Rear spring tension

ZedsGirl · Post by **ZedsGirl** » Tue Jan 15, 2013 9:50 am

Please forgive me if the lingo is not 100% correct but my husband is challenged when it comes to computes so it is left to me :?

We have a 1964 Series 1 Fixed Head E-Type Jag 3.8. We have put new shocks on the car but the spring are so stiff that there is no flexibility. Can anyone help us with the correct testion settings?

ZedsGirl · Post by **ZedsGirl** » Tue Jan 15, 2013 9:53 am

I meant tension - sorry for spelling.

ZedsGirl · Post by **ZedsGirl** » Tue Jan 15, 2013 9:54 am

Ok, what I need is the spring rate for the front and rear springs? Does anyone know the weight of this car?

Post by **Heuer** » Tue Jan 15, 2013 12:46 pm

The car weighs 24.5 cwt but that is not really of consequence provided the rear shocks and springs are correct for the car. They are not adjustable. The front suspension is controlled by torsion bars and shocks which can be adjusted to set the height of the car. There are several threads on the subject:

http://etypeuk.com/forum/viewtopic.php? ... hlight=irs
http://etypeuk.com/forum/viewtopic.php? ... hlight=irs
http://etypeuk.com/forum/viewtopic.php? ... hlight=irs
http://etypeuk.com/forum/viewtopic.php? ... rsion+bars

ZedsGirl · Post by **ZedsGirl** » Tue Jan 15, 2013 1:31 pm

Thanks David. I seem to have found a company who may be able to help. Classic Jaguar in Texas, mailed them and will relay any useful info.

MarekH · Post by **MarekH** » Tue Jan 15, 2013 2:20 pm

The long and short answer is that if you have adjusted the front torsion bars as much as you can to get the ride heght correct both front and rear but it is still low at the rear, then you need a new set of rear springs.

kind regards
Marek

vee12eman · Post by **vee12eman** » Tue Jan 15, 2013 8:48 pm

Hi,

What Marek says is true of the standard set up up the cars. However, I had a similar issue, my car was low at the rear and the availablity of accurate rated springs in Australia was questionable. I was left with the choice of replacing the springs which should correct the ride height, or replacing the shock absorbers with ride height adjustable versions, which, with a little work, definitely would correct the height.

The latter course of action was the one I chose and now the car rides at the correct ride height and is adjustable if I choose to change things. I will however stress that shock absorbers do not have any influence on ride height or, as is oftem mistakenly thought, the "level" of the car, unless they are specifically designed shock absorbers which allow you to change the overall spring length using adjustable spring platforms.

My car is a Series 3, but the principle is the same for all types and the adjustable height shock absorbers are available for all E-types.

Regards,

Simon

PeterCrespin · Post by **PeterCrespin** » Wed Jan 16, 2013 1:16 am

Adjustable spring seat dampers do not change the 'overall spring length' when fitted to the car. They alter the ride height until/unless the damper is fully extended, which does not happen when the mass of the car is supported on the springs.

They alter fitted length only, while the damper is off the car. Once on the car the same load is carried with the spring at the same compressed length regardless of spring seat position. It's just that the car's resting height rises or falls with the spring seat.

Pete

abowie · Post by **abowie** » Wed Jan 16, 2013 5:20 am

Is it possible that you have been supplied the wrong springs? the springs for the series 1 and 2 cars are different to those fitted to the series 3.

ZedsGirl · Post by **ZedsGirl** » Wed Jan 16, 2013 5:31 am

Thanks for the advice. My problem is that the car sits too high. I am in South Africa and the previous owner put new shocks/springs (not specifically for a series 1) onto the car. It thus has NO give. Have managed to get settings from XK Eng, but may have to order new and specific for car shocks from them as this looks like it's going to be best solution. What do you think?

vee12eman · Post by **vee12eman** » Wed Jan 16, 2013 6:56 am

Hi Zedsgirl,

I am not completely sure what you mean by NO give. If you mean the car will not compress when you push down on the wings abve the wheels, then I would have to say that the springs you have are too strong for the car, maybe, as has been suggested, they are from a Series 3 car. The way to tell is to take measurements. For the Series 3 car, the measurements are taken from the floor to the plate below the differential and should be 200.8 mm +/- 6.4 mm (7.9" +/- 0.25"). These measurements may be different for a Series 1, although they are probably close. They are taken with a full fuel tank, correct tyre pressures and both engine oil and coolant topped up. You probably need the figures fro the Series 1 to be sure, hopefully someone on here will have the figures and can post them for you - I strongly recommend getting a copy of the Workshop Manual.

If the car is too high then something is wrong - most likely the springs. I'm afraid I don't know what the spring rates are, possibly these are the figures you have from XK Eng, but unless you can measure them (probably requiring some special equipment or clever measuring of height change when adding weight to the car - very tricky given the design of the suspension), they probably mean nothing unless actually having springs manufactured to fit. It is just possible you have the wrong shock absorbers, compressing the springs far too much, but this is highly unlikely.

Peter is correct that adjustable shock height absorbers do not change "overall spring length" (unless GROSSLY over adjusted), sorry for the confusion, I wrote the post when in a bit of a rush and I did mean that the spring length was different (shorter) in the uninstalled state. Given your description, I think the best answer is a set of spring/shock absorbers. SNG Barratt in UK sell these ready assembled - meaning you don't have to separate or fit the springs from the shock absorbers, a job seen as too dangerous by many and the cause of much debate here recently. With the weak pound and high rate of VAT, this may be your best and cheapest option. I recently ordered my shock absorbers from them and the removal of the VAT meant that after I had them shipped here, the total cost including delivery was less than if I had picked them up in person in UK. They took three days to arrive by UPS, so I was very happy.

Hope this helps,

Regards,

Post by **Heuer** » Wed Jan 16, 2013 8:03 am

Get a set of shocks with springs fitted from SNG (you don't want to even think about installing the springs on the shocks yourself without specialist equipment). ?65 each http://www.sngbarratt.com/catalogue/par ... k=y&next=y and while you are at it buy two front shocks from the same place at about ?30 each.

ZedsGirl · Post by **ZedsGirl** » Wed Jan 16, 2013 1:50 pm

Simon and David- you are amazing - thank you. I have been in touch with SNG UK and have ordered the new front and rear sets as you proposed. I phoned them and they were very helpful. I appreciate your guidance and assistance.

Kath

Post by **Heuer** » Wed Jan 16, 2013 11:01 pm

Please let us know how you get on - glad we could help.

vee12eman · Post by **vee12eman** » Wed Jan 16, 2013 11:52 pm

Hi again,

Happy to help, stay with the forum in future!

Regards,

Simon

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