Rocky Mountain Parabolic Springs are manufactured to ISO  standards. These rugged springs have advanced design features perfected over many years of supplying parabolic springs to leading truck manufacturers. The individual spring leaves are tapered, heat treated, and stress peaned under load for increased strength. Bending stresses in the material are evenly distributed along the length of the leaf. There is generous contact area on all wear points, and stresses caused by drilling are minimised by having the guide straps positioned near the end of the leaves. The clamp area under the axles is kept absolutely flat to prevent pre-load. Spring bushings are a full 1¼ inches diameter for greater flexibility and this increased curvature reduces stress in the spring eyes. Springs are supplied in pairs and packaged with correct ‘U’ bolts, nuts and washers needed to complete the installation.
Fitting ‘Rocky Mountain’ parabolic springs will raise the loaded ride height of your Land Rover by at least one to two inches when compared to stock springs.
The use of extended shackles to raise the ride height further may create stability problems and drive line problems and is not recommended. Where extended shackles are used (as in military Land Rovers) the extended axle buffer mounting must be retained to prevent over-stressing the springs in maximum compression.

NB: Fitting extended shackles without extending axle buffer mountings will invalidate your warranty.

PARABOLIC SPRINGS will make a very significant improvement to your Land Rover and are probably the greatest single modification worth making to enhance enjoyment of the truck for you and your passengers.
Please take a moment to read the notes explaining the advantages and disadvantages of each of the spring sets in our range. If you have any further questions please contact us directly.

Front Springs 73588: All Purpose (Two Leaf)

73588 are front springs used on all models. These springs have two parabolic leaves with a military wrap on the second leaf. Like all Rocky Mountain springs they are supplied with a matching set of ‘U’ bolts designed to fit the Rover axle.

The length of these springs is carefully controlled to allow the shackles exactly the right amount of slant aft maximizing the range of travel on the spring in both directions.

Rear Springs 73589: Two Leaf

73589 are medium duty rear springs with two parabolic leaves, used on SWB models where softer ride and maximum axle articulation are desired.  Clips positioned at the eyes prevent leaf distortion at maximum articluation. An additional pad under the lower leaf reinforces the assembly. These springs do not preclude you carrying heavier loads but you have to accept that the rear of the truck will deflect more when such loads are carried.  These springs suit the majority of SWB trucks.

CAUTION: You should not use these springs if you use your Land Rover for towing a heavy trailer regulary.  You should consider three leaf rears for these applications.

Rear Springs 73590: Three Leaf

73590 are heavy duty three leaf parabolic springs. If you often load your SWB to the maximum rated load, use these springs. Also use 73590 on stock LWB trucks that are used for general utility.

On SWB  models the 73590 spring is the correct choice if you  use a roof rack, or tow a heavy trailer.
If your standard ‘109’ has a heavy custom camper conversion or other heavy modification to the load area then you may require a ‘73591’ fourth leaf spring addition.

Rear Springs 73591: Fourth Leaf Kit
73591 are heavy duty fourth leaf rear springs to be added on LWB models where heavy loading is normal. These springs are also usually fitted if you plan an expedition or have fitted a camper conversion on your regular ‘109′ or any other heavy modification to the load area.

This illustration is of a 4th leaf kit (73591) already fitted to a 3-leaf spring (73590)

CAUTION:If these springs are fitted to a lighter ‘109′ such as a canvas topped or pickup cab model, the 73591 springs will raise the unloaded bed height to the extent that modifications to the shock absorber mountings will be needed.
Parabolic springs may not be the best choice on the rear of a Land Rover such as a canvas topped or truck cab model if you want to load the truck to it’s maximum rated capacity. The range or loads applied extends and compresses the supple Parabolic spring beyond the range of any shock absorber that can be fitted to the normal shock absorber mountings.