by Ken Gillanders
We get a regular stream of inquiries relative to springs and handling on TRs. One thing we’ve learned is that there are a lot of misconceptions about the effect of springs, people sometimes equating springs alone to the ride and handling quality of their cars. Several have gone out and bought new high-performance springs, without giving any additional consideration to shocks or the idea of sway bars. The result is often a TR that looks more like a monster truck than a sports car and has all the attendant handling side-effects.
Rear Springs
If you break a rear leaf spring, I suggest you try finding a good used one. It will have about the same strength and set as your original, much more so than buying a new one, and should give you the same ride height. If for some reason you want to replace both leaf springs with new ones, you should carefully inspect the new ones first. If they look like the mouth of a "happy face", the rear of the car will probably be about 4" higher off the ground and it will look like it’s perpetually going down a steep hill. Probably it would be better to take your original springs to a good spring rebuilder, along with a photocopy of the drawing on Page 3 of Section "H" in the TR2/3 Workshop Manual. If you want a bit more strength you can have the rebuilder add an extra leaf, although he will probably have to re-arch the spring a bit to maintain ride height. You can finish up by replacing the front sping eye ‘silentbloc’ bushing. This should give you what you need in the way of ride height and support. For enhanced handling you can use a rear spring locating kit with stainless steel locating plates, and replace the rubber rear bushings with nylatron.
Front Springs
Unlike the rear springs we just discussed, the front spring situation is going to be a little harder to handle. The fronts are more likely to sag and show their age than the rears, and the variety of replacement stock from the TR suppliers varies widely. I recall springs that were advertised as "original factory competition front springs" which in fact bore no relationship to the genuine items. The supplier did not make the springs, nor did they really know anything about what they had. They believed the firm who supplied the pieces, who themselves did not know the true origin of these particular parts!
So what do we do? Well! Page 1 of Section H of the TR2/3 Workshop Manual certainly gives you all the specifications for the original springs, as well as the factory competition versions. Notice that the competition springs are only 18.5% stronger than standard. There is no good reason to exceed this. While it is not economical to try and have your own springs wound using that data, you will at least be able to recognize the real thing.
Today’s racing practice seems to largely bypass much heavier springs in favor of much stronger and adjustable shocks in the front, and rebuilt and much stronger rear shocks. The race cars use sway bars up to 1" in the front to control body roll. Once the springs and shocks are sorted out, there are other parts available to further enhace the car’s behavior: urethane bushings for the front A-arms and stainless & bronze bushings to replace the old rubber Silentblocs in the steering tie rod. These items will help, but remember that the foundation of the car’s handling and ride is the spring and shock combination, and the end result will only be as good as those components.
While we’re talking about coil springs, there is of course the Independent Rear Suspension setup in the TR4A, 250 and 6 models. This is a whole ‘nother matter and all of its ills will not be cured here. Tired of spring sag? Tired of excessive negative camber? Tired of seasickness? Well, slightly stronger springs will help. However, some of the upgrades I have seen are really UP! The rear of the car is rock solid, we now have positive camber and the rear of the car is about 3" too high! I guess if a little is good, a lot must be better, right? First let’s see if we can get a set of the real original springs, or something a little stronger that fits.
How do you find out how strong any spring is at any fitted length? Most racing shops (stock car or sprint car) have digital readout machines for checking springs. It might cost you a few bucks to have them checked, but it will be well worth it to find out ahead of time if the springs you plan to install are going to be worth the trouble. Be sure to take the original spec data with you to the shop; it will be very useful.