About 20 years ago I replaced the original springs because the rear end was listing to one side. I was never happy with the replacements they were a thicker wire and shorter. Over the years they started to soften and car was sitting too low at rear. A few years ago replaced shocks with Gaz adjustable that also had adjustable perches. This made it possible to set the height correctly. Within a couple of years car was listing to one side again. Currently, have one side perches set higher to compensate but don’t think that this a good idea as a fix. Just got the Moss flyer and see coil springs and went looking at other suppliers and found SNG has a spring just for the Gaz shocks. It is about 2 1/2" shorter with fewer coils, equates to a harder ride? It seems all springs I find are rated “uprated”. Looking for something rated as close to original as possible. Front torsion bars are set correctly so the is no blame there.
Glenn
70 E
Howzaboot a custom spring maker? I’m sure the spring rate of the originals can be found out, and most spring makers would find them a doddle to make.
I wish I had kept my original springs to compare. When I lived in So. Indiana there was a supplier to NASCAR that would make the locals springs shocks and radiators.for the SCCA crowd.
Classic Jaguar states their springs are manufactured by a NASCAR supplier, my guess the Indiana supplier. CJs springs are “uprated” @$250. for set.
Glenn
Bet a spring maker can make’em for half that.
I’ve had springs “retensioned” in the past by a spring maker (Henderson’s in Sydney). They had sagged as you describe. Was a heating and cooling process. All I had to advise was the original unladen spring length. All worked well in my Triumph (now long gone). You would have to source some old original springs to go this way. Paul.
I’m still running the original springs in my '68 ots, on adjustable shocks. The left spring perches are 1/2" higher than the right. Been this way for a long time, but I usually set the left side of the car 1/4" higher than the right to compensate for single driver effect. Doesn’t seem to affect anything.
I suspect the GAZ shocks take a standard 2.5" ID spring. Go to Summit Racing and look up “coilover spring”, you should find a wide selection of brands, including Eibach, QA1, Aldan, and Summit. Pick ths length you like. About 250 lbs strength is right.
Thanks Terry, makes me feel better that I am not alone.
Michael, Summit does have a huge selection of springs to choose from.
Terrys Jag lists specs for their springs, lengths and lbs. starting @275 for mild race,
so maybe 250 lbs. is right on.
Glenn
Another point to mention, the original springs had more coils than the replacements. Do not remember the coil count but replacements have anywhere from nine to eleven coils. My thinking the more coils there are the better?
Glenn
The more coils the softer the spring, wire diameter and coil radius being equal.
Why not just swap your current springs from one side to the other? Or put one short one and one long one per side?
Andrew
I thought about just swapping springs around, but would like to have it set up correctly.
This is the one car I own that I know where the limits are and can drive up to them.
My other cars are far more capable than I am, until I get the guts to push them that far.
The new springs are cheap insurance.
Glenn
The length and strength of the spring will determine the number of coils. The strength is going to be around 250lbs for a decent compromise between ride and good handling. The height is a function of shock travel and diameter. This may be different for the Gaz shock than for OE.
I wouldn’t try to balance it out by swapping springs, You’ll end up with a mess, after doing all the work of pulling the shocks. A set of springs should cost around $200-300, so do it once and right.
The springs rating in inch pounds relates to the length of the wire and it’s diameter. Surprisingly perhaps, the type of steel they are made from doesn’t make a huge difference. If you plug the numbers out of the manual for a stock E Type spring into an online spring calculator it is a 250 inch pound spring more or less. The height the spring is manufactured to is critical - a 250 pound spring of any height will drop the same X inches with a say 350 pound load (say the back end of the car weighs 1400 pounds by 4 springs). So how high the car sits first depends on the static height the spring is made to.
According to one manual I have the late 3.8 and 4.2 springs were 10.5" tall, 10 coils with closed and ground ends, and .432 wire dia. they are 2.5" inside diameter. A spring calculator is here, along with a description for counting the number of active coils. I believe the stock coil has 10 coils of which 8 are active coils - https://www.thespringstore.com/compression-spring-measurements.html
There has been considerable problems with obtaining new springs that are identical to the old ones, hence ride height problems - the usual complaint is the rear sits too high. Springs sag over the years. I’m told that does nor affect the spring rate - that is they don’t get softer. If you have adjustable shocks I wouldn’t buy new springs . The spring perch on the adjustable shocks is usually a bit higher than the stock shock which will exacerbate the ride height issue with new springs - if it’s too high you can’t get it down. I’ve got this issue on one of my cars.
These guys sell 2.5” ID springs in just about any free length and stiffness you can imagine.
If I’m not mistaken, they are the spring supplier Gaz uses…they are certainly the spring supplier Leda used to use, before that company effectively dissolved, and the refugee engineers went on to start Gaz.
https://dfaulknersprings.com/product-category/standard-springs/2-5-inch-id-standard-springs/