/Check IP

Bob

I guess it's a matter of personal taste, but I much prefer the look in the first photo. Before I changed the springs, my car definitely did not pass the test whereby you should be able to rest your fingers on the top of the tyre such that the wheelarch touches the back of your hand. The wheelarch was at least an inch below the level of the top of the tyre.

Thanks for the advice on the starter. I've stripped it down, checked the brushes, given it a good clean out, checked the insulation on the wires running to the brushes and bench tested the reassembled starter motor. The pinion operates nicely. I do have a further question, but will put it on a more appropriate thread.

Geoff
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richard george yeaman
Prolific User
Username: richyrich

Post Number: 229
Registered: 4-2012
Posted on Friday, 24 October, 2014 - 04:13 am:   Edit PostDelete PostView Post/Check IP

Hi All.

I like many of you have been using Rubber spring assisters, I have decided to replace my rear springs, I replaced a pair recently for a friend of mine and was not happy with the result as mentioned elsewhere The replacement springs were shorter and the car still didn't sit right, anyway I have found a spring maker locally who is prepared to make two sets for me (another friend needs a set also)I have several old springs to use as a sample when he asked me how many coils I needed I said either ten or eleven he said eleven would give a softer ride than ten, so as the original ones had ten now I know why.

Richard.
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Bob uk
Unregistered guest
Posted From: 94.197.122.90
Posted on Friday, 24 October, 2014 - 05:27 am:   Edit PostDelete PostView Post/Check IP

A coil spring is a torsion bar wound in a coil.

10 coils means a shorter torsion bar therefore stiffer than 11 coils and a longer torsion bar.

The other dimension that is considered is the diameter of the wire and hence torsion bar. 17 mm appears to be the diameter used. 19mm would make the torsion bar fatter and thus stiffer.

A 10 coil spring of 17 mm wire 550 mm long will be about 10% stiffer than a 11 coil spring of 17mm wire that is 550mm long.

Which is why cutting road coil springs down lowers the car and stiffens the spring.

10% stiffer is noticeable.

The wire dia is obviously fundamental to the spring rate. Surface corrosion makes the dia smaller and therefore the spring rate lower which is what has happened to my springs.

(Message approved by david_gore)
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Geoff Wootton
Grand Master
Username: dounraey

Post Number: 519
Registered: 5-2012
Posted on Saturday, 25 October, 2014 - 11:39 am:   Edit PostDelete PostView Post/Check IP

Hi Folks,

I've finally got the car back on the road and have been testing the new rear springs. I'm really pleased with the result. Whilst walking back to the car, across a car park, it looked "right". Any fears I first had about the rear being slightly too high have gone.

Handling is the same as before. There is no discernible difference. I use the word "handling" very loosely here. After all, this is a 1974 SY1. To put it kindly, it still maintains the same boulevard ride as before (of which I so enjoy).

In answer to the question I posed, 10 or 11 coils, there is not a lot in it. In an earlier thread, Richard gave the length of the 10 coil springs as 20 5/8". The 11 coil springs are 21 5/8". How much that extra inch translates into additional ride height once the springs have been fitted (and therefore compressed) I would not know, but my guess would be 1/2" max. All I can say is I am very happy with the 11 coil springs I have fitted.

Geoff
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Bob uk
Unregistered guest
Posted From: 94.197.122.82
Posted on Sunday, 26 October, 2014 - 05:24 am:   Edit PostDelete PostView Post/Check IP

The spec that seems to be right is 21 5/8" and eleven coils of 17mm wire. This should be enough data for a spring shop. I shall ask my local spring shop now I have a spec.

(Message approved by david_gore)
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richard george yeaman
Prolific User
Username: richyrich

Post Number: 288
Registered: 4-2012
Posted on Friday, 29 May, 2015 - 08:57 am:   Edit PostDelete PostView Post/Check IP

Finally got my new springs fitted last Sunday end result very similar stance to Geoff Woottons car pictured top of the page, I used 21 5/8" long with ten coils 18mm wire, I made what turned out to be a bit of a b...s, After fitting the first spring and before I fitted the second spring I noticed the Isolator had 8 or 9 shims fitted so I went on ahead and fitted it with the shims I will give the car awhile to settle in and if need be I can take them out. by the way Geoff how is your springs getting on maybe a wee update.

Cheers.

Richard.
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Geoff Wootton
Grand Master
Username: dounraey

Post Number: 722
Registered: 5-2012
Posted on Friday, 29 May, 2015 - 10:27 am:   Edit PostDelete PostView Post/Check IP

Hi Richard

I am very pleased with the new ride height, but I think I've introduced a problem. I get vibration from 35 to 50 mph. I suspect the drive shafts had, over many years, worn in to the low ride height, so with the new springs fitted I am getting the vibration. I had a short and abortive attempt to switch them, but I couldn't remove the inner joint from the diff housing. When I get time I will have another more determined attempt that may involve some very large hammers. Seriously though, I think I will take David and Brian's advice and heat the side of the diff casing in the hope of freeing it. The interesting thing is that Benoit had no trouble with his. I should be so lucky.

Regards

Geoff
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Brian Vogel
Grand Master
Username: guyslp

Post Number: 1330
Registered: 6-2009
Posted on Friday, 29 May, 2015 - 10:49 am:   Edit PostDelete PostView Post/Check IP

Geoff,

If you are lucky:

1. You will get the Detroit joints freed from the differential housing.

2. You will find that the Detroit joints have never been swapped, and that you get many decades of use from new wear surfaces after swapping them yourself.

How I wish that we were within "garage sharing" distance of one another. I've wanted a Shadow companion almost since day one. Of course, most of us "are alone" when it comes down to these cars. There are just too few of them and if you don't live in a major metropolitan area the one you have may be the only one within a great distance.

What's really strange is that there are a number of Rolls-Royce motorcars within a very short distance of me ranging from a P-III through to a Silver Spur. But each is the single example of its type. We even have a Radford SC-II (or maybe SC-I) in the area that shows up at a local British car show each fall. I was able to tell the new owner more about the car than he had heard since he bought it not all that long ago.

Brian
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shane alward
Yet to post message
Username: the_gambler

Post Number: 1
Registered: 5-2015
Posted on Friday, 29 May, 2015 - 06:34 pm:   Edit PostDelete PostView Post/Check IP

that's a fine looking vehicle. would be great to see some more of the members photos.... shane
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richard george yeaman
Prolific User
Username: richyrich

Post Number: 289
Registered: 4-2012
Posted on Friday, 29 May, 2015 - 06:36 pm:   Edit PostDelete PostView Post/Check IP

Yes that would be great to have someone close by that has a similar car that could when needed give some assistance to you when I was doing my springs last Sunday I had the help of a friend who has a shadow 11 and a spirit but he just dosent have much mechanical knowledge but he does have a willingness to learn.

Richard.
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richard george yeaman
Prolific User
Username: richyrich

Post Number: 291
Registered: 4-2012
Posted on Sunday, 31 May, 2015 - 06:22 am:   Edit PostDelete PostView Post/Check IP

I was doing a wedding today with a friend two white Shadows lovely, Three burley bridesmaids in the back of the car and the mother of the bride in the front that should help the new springs settle in.

Richard.

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