Cheap Series Spring Mods for Increased Wheel Travel

[ISUZUROVER]

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.

[ISUZUROVER]

And now the flex pics (actually driving not ramp posing). It has about 14.5" of front and 15" of rear travel. The travel is not huge by tuff truck standards but is nicely balanced. The front travel is limited by the military shocks (so longer shocks would give more flex. In the rear the travel is limited by the spring rate (when the rear is unladen). The rangie shocks can still allow a bit more down-travel in the rear.

[Tim D]

My brother used standard s2A ex army springs(about 69 model) on his stage one ex army(modified 2 into one) and it had lots of travel, maybe not as much as yours, i'll look around and try to find some pics.

[Tim D]

hope this works.
http://www.goldcoast4wdclub.org.au/gallery/album01/aae

[ISUZUROVER]

Hi Tim, I spoke to your brother at Gatton on a past event that my club ran when he had first built it. It is a nice truck. Do you have pictures of the caliper mounts on the swivels?

[GURU]

I'm going to fit coils to mine

alot more work but will be worth it

["CANADA"]

Again if you have these, taper the leaves.

what do you mean when you say put a taper on them?

[the_grubb]

......the caliper mounts on the swivels?

Is this the disc brake conversion using the Valiant calipers?

[ISUZUROVER]

Again if you have these, taper the leaves.

what do you mean when you say put a taper on them?

There are 2 types of leaf cut - straight cut leaves (like Land Rover uses) and tapered or chamfered leaves. The latter are better. I only put a small taper/chamfer in mine, to put a bigger one you would need to move the clamps further inboard from the leaf ends.

[ISUZUROVER]

......the caliper mounts on the swivels?

Is this the disc brake conversion using the Valiant calipers?

No, this uses std RR/110 calipers. The normal mounting bracket is removed from the Rangie caliper, and the caliper end bolts are used to mount the caliper to a 2-piece bracket that attaches to the top and bottom swivel bolts.

[Tim D]

Hi Tim, I spoke to your brother at Gatton on a past event that my club ran when he had first built it. It is a nice truck. Do you have pictures of the caliper mounts on the swivels?

If i remember i'll take a pic for ya, and here is what he has done with the car since then.

Its injected and super charged with rangie axles and lockable know, owh yeah centre mounted winch(pto)

[Tojo]

thats a nice looking landy!

[Tim D]

Hi Tim, I spoke to your brother at Gatton on a past event that my club ran when he had first built it. It is a nice truck. Do you have pictures of the caliper mounts on the swivels?

You may have to tilt your head to see these pics i took of the front brakes, stupidly forgot completly about the back, i think the front was harder than the rear. For more detail and problems with doing this i can ask my brother to do a post on the matter.

[ISUZUROVER]

Cheers Tim. Pics of the back aren't really necessary, that is pretty simple, but some pics of the brakes with the wheel off would be cool. And a description of what bolts were used for the swivels? Were they drilled and tapped to a different thread?

[Tim D]

My brother could answer thosen questions, from memmory he did the design off the side-winder, will try and get another pic for you soon.

[andrew e]

I'm going to fit coils to mine

alot more work but will be worth it

i have a spare rangie chassis with the front body mounts already modified for a 2a firewall, you can have it for a carton of extra dry if you want.

Andrew.

[ISUZUROVER]

My brother could answer thosen questions, from memmory he did the design off the side-winder, will try and get another pic for you soon.

From memory I think your brother copied the design from a similar setup built by a mate of mine (ralph) which he sold to another mate (mick - bobtail on here) and which mick later sold. The only difference that I can see is that Ralph made longer studs for the swivels rather than using bolts. Would be interesting to know what bolts your brother used (i.e. same thread as original studs or different).