disco suspension mods, status report

OK, for those who don't know WTF I'm on about...

On my disco the rear springs were naff, and the newly-fitted (and expensive)
alloy petrol tank looked rather closer to the ground than I liked. Also the
handling was a bit softer than my preference... what I wanted was about 1"
lift and about 10% stiffer springs...

study of spring rates soon decided that there were many options for the
front end, this being a V8. In the end I settled on NRC2119 (partly 'cos it
was what I wanted and partly 'cos Paddock had 'em going cheap). They're
diesel spec RR/disco front. There is, too, a taller/stronger one which I
assume to be HD diesel spec.

Back ones presented more of a challenge, not least 'cos of a lack of
accurate info as to what's actually fitted to the disco rear as standard.
In the end I went for the highest-rated standard rear springs I could see in
the list, which are D90 HD rears, RKB101230 and RKB101240. These turn out
to be about the same height as the disco rears, but I suspect still slightly
stiffer. They're dual-rate, while the ones that came off my disco *may* be
dual or variable-rate - the wire diameter appears to taper towards one end
of the spring.

half a days graft with the spring compressors and other stuff got 'em
fitted. The front end sat nicely about an inch higher than standard, as
planned. The rear, although it felt more taut and "springy" was about at
standard height still. To cure this, I made up spacers for the rear axle,
which give the desired 1" lift. These are in the form of a solid disc just
under 110 mm diameter and 25ish mm thick. The top surface has been machined
to mate with the bottom of the spring cup, which has a hole in the middle.
Somewhat to my surprise, there's no corresponding shape on the axle for the
cup to locate on (once you remove all the rust and crap) so the bottom
surface of the spacer is simply flat. the 2 bolts which hold the spring and
cup down were changed for longer ones which now go through the spacer as
well.


So. was it all worth it? well, I reckon so. The vehicle sits nicely level
and about an inch higher than standard, as I wanted, and feels a lot more
positive on the road. This one has a front ARB, which does a better job of
controlling roll than the rear one which is fitted to the other disco, but
it was still soft and rolly on the road. The steering is a tad lighter,
probably due to having marginally less castor angle due to the suspension
design - the more you lift the suspension, the less castor angle you get -
I've seen "corrected" swivels for sale for things with more extreme lift,
but I don't think for a 1" lift that they're necessary.

Downsides? It's lost about an inch of suspension travel (which could be
regained by fitting different turrets/rear damper mounts or longer dampers),
but for almost all the use I put the vehicle to that's irrelevant. The only
other thing is the lightness of the steering, but it's not so light as to be
uncontrollable and you get used to it.

--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
"Quos deus vult perdere, prius dementat" Euripedes, quoted in
Boswell's "Johnson".

Austin Shackles vaguely muttered something like ...

> So. was it all worth it? well, I reckon so. The vehicle sits nicely
> level and about an inch higher than standard, as I wanted, and feels a
> lot more positive on the road. This one has a front ARB, which does a
> better job of controlling roll than the rear one which is fitted to the
> other disco, but it was still soft and rolly on the road. The steering
> is a tad lighter, probably due to having marginally less castor angle due
> to the suspension design - the more you lift the suspension, the less
> castor angle you get - I've seen "corrected" swivels for sale for things
> with more extreme lift, but I don't think for a 1" lift that they're
> necessary.
>
> Downsides? It's lost about an inch of suspension travel (which could be
> regained by fitting different turrets/rear damper mounts or longer
> dampers), but for almost all the use I put the vehicle to that's
> irrelevant. The only other thing is the lightness of the steering, but
> it's not so light as to be uncontrollable and you get used to it.

Sounds good ..

We just got back from a week in Scarborough, so 'played' a little in
Langdale Forest .. Borrowed a little Suzuki SJ 413 for an hour first to
'have a look' and was amazed at what it could do. Anyway, our Disco ('96
300 Tdi) was brilliant, just as good (better actually) as the Suzuki, but
with comfort too, but I feel we need just a little more height occasionally.
We go loaded with wife and two kids when we go off-road, so ride height is a
little compromised. 1" lift would be about right we reckon, as we already
have slightly taller (31 x 105 BFG AT') tyres and the wife seems to think we
have the budget for it ..

--
Paul ...

(8(|) ... Homer Rocks

"A tosser is a tosser, no matter what mode of transport they're using."

On or around Sat, 21 Aug 2004 13:32:58 +0100, "Paul - xxx"
<[email protected]> enlightened us thusly:

>Austin Shackles vaguely muttered something like ...
>
>> So. was it all worth it? well, I reckon so. The vehicle sits nicely
>> level and about an inch higher than standard, as I wanted, and feels a
>> lot more positive on the road. This one has a front ARB, which does a
>> better job of controlling roll than the rear one which is fitted to the
>> other disco, but it was still soft and rolly on the road. The steering
>> is a tad lighter, probably due to having marginally less castor angle due
>> to the suspension design - the more you lift the suspension, the less
>> castor angle you get - I've seen "corrected" swivels for sale for things
>> with more extreme lift, but I don't think for a 1" lift that they're
>> necessary.
>>
>> Downsides? It's lost about an inch of suspension travel (which could be
>> regained by fitting different turrets/rear damper mounts or longer
>> dampers), but for almost all the use I put the vehicle to that's
>> irrelevant. The only other thing is the lightness of the steering, but
>> it's not so light as to be uncontrollable and you get used to it.
>
>Sounds good ..
>
>We just got back from a week in Scarborough, so 'played' a little in
>Langdale Forest .. Borrowed a little Suzuki SJ 413 for an hour first to
>'have a look' and was amazed at what it could do. Anyway, our Disco ('96
>300 Tdi) was brilliant, just as good (better actually) as the Suzuki, but
>with comfort too, but I feel we need just a little more height occasionally.
>We go loaded with wife and two kids when we go off-road, so ride height is a
>little compromised. 1" lift would be about right we reckon, as we already
>have slightly taller (31 x 105 BFG AT') tyres and the wife seems to think we
>have the budget for it ..

