Suspension misalignment

[johngosnell]

Yes, They do have packing fitted at the back also the front had the packing removed to get the front down. When The springs came from SNGB I checked the measurement of the rear ones as the length is given in the WM and they were correct. I could not find a measurement for the front springs but they are high.


John

[Orlando St.R]

It's good that the packing rings are there.

I fitted new SNGB rear springs to my car in 2015 and it sat too low. The free length measurement may be correct, but there is also the poundage to be considered (how stiff they are). I replaced the SNGB ones with 50-year-old ones.

[cass3958]

Part of my purchase of lots of boxes of spares there came four brand new rear shocks with springs and two brand new in their boxes front shocks. I have already changed the front springs so this week was out with the old in with the new.
Easy job as you do not need to compress anything and my nuts and bolts having only been on the car for four years came off with no problems. With all the bolts undone it is a very easy job just to switch out the old and put in the new, regrease the bolts and it was finished in four hours.
Although I thought there was nothing wrong with my suspension I immediately felt a tighter rear end. Not so bouncy over the bumps and less wollowy driving down the lanes.
Ride height at the front has not changed as this is governed by the springs which I did not touch but the back end has dropped down almost an inch which now makes the car sit parallel to the ground whereas I used to have a slight front end dip. The distance between the rear arch and the wire is now roughly the same as Nigel's and Orlando's.
Very happy.

[johngosnell]

Rob, if I understood correctly you are saying that spring length controls the height at the front but the rear shocks have a bearing on the ride height , as you know my rear sits lower than I would like even after replacing springs.




John

1B1257BW

[Orlando St.R]

Well done, Rob. You have been busy. And it sounds like quite a haul of parts you have sourced.

What make were the springs and dampers?

[cass3958]

The fronts were Monroe and came in their boxes. The rears I am not sure about without getting back under the car as they were loose, wrapped in bubble wrap and look like NOS.

Rob, if I understood correctly you are saying that spring length controls the height at the front but the rear shocks have a bearing on the ride height , as you know my rear sits lower than I would like even after replacing springs.

John, The springs both front and rear control the ride height not the shock absorbers.
Springs can be strange and you would think that a spring as it gets older would compress more and stay short but actually an old spring might lengthen when not under load and shorten under load as it loses its tensile shape and is no longer as stiff as it was. This would mean the car might stand higher until under load when it would sit lower and cause an uncomfortable ride over bumps as there would be more travel in the spring. The shock absorber part of the suspension just stops rebound so when you go over a bump the car will not bounce down the road like a rubber ball so they do not have any bearing on the ride height. You can buy fully adjustable coilovers, pretty standard on a motorbike and I had them on my Lotus Seven, where, by the use of a collar and thread, you can adjust the ride height of the car by adjusting the length of the spring under tension over the shock absorber. You could buy a longer or shorter spring to sit on your shock absorber and again this would alter the ride height. Stiffer springs will allow the car to sit higher than soft springs when under load.
Springs and suspension are a dark art and I do not profess to know enough about it to try messing with mine other than to fit standard springs and shocks that Jaguar recommended for the car.

[Orlando St.R]

The fronts were Monroe and came in their boxes. The rears I am not sure about without getting back under the car as they were loose, wrapped in bubble wrap and look like NOS.

That's interesting, then. I have a set of rear NOS to put on at some stage and they are grey.

What did you have on there before, btw? The originals?

Rob, if I understood correctly you are saying that spring length controls the height at the front but the rear shocks have a bearing on the ride height , as you know my rear sits lower than I would like even after replacing springs.

John, the dampers on our cars don't have any effect on the ride height. Only dampers with adjustable spring platforms, which came along later, allow you to change the ride height of a car.

[Glyn Ruck]

Look at this suspension mess-up that is being advertised by a local dealer.

suspension ride height wrong.JPG (67.17 KiB) Viewed 6674 times

[Orlando St.R]

Look at this suspension mess-up that is being advertised by a local dealer.

Wow! What have they done to that?

[cass3958]

Orlando,

What did you have on there before, btw? The originals?

From the service records I have with the car which are extensive, a new pair of rear shocks were put on the car in November 2001 and they have only done 6000 miles. Both were put on the same side of the car??? and I could tell this as they were white in colour. It only mentions shock absorbers so I do not know if the springs were changed at the same time.
On limited funds when I rebuilt the car I checked the shocks and they were fine so after a good clean up which involved removing the springs I replaced them on the car but put one of the newer shocks on each side. Always meant to come back to this and change them to new when I could afford it. I suspect that the other two were originals as there is nothing else in the service history to suggest they had been changed. I am also assuming that the front shocks were originals although I changed the springs two years ago for uprated stiffer springs from WatJag.

The ride has really improved. Over certain speed bumps in Torquay even slowly with no one in the back I would hit the bump stops so the springs were completely shot. No problem now with the new rears in place.

Look at this suspension mess-up that is being advertised by a local dealer.

Well there are no words really! Air ride??
Don't forget to contact them Glyn and get the cars details for the registry.