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MG MGA - MGA Rear Springs

I am doing a frame off and have replaced the rear springs with new ones from British Springs via a US distributor. The rebound straps are 2" short of hooking up but yet they are the correct length and the rear shock arms are pointed downward at about a 60-70 degree angle.
Previous threads mention driving the car and the springs will settle in place. Any advice on "settling" the rear springs without driving the car as I am months? off from being able to do that? I now have a 7 degree driveshaft angle (way too much) and the exhaust pipe is tight against the rear axle housing.
Thanks, joe
joe Katzenberger

Simple, get 4 or 5, 5 gallon plastic containers. Fill with water and place in the boot of the car. Then connect rebound straps and remove containers.
Bob (robert)

Joe, this is a very common problem. Unfortunately I have not heard of a good solution. The springs you have bought likely have 6" camber. The proper camber is 3.6" according to the workshop manual, unloaded.
I don't believe that new springs settle, otherwise every new car on the road with leaf springs would change its height in the first few months of use and I don't believe that happens.
What to do? Do you still have your old springs? What was wrong with them?
Art

Hello Art,
Yes, I have the old springs but even after a trip to a local spring shop, they still have different cambers and appear rather mushy, weak.
I finally got the rebound straps mounted last evening and now have a 4-3/4" camber. The straps are extremely tight so maybe with the additional weight of the tub I might be o'k.
Thanks for the reply. joe
joe Katzenberger

Joe,
If your doing a frame off, i assume this means you currently have no body and no weight on the frame. If this is true, you need the proper amount of weight on teh frame just to measure. The unloaded weight that Art mentions is from all that i have ever done- a completed vehicle with an empty gas tank for starters. After this, you can measure heights and angles.

-BMC.

BMC Brian McCullough

My old springs were almost flat. The transformation in handling with the new springs was noticeable!

Before:
[IMG]http://img.photobucket.com/albums/v341/idpearl/SpringsBefore.jpg[/IMG]

or http://img.photobucket.com/albums/v341/idpearl/SpringsBefore.jpg

After:
[IMG]http://img.photobucket.com/albums/v341/idpearl/SpringsAfter.jpg[/IMG]
or
http://img.photobucket.com/albums/v341/idpearl/SpringsAfter.jpg
Ian Pearl

Art I know this subject is you pet hate but I don't understand your comment about will not settle.
When I rebuilt my car I wanted height at the rear and took my old springs to a spring maker. They re-tempered, re-arched and added an extra leave to each one. Naturally the result was that even with the body back on I could not attach the rebound straps. I therefore used the method I described above to fit them. After a few hundred miles of motoring the springs had definately settled and even with an empty boot and fuel tank the straps were easily free.
Bob (robert)

I must say that I have to agree with Art...
Springs properly made, with correct material and temper, should not settle. The typical failure mode for springs is fatigue cracking. I've done a lot of life testing of spring materials and have never witnessed settling, or stetching, unless the material or heat treat was incorrect.
Regards,
GTF
G T Foster

GTF, by the way that means something very nasty in England.
I do not think it is so much a matter of settling. The leaf spring is a ultra basic design and is therefore pretty basic performance. I believe that the spring when unused forms a position and when fitted to a car retains that profile even when weight is applied. After a period of time with weight exerting pressure to straighten the spring, FRICTION is eventually overcome and the spring takes on a different arch.
A test to see if this was true would be to measure the arch of a spring, then apply a load to either end, then after removing the load would the spring return precisely to its original shape?
Bob (robert)

I'm glad someone agrees with me! Thanks GT. The reason I belive in the "no settle" theory is that materials can be flexed up to their elasic limit any number of times and they will return to the original position, with no set. (Unless they fail by fatigue cracking)(This is the definition of "elastic limit"). So, a properly designed spring should be designed to withstand deflection up to the e.l. in normal use. So reasons for settling could be extreme punishment or poor materials or poor design. Poor materials are maybe a cause. Bob, friction can alter the resting point depending on the last direction it was flexed, but I can't see friction being biased downwards. Happy New Year everyone!
Art

Art,
I believe that springs are designed to be within elastic limits at full flex, but the constant flexing sort of anneals the metals, causing loss of tensile strength and resultant sag.
mike parker

Properly made springs should not settle.

