New springs longer than old ones

[ROGER B]

I am changing the rear springs on my '70 Traveller as the bump stops and back end of spring hit the chassis on even a minor (sorry!) bump. Reckon they have gone soft. I got a new pair from ESM with the correct number and they seem longer than the old ones. See photos. Any comments please?

[svenedin]

No photos seen as yet. Traveller springs, 7 leaf? “Length” depends on the curve?

[ROGER B]

Thanks for your reply. I don't know why the photos didn't appear - I'm happier with spanners than computers! - but I'll have another go now.
The camber ('curve') on both old and new springs looks similar. Both have 7 leaves and the leaf width and eye diameters are the same. I can't see how I can fit the new springs; admittedly, I haven't tried yet but as they are longer in repose they won't fit between the mounting pins - will they??

[kevin s]

Difficult to tell from the photo, If you lay one on top of the other how far out are they?

[Grumpy21]

I had exactly this when I fitted new springs to my traveller last year. They will fit but the angle of the rear shackles will be too acute and they will hit the chassis. After a little research I found a solution which involved grinding and cutting away the flange on the chassis rail and re-welding it closer to the box section. No more clunking. Was easier to do than explain, 20 mins per side.

[ROGER B]

Thanks for your response Grumpy21. That seems a bit extreme for something that is described by ESM as a top quality spring especially for the Traveller. I will have a word with them when they reopen on Monday. If they use them in their own workshop, they must know they don't fit.

[ROGER B]

Remeasuring them again today I find that the springs are actually very similar lengths. I must have been having a senior moment yesterday (again) and reckon the old spring has gone soft so flattens out under load more than the new one will. I would be surprised if ESM have got this wrong. However, Grumpy found that he had to alter the chassis rail, so I will speak with ESM before fitting them. Thanks all for advice, much appreciated.

[kevin s]

They do sell slightly longer shackles to fix the spring hitting the chassis, ours did it on original springs.

[Grumpy21]

these are mine as fitted about 18months ago, you can see the spring almost in contact with the chassis.

[philthehill]

Kevin s
Do you have a link for the longer shackle plates as I am unable to find them.
Phil

[alanworland]

A few years since I replaced my springs but mine showed contact with the rear flange and I also relieved it to clear the spring end.
They all seem too long as I would suggest the shackle ought to be more vertical when unloaded?

Alan

[svenedin]

My springs are tired (30+ years since last replaced) and I started another thread asking for advice on the job. It was suggested I get the springs from a specialist manufacturer and I have ordered from Jones Springs of Walsall. They are much more expensive than the ESM springs. I think the shackle plate sits vertically with the old springs. I will have a look and take a picture. My car is a convertible though and uses 5 leaf springs.

Stephen

[svenedin]

I just took a quick photo of an old spring that I know was last changed over 30 years ago. I couldn't get under the car because I am dressed to go to work. Anyway, the shackle plate does not sit vertical but it is not sitting far off vertical. This is an old tired spring that is sitting rather flat and if it still had its proper curve I suspect the shackle plate would be vertical.

IMG_9111.jpeg (2.2 MiB) Viewed 2879 times

[ROGER B]

I rang ESM today and, despite the camber being the same on old and new springs and the eye to eye measurement being the same, they reckon that that the old spring has probably gone soft so flattens out under load more than the new one will. At rest, the old one has been almost touching the chassis rail at the back and the bump stop gap 30mm so it regularly contacts the chassis. ESM said it was not uncommon to have to remove a little material from the chassis rail in the area behind the rear shackle on some cars, particularly those that have had new front hangers which have not been welded in precisely the correct place. The measurement between the centre of each shackle pin fore and aft should be 110.5cm (which mine are). ESM have told me to go ahead and fit the new springs and I will be very disappointed if the shackle is not closer to vertical, as leaning back like that can not be correct. I will report back!

As an aside, I am wondering if Jones Springs have the correct dimensions for MM springs should ESM ones be slightly too long?

[Grumpy21]

ESM said it was not uncommon to have to remove a little material from the chassis rail in the area behind the rear shackle on some cars, particularly those that have had new front hangers which have not been welded in precisely the correct place. The measurement between the centre of each shackle pin fore and aft should be 110.5cm (which mine are).

which is exactly what I did (see earlier post)

[kevin s]

Kevin s
Do you have a link for the longer shackle plates as I am unable to find them.
Phil

ESM don't seem to do them any more, they had them around 4 years ago when I did ours, about 1/2" longer than std ones (so roughly 1/4 inch in ride height). For another car I made a set by cutting up a piece of box section with the same wall thickness.

New springs of the same length won't fix the issue on a worn spring completely, in the static unladen condition it will be better but as soon as you hit a bump or load the car they will flatten out and the spring will hit the flange again. I also wouldn't recommend a shorter spring or moving the body attachment, you risk inverting the shackle after full rebound which is a very dangerous condition.

New poly bushes seem to help, the rubber ones avalable now seem too soft, 3 or 4mm at each shackle bush plus perhaps the same rearward movement at front is enough to make a difference.

[philthehill]

Kevin s
Thank you for the reply.
I have standard shackle plates with Minor Mania plastic bushes in the chassis rail and had standard O/E rubber bushes in the spring eye. The rear 7 leaf springs have been reset to give a 2" lower ride but with the same spring rate. The springs are flatter but do not hit the chassis leg at the rear. The chassis rail in the area of the rear spring shackle pin is original/standard and has not been repaired.
Relieving or reprofiling the flange is not unusual to give the required clearance.

[kevin s]

Phil ,

Yours is a 2 door saloon is 't it?

If so how does the ride height on a 7 leaf spring flattened by 2" compare with the standard ride height? We are loking at fitting something similar.

[philthehill]

Yep a two door saloon.
The ride height is lower than 2" as compounded by having 13" wheels and low profile tyres.
I have taken at least 1-5" off the rear bump stops.
The shackles do not foul the chassis rail even with the flat spring.

[ROGER B]

Many thanks to all who responded with rear spring advice. Happy to report that new ESM springs fitted without difficulty, except for having to make the front pins fit the hole in the plate which I did on the bench before starting the job. Now ride height correct and the springs and bump stops are no longer hitting the chassis.