The best bit about it is that the springs, being standard, are cheap. If
you're equipped (or know someone who is) to make the spacers, they're an
easy job on a lathe. what I did was to buy approx 27mm slices off a 110mm
round bar from the local purveyor of big lumps of steel, put one up on the
lathe and face it one side, switch it round and face down to a 2" (iirc,
CHECK FIRST) diameter on the other side. The inside of the spring seat
(underneath) is about 110mm diameter, once you clean all the crap and rust
out - if necessary, you can always turn it down slightly if it won't fit.
The 2" diameter by about 2mm high spigot that results locates nicely in the
hole in the middle of the spring seat, then you mark the positions for the 2
boltholes, and drill 'em (10.5mm in my case, to allow easy clearance for the
10mm bolts. I think you'll find that M10x50mm bolts are a suitable size to
replace the existing short ones (which I think are M10x30 and too long,
bloody idiots LR. - like the M6 ones that hold the middle row seats into the
disco - freakin' things protrude underneath by a good 15mm, go rusty and are
a sod to remove. one bugger sheared, of course, so fun and games to replace
it (or just use 3 bolts...)

I guess if you were feeling keen, the spacer could be drilled some more to
add more lightness, although given the weight of a disco rear axle the extra
weight of 2x110x25mm steel is a pretty minor aspect.

--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
In Touch: Get in touch with yourself by touching yourself.
If somebody is watching, stop touching yourself.
from the Little Book of Complete B***ocks by Alistair Beaton.

Austin Shackles vaguely muttered something like ...
> On or around Sat, 21 Aug 2004 13:32:58 +0100, "Paul - xxx"
> <[email protected]> enlightened us thusly:
>
>> Austin Shackles vaguely muttered something like ...
>>
>>> So. was it all worth it? well, I reckon so. The vehicle sits nicely
>>> level and about an inch higher than standard, as I wanted, and feels a
>>> lot more positive on the road. This one has a front ARB, which does a
>>> better job of controlling roll than the rear one which is fitted to the
>>> other disco, but it was still soft and rolly on the road. The steering
>>> is a tad lighter, probably due to having marginally less castor angle
>>> due to the suspension design - the more you lift the suspension, the
>>> less castor angle you get - I've seen "corrected" swivels for sale for
>>> things with more extreme lift, but I don't think for a 1" lift that
>>> they're necessary.
>>>
>>> Downsides? It's lost about an inch of suspension travel (which could be
>>> regained by fitting different turrets/rear damper mounts or longer
>>> dampers), but for almost all the use I put the vehicle to that's
>>> irrelevant. The only other thing is the lightness of the steering, but
>>> it's not so light as to be uncontrollable and you get used to it.
>>
>> Sounds good ..
>>
>> We just got back from a week in Scarborough, so 'played' a little in
>> Langdale Forest .. Borrowed a little Suzuki SJ 413 for an hour first
>> to 'have a look' and was amazed at what it could do. Anyway, our Disco
>> ('96 300 Tdi) was brilliant, just as good (better actually) as the
>> Suzuki, but with comfort too, but I feel we need just a little more
>> height occasionally. We go loaded with wife and two kids when we go
>> off-road, so ride height is a little compromised. 1" lift would be
>> about right we reckon, as we already have slightly taller (31 x 105 BFG
>> AT') tyres and the wife seems to think we have the budget for it ..
>
> The best bit about it is that the springs, being standard, are cheap. If
> you're equipped (or know someone who is) to make the spacers, they're an
> easy job on a lathe. what I did was to buy approx 27mm slices off a 110mm
> round bar from the local purveyor of big lumps of steel, put one up on the
> lathe and face it one side, switch it round and face down to a 2" (iirc,
> CHECK FIRST) diameter on the other side. The inside of the spring seat
> (underneath) is about 110mm diameter, once you clean all the crap and rust
> out - if necessary, you can always turn it down slightly if it won't fit.
> The 2" diameter by about 2mm high spigot that results locates nicely in
> the hole in the middle of the spring seat, then you mark the positions
> for the 2 boltholes, and drill 'em (10.5mm in my case, to allow easy
> clearance for the 10mm bolts. I think you'll find that M10x50mm bolts
> are a suitable size to replace the existing short ones (which I think are
> M10x30 and too long, bloody idiots LR. - like the M6 ones that hold the
> middle row seats into the disco - freakin' things protrude underneath by
> a good 15mm, go rusty and are a sod to remove. one bugger sheared, of
> course, so fun and games to replace it (or just use 3 bolts...)
>
> I guess if you were feeling keen, the spacer could be drilled some more to
> add more lightness, although given the weight of a disco rear axle the
> extra weight of 2x110x25mm steel is a pretty minor aspect.

My brother works at the local metal fabrication/small engineering works as a
welder .. hmmm ... I think a plan is forming.

Many thanks for the further detail ..


--
Paul ...

(8(|) ... Homer Rocks

"A tosser is a tosser, no matter what mode of transport they're using."