I went through this twice with the coils on the front of my Lamborghini before giving up and having new springs made.
Bill Spohn

It is probably correct that properly made springs should not settle, but for some reason some springs seem prone to settle and others do not, even on the same car.
On the Triumph saloon cars the coil springs on the front do not often seem to settle but the coil springs on the independently sprung rear always do. Having worked on hundreds of these cars over many years I have found it rare to see cars that do not have spacer discs fitted under the rear coil springs.
I have also found the the multi-leaf square front torsion bars on the Volkswagen Kombi also are prone to settle, and have to be replaced. The rear torsion bars are adjustable to allow for settling.
The earlier comment that you do not see it on new cars is probably correct. The cars I see it on are 20-40 years old. If settling takes place early in the life of a car the design and/or manufacture are sub-standard.

Mick
Mick Anderson

Interesting, I must say that every car I have fitted new leaf springs to has after a short period of time settled down. I have not seen this happen with coil springs and so I have assumed, perhaps incorrectly, that friction has been some of the cause. Am I therefore now to assume that all the leaf springs I have ever fitted have been either re-tempered incorrectly or have been made of poor steel?
Bob (robert)

Robert,
Please accept my apologies if I have used a term that is considered offensive in England. Truthfully, I have no idea what it was.

Regards,
GTF
G T Foster

No, no Gerald you have not used an abusive term. The initials GTF when used in the UK indicate to someone that they should go away in a less than polite manner.
Bob (robert)

Robert,
Ah, so it is my name that is offensive...:)
I think I can guess what you are referring to.

Regarding the subject of leaf springs, here's an interesting site...www.suspensionspecialists.com

Also, as I understand it, suspension "settling" generally refers to the fact that springs are installed without the chassis weight applied. When the weight is applied, the springs "settle" to correct height. Also, friction between the leaves, under load, will cause a leaf spring to have slightly less "arch" then when unloaded. The rubber bushings also compress over time.
It is possible, due to an overload caused by a bump or excessive weight in the vehicle that a leaf spring can be deformed beyond its elastic limit causing a permanet set which also reduces suspension height.

Regards,
Gerald
G T Foster

To continue this thread:
I believe I do need to replace my rear springs since the drivers side is sagging and it is quite a bit softer in turns when the weight transfers to that side. These are the second set of Moss supplied springs.
Does anyone have the name of a good spring supplier who has springs to fit the MGA of good quality??
John
John

1. the archives are full of comments on rear springs.

2. your rebound straps will soon break, I guarantee it.

3. the arch of the springs, even the ones from england, is way too big. you can get all the facts in the archives for the correct arch

4. my solution was to use 1 or 2 of the long leaves from the old springs with the rest from the new set, or maybe it was the other way around. changing combinations of old and new gave me the correct ride height.

5. another method is to have a spring shop curl the ft eyes the other way

6. don't count on them settling very much.

7. check the archives for the correct ride height at the center of the wheel wells. you can alter the ride height by adding or removing the shortest leaf.
Fred H

Although not cheap, Doug Jackson has carbon fiber rear spring. See them at his site mgbmga.com .

Randy
Randy Myers

I put new Moss Darlington rear springs on my car two or three years ago. They settled after a couple of weeks driving to the point where I could attach the rebound straps without strain. These have not settled measurably since.

I also replaced the front coils. These settled too, but much less. The first time I hit a bump hard there was a huge TWANG from the front end as the spring settled properly into the pan, and that was it.

dominic clancy

This thread was discussed between 29/12/2004 and 14/01/2005

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