Cheap Series Spring Mods for Increased Wheel Travel
Posted: Thu Feb 24, 2005 8:11 pm
Now that pics are back I thought I would post up a thread on improving series wheel travel - and what I did to mine.
Front.
The best front springs are the std 9leaf SWB petrol springs (200lb/in) - these have one 4.4mm main leaf and 8 4.2mm leaves - it is hard to find a good second hand set. They will work on all LR's except a 3.9 ISUZU. If you have these springs just cut a taper in the leaves, smooth up the edges and that is all. I didn't have these so I bought after market SWB petrol spings that have 9x5mm leaves so the rate is 315lb/in!!! - I removed 3 leaves (so now 6), tapered and smoothed the edges and had them reset to about 11" free camber (drivers) and 10.5" passenger. If you have a military LR, remove the bump stop spacer but retain the std shock. If you have a civilian LR, you can usually get a lot more up-travel than the bump stop will allow. I know people who have cut the bump stop in half, but you can also relocate the shock mount higher and fit longer shocks.
Rear.
For a SWB - again the std factory leaves are best - should be 11x4.4 (longer leaves have a lower spring rate) with a rate of 160lb/in. Again if you have these, taper the leaves.
For a LWB - you want a rate of about 270lb/in. I had std military 8x7.1mm springs, which are 400lb/in. (S3 9x7.1mm are 500lb/in!!!). I removed 3 leaves (now 5), cut the rest down to an even spacing and tapered them (if you want you can make them dual rate if you want (see below)). And had them reset to about 14" drivers side and 12" passenger. All it cost me was $60 a pair to reset - make sure they temper them after resetting. They will settle a bit after you have them on the truck, that is why the free camber is so high. You could go a bit softer but 270lb/in still lets me carry a decent load as well.
For a military truck, leave the rear bump stop spacer in and fit Range Rover rear shocks. For a civilian, RR shocks would work as well but you need to raise the shock mount (and have to cut a hole in the floor for space).
You will get increased on road comfort with this setup, and more body roll, but the truck is just as stable when cornering, and you get used to the body roll. If you have an engineering background, grab a book called the "leaf spring design manual" by the SAE. It is what I used. But if you just follow the steps above you won't need it.
I did these mods back in 1997 and the landie has been used extensively on and off road ever since (average 10000km/yr, and 4x4ing most weekends). The springs have performed perfectly, and have not sagged. Note that the rear clamps are far too long in the pictures (pics were taken before trimming) - Bolt up clamps are better than the wrap-around type as they allow the leaves to separate.
Front.
The best front springs are the std 9leaf SWB petrol springs (200lb/in) - these have one 4.4mm main leaf and 8 4.2mm leaves - it is hard to find a good second hand set. They will work on all LR's except a 3.9 ISUZU. If you have these springs just cut a taper in the leaves, smooth up the edges and that is all. I didn't have these so I bought after market SWB petrol spings that have 9x5mm leaves so the rate is 315lb/in!!! - I removed 3 leaves (so now 6), tapered and smoothed the edges and had them reset to about 11" free camber (drivers) and 10.5" passenger. If you have a military LR, remove the bump stop spacer but retain the std shock. If you have a civilian LR, you can usually get a lot more up-travel than the bump stop will allow. I know people who have cut the bump stop in half, but you can also relocate the shock mount higher and fit longer shocks.
Rear.
For a SWB - again the std factory leaves are best - should be 11x4.4 (longer leaves have a lower spring rate) with a rate of 160lb/in. Again if you have these, taper the leaves.
For a LWB - you want a rate of about 270lb/in. I had std military 8x7.1mm springs, which are 400lb/in. (S3 9x7.1mm are 500lb/in!!!). I removed 3 leaves (now 5), cut the rest down to an even spacing and tapered them (if you want you can make them dual rate if you want (see below)). And had them reset to about 14" drivers side and 12" passenger. All it cost me was $60 a pair to reset - make sure they temper them after resetting. They will settle a bit after you have them on the truck, that is why the free camber is so high. You could go a bit softer but 270lb/in still lets me carry a decent load as well.
For a military truck, leave the rear bump stop spacer in and fit Range Rover rear shocks. For a civilian, RR shocks would work as well but you need to raise the shock mount (and have to cut a hole in the floor for space).
You will get increased on road comfort with this setup, and more body roll, but the truck is just as stable when cornering, and you get used to the body roll. If you have an engineering background, grab a book called the "leaf spring design manual" by the SAE. It is what I used. But if you just follow the steps above you won't need it.
I did these mods back in 1997 and the landie has been used extensively on and off road ever since (average 10000km/yr, and 4x4ing most weekends). The springs have performed perfectly, and have not sagged. Note that the rear clamps are far too long in the pictures (pics were taken before trimming) - Bolt up clamps are better than the wrap-around type as they allow the leaves to separate.
