Just done a lot of fettling over the last year, been out to my local garage to get the tracking done and the rear springs are hitting the chassis rail on both sides.
With weight on car.jpg (1.34 MiB) Viewed 1384 times
With no weight on car.jpg (1.71 MiB) Viewed 1384 times
As the photos show it has new springs Poly bushes spring shackles bump stops in fact every bit has been renewed, from EMS (I think). I have checked the measurements the best I can from the photo (F G E) below, without being to precise the measurements are within 1-2 mm of correct.
Dim.jpg (134.43 KiB) Viewed 1384 times
Left hand.jpg (1.42 MiB) Viewed 1384 times
Don't know why the last photo is upside down!
The question is what else can I try before I make some slightly longer spring hangers.
I had the same trouble 3 months after fitting new springs from my usual supplier. I then ordered new springs from Jones springs; they make them to order. Also, I now have the correct gap between the bump stops and chassis. I did try 25mm longer spring hangers but felt that it became unstable when cornering.
Have a look at your springs, do they look the correct shape just aft of the front hanger or do the leaves have gaps between them?
I think you need to cut away part of the flange of the chassis rail above the end of the spring where you have contact. This was done originally at the factory and you need to replicate this before you do anything else
paul 300358 wrote: ↑Sat Oct 29, 2022 3:30 pm
I had the same trouble 3 months after fitting new springs from my usual supplier. I then ordered new springs from Jones springs; they make them to order. Also, I now have the correct gap between the bump stops and chassis. I did try 25mm longer spring hangers but felt that it became unstable when cornering.
Have a look at your springs, do they look the correct shape just aft of the front hanger or do the leaves have gaps between them?
The new look just the same as the old though thay are a couple of mill longer and they have no gaps
Old - New Spring length 2.jpg (1.31 MiB) Viewed 1351 times
ManyMinors wrote: ↑Sat Oct 29, 2022 5:01 pm
I think you need to cut away part of the flange of the chassis rail above the end of the spring where you have contact. This was done originally at the factory and you need to replicate this before you do anything else
I understand what you say but the old springs didn't hit the chassis rail at all. the new spring hangers are identicle to the old ones.
Is the arc of the old and new springs the same before fitting. Place a straight edge across the hanging points and measure the arc height at the centre point.
Fit the old spring and measure the arc height. Then fit the new spring and take the same measurement. What do you get?
Ours was the same, I made some 1/2" longer side plates for the shackles,.
If the bushes are OK and the body is correct the only issue can be the springs are too long, curvature may effect the static condition but under compression they will all go flat at some point.
Peted7202 wrote: ↑Sat Oct 29, 2022 8:01 pm
Is the arc of the old and new springs the same before fitting. Place a straight edge across the hanging points and measure the arc height at the centre point.
Fit the old spring and measure the arc height. Then fit the new spring and take the same measurement. What do you get?
Just in from doing as you suggested and there is only a couple of mill difference old to new both off the car and with the weight on the springs
With that in mind I’m going to try making some new spring hangers, I’ll probably ad about 20mm to them and see how the car rides.
ManyMinors wrote: ↑Sat Oct 29, 2022 5:01 pm
I think you need to cut away part of the flange of the chassis rail above the end of the spring where you have contact. This was done originally at the factory and you need to replicate this before you do anything else
I’m reluctant to grind the chassis leg down as it has just been stripped to bare metal etch primed, under coat, stone chipped and top coated, if I can get away with it I will. I cant understand how the old springs didn’t hit the chassis rail!
In my considered opinion the spring rate is not correct.
It is how the spring has been tempered determines the spring rate.
The new spring can look identical to the original but how it works under deflection is the important aspect.
To determine the new spring rate relative to the original spring - turn the spring upside-down, measure and note the distance between the ground and the top of the spring. Load the top of the spring and measure the deflection downwards.
Repeat several times, each time making notes of the load weight and deflection.
Do the same as above on the old spring, each time making notes of the load weight and deflection.
Compare the notes and see what differences there are.
From the photo above there appears to be a small difference in overall length. That small difference in overall length can have an effect on how quickly the spring eye hits the chassis leg flange especially if the spring rate is lower than the original spring rate.
If the old and new spring rates are not comparable, I would be speaking with the new spring supplier.
Phil
I agree Phil. If the new and original springs when fitted have the same arc height then the difference in length of the new springs will push out the hangers and hence reduce the spring end clearance. Increasing hanger height is not the solution. This is treating the effect not the cause and may have unitendered consequences.
The photo above makes the actual fitting on the end of the spring look a little 'fatter' than the original.
What's the view from the side?
Are the new hanging points a little larger diameter than the original?
Peted7202 wrote: ↑Sun Oct 30, 2022 8:48 pm
I agree Phil. If the new and original springs when fitted have the same arc height then the difference in length of the new springs will push out the hangers and hence reduce the spring end clearance. Increasing hanger height is not the solution. This is treating the effect not the cause and may have unitendered consequences.
As I said above, I purchased springs from ESM in May, the same thing happened. After about 3 months, the car sat 25mm lower and the bump stops banged the chassis when going over any uneven road. I suspect that they had never been heat treated. New springs were purchased from Jones Springs, the car now sits at the right hight, has yet to hit the bump stops and is very smooth when going over bumps.
The ESM springs are stored behind the shed awaiting transport to the local recycle centre.
Many new springs are supplied with pretty poor straps securing the leaves together, maybe an indication to buying, would be to check the springs have the proper metal securing bracket. The top picture is correct, the bottom one, placed on to show how some are supplied !
839D8D53-6D93-43A8-9088-086615C3FDF6.jpeg (126.6 KiB) Viewed 1208 times
s.
Attachments
FA823C66-50F4-4F29-AAC0-DFAF99407184.jpeg (97.25 KiB) Viewed 1208 times
geoberni wrote: ↑Mon Oct 31, 2022 9:19 am
The photo above makes the actual fitting on the end of the spring look a little 'fatter' than the original.
What's the view from the side?
Are the new hanging points a little larger diameter than the original? Spring.JPG
The internal size is correct maybe it was just the angle I took th photo at
I’ve been on to ESM where I bought the springs from, I actually bought the full kit SUS660A they say that its never happened before so I said I would send them an email with some of the photos I have took and measurements of the old and new springs. I will update when I hear from them.
The problem comes with return postage, they are heavy. I just decided to put it down to experience. The Jones Spring replacements cost 3 times as much as the ESM ones, but they are made to the original specification.
FosterS wrote: ↑Mon Oct 31, 2022 12:20 pm
The internal size is correct maybe it was just the angle I took th photo at
I guessed the internal diameter would be correct in order for the bushes to fit, but like you say, it might be the perspective from the camera angle.
On you latest photo, the older one looks the larger of the two.
Is the metal of the spring the same thickness?
I'd be getting a micrometer, or at least a steel rule, across each of them.
