RRC police/military spec springs comparison

Hi everyone, I've been looking at sourcing some HD srpings for my disco 1 as it's regularly laden down by a certain amount.

At the moment it's on standard springs (I have to assume) which are a bit tired and I've fitted a slightly shorted brownchurch rack from a 110, and have a poly 62 litre veg oil tank installed in the boot. Given that those two things alone weigh in the region of 85-90kg (with oil in the tank at least), it's understandable that it's sagging a bit. Add in the driver (85kg) and the dog in the boot (35kg) plus any drums of oil that I'm carting around and it's regularly overloaded... :scratching_chin:

So, looking at HD springs then - I don't want a 2" lift as I discussed in a previous thread, mainly becuase of the extra stuff that goes on the roof rack when I load up for trips away with the family. I've been looking at Range Rover police and military spec springs, namely NRC4304 and ANR4491. Looking at the specs from the comparison charts, NRC4304 (Red-White marked) has a higher load carrying capacity but lower spring rate than ANR4491 (988.88lbs & 285.5lbs/inch) while the standard springs are in between the two of these two spring rates with a lower carrying capacity.

• Police spec (Red+White) NRC4304 - 1106.06lbs & 170.0lbs/inch
• Military Spec (Brown-Grey) ANR4491 - 988.88lbs & 285.5lbs/inch
• Disco Standard (Brown-Green) - 754.94lbs & 207.8lbs/inch

So what should I opt for out of these two if I don't go down the Britpart/Bearmach/OME/Terrafirma etc HD springs route?




If I go for the higher capacity of the police springs, should I look to upgrade my dampers to try to even out the soft spring rate?

Forget 'police spec' springs they are progressive springs for the RRC which has the Borge strut SLS.

Standard D1 springs are hard-ish to start with, but if u think the weight u are carrying will exceed the spec of the standard spring then go for the disco HD or even harder Military Spec springs and then feel every bump.

Did the military ever use discos?

Yes, all three services had them and still do albeit 3s and 4s now.

Hmm... I cant remember where I read it now but was sure that NRC4304's were for RR without the leveling system? Might have that wrong, but I thought there was another spring that was used in that application.
As for exceeding the capacity of standard springs, I think I'm already at that point before I start loading up with kids and camping gear - I normally take 100 litres of veg oil on a trip so that and the roof rack alone is an extra 135kg(300lbs) without driver or passengers.

No idea if the military used discos or not, but LR springs are universal fit except for 110 rears. Whether or not they're correctly matched to the vehicle application is a different matter..

you could do worse than buying britpart yellow std height hd springs ,not expensive

Yeah have been looking at those too, but must admit I like the insurance friendly idea of lr part numbered springs, even though they may not be lr made.

And yes, they are pretty cheap too which I'm always a fan of

i used them on my disco 1 was a harder ride but handled better and carried more weight

I know Paul had them on his disco with good results, but they get very mixed reviews on reliability, but then as they're so cheap if they say after a couple years they can be cheaply replaced anyway I guess ��

The max I've ever had in my boot is 20 packs of beer in the days of cross channel "booze cruise " which was around 110kg plus a other few bits and bobs so easy 130kg plus me and a passenger, and my disco was really iffy at the roundabouts on the way home
So u are looking a HD but then if u have ever seen police D1 discos they were always down at the back and no doubt HDs were fitted as standard at the factory.

I popped the police spec ones in my 300 tdi auto, when empty the back end tended to bounce a bit. However with two canoes on the roof, two kids in the back and two weeks worth of camping gear and holiday gear touching the roof in the back it was brilliant. I am about to order them again for my 200tdi.
Just checked the part number...ANR 4491...

Well as it turns out I went to look at some springs from ebay that were just down the road from me, and the guy did me a very good deal after we identified the rear springs as ANR4491 military spec springs.

These have the same spring rate as britpart HD yellow springs, but I cant seem to find the load carrying capacity of the yellows - anyone know what it is?

Anyhow the rears are fitted now and the rear end is back up and level again after gaining just over an inch. I'm not sure what spec the old springs were because ironically some idiot painted them yellow! I think they must have been uprated, but by now they're just tired.

Now I've done that it just shows up the dampers, they need replacing now too - it never ends does it?!

Forgot to say the ride is great with them on - flat in the corners and firm but not bouncy, as as I said in my first post even when the disco is empty I'm still carrying 80-90 kg more than a standard empty disco, so no wonder really

Just need to try it fully laden now...