Skyrovers recipe for a smooth quiet Defender.

[skyrover]

A lot of people dismiss the idea of a refined Defender, because in stock form it has multiple compromises geared toward load carrying, towing, fuel economy and price.

I am going to compile a list of things you can do to refine the ride in your Defender, starting from the cheapest to the most expensive along with a description what the ingrediant will do for your car.

Rubber Spring Isolators

Placed at the top, bottom, or both on your springs... these pads will help reduce vibration and noise transmitting through the steel coils of your suspension and into the bodywork of the truck. They will also provide a slight lift in ride height.

Part No: ANR 2938

Cost: £11.95 per pair

http://www.ebay.co.uk/itm/LAND-ROVER-DISCOVERY-1-2...

Note: These will not fit the rear springs on a Defender 110/130

Engine Sound deadening mat

Diesel powered defenders are one of the worst culprits for noise and harshness. Much of that noise passes up through the bonnet and into the cabin via the firewall and windshield. A dedicated engine blanket will block much of this noise.

Cost: £55.00–£95.00

http://www.nkgroup.co.uk/product/vehicle-acoustic-...

Discovery Springs

Standard Defender springs are very much set up for heavy load carrying at the expense of domestic/leisurely driving and even compromise it's off-road ability somewhat due to the lack of flex.
One of the easiest modifications an owner can do is to change the suspension for something more compliant.
Owners of Defender 90 type models can simply swap their springs for those fitted to the original Discovery which have much lower spring rates, despite the Discovery outweighing the Defender 90 by several hundred kilograms. There will be an increase in body roll as a result, so ensure your Defender is equipped with anti-roll bars. These are available through the aftermarket or second hand on ebay.

Defender 90 Part No:

Front: NRC2119 (150lb/inch) £13.20

http://www.paddockspares.com/nrc2119-front-coil-sp...

Rear: NRC8044 (155-215lb/inch progressive) £16.15

http://www.paddockspares.com/nrc8044-110in-driver-...


The Defender 110/130 is slightly more complex as the rear springs are larger and unique, thus lowering your choices. My preferred choice is to install the softer of the two options and fit air helper springs inside for heavier loads.

Defender 110 Part No:

Front: NRC8044 (155-215lb/inch progressive) £16.15

http://www.paddockspares.com/nrc8044-110in-driver-...

Rear: NRC6388 (180lb/inch) £18.60

http://www.paddockspares.com/nrc6388-110in-drivers...

Air helper springs £106.80

http://www.flatdoguk.com/air-lift-adjustable-air-h...

Land Rover Spring rates and part numbers

http://www.red90.ca/rovers/springinfo.html


Soundproofing kit

One of the best ways to reduce the vibrations of the Defender's drum like bodywork is to fit a full soundproofing kit, thus helping insulate the passenger compartment while reducing vibrations and ambient noise. Noisekiller provide a full kit with optional engine blanket.

Cost: £275.00–£475.00

http://www.nkgroup.co.uk/product/full-land-rover-s...


Discovery Transfer case

Defenders share the same transfer case as Discoveries, however the gearing on the Defender is shorter (1:4) which aids towing and offroad at the expense of highway cruising. If your truck is going to be spending the majority of the time on the tarmac, a relatively simple swap is to fit a Discovery transfer case which has taller 1:2 gearing. Alternatively you can have your transfer case sent to ashcroft engineering to be re-geared.
Land rover also produced a set of gears called "q-gears" which stands for "quiet". These were fitted to many discovery 2 models as the Discovery moved upmarket and needed a more refined ride. The angle on the teeth on the gears is changed for a more quiet operation. Ashcroft can fit these "quiet" gears on request.

Cost: £495.00+ for ashcroft rebuild plus fitting. Second hand boxes are cheaper on ebay.

http://www.ashcroft-transmissions.co.uk/transfer-b...

Air Suspension

For the ultimate in luxury, air suspension kt's are increasingly available these days' for Defender's offering Range Rover levels of ride comfort.

http://www.neneoverland.co.uk/nene-news/we-now-off...

http://www.marantdesign.co.uk/

Cost £2000+

Automatic Gearbox

Becoming and increasingly common swap, removing the heavy clutch and short gearing can make the Defender much more driveable around town and better for towing heavy loads smoothly.

Cost: £2300+

http://www.ashcroft-transmissions.co.uk/defender-a...

Petrol Engine

Lastly if you want a truly great car, my advice would be to throw away the biggest Achilles heal of the Defender.. it's powerplant, and fit a smooth, reliable and effortless petrol engine such as an LS Chevrolet V8.

Marks adapters in Australia make kits to bolt Chevy V8's into Land Rover's

http://www.marks4wd.com/engine-conversions/bell-ho...

Cost: £800+ plus the engine.

Edited by skyrover on Wednesday 10th August 15:59

[300bhp/ton]

Good info.




Couple of points. The rubber spring isolators I think should be present as standard on a Defender. Although may be worn or missing.

The Low Range gearing of the 1.4 and 1.2 transfer boxes are the same. So there is no off road advantage with the Defender transfer box.

And overall gearing, as in mph per 1000rpm in top is actually quite similar if you have a Defender on standard 31-32" tyres and a Discovery on standard 29" tyres.

Fitting the 1.2:1 to a Defender on 32" tyres will indeed lower cruising rpms. But will also likely blunt acceleration and in-gear performance. A standard Tdi or older motor may not like pulling the taller gearing either. Even a stock non tuned Td5 might grumble at motorway speeds, forcing you to downshift where previously you wouldn't have had too.



Sound proofing and making sure all the door seals, vent seals, etc are actually sealing will make a big difference.

[skyrover]

Haven't come across a spring isolator on a Defender before... then again I've never owned one newer than a 300tdi so thanks for the info.

Agreed about the doors... amazing how many are not adjusted properly, thus letting in noise (and rain)

My sister is running 265/75 r16 cooper ATR's on a 1:2 transfer case in her little 90 and it's made a big difference to highway refinement, but yes, I find it does tend to need a downshift on steep hill's now when towing a trailer that it did not before.

Honestly I found the gearing much too short with the 1:4, first gear was only needed when towing heavy loads... otherwise she just used 2nd to pull away.

This is on a 1989 90 with a disco 200tdi swapped in.

Edited by skyrover on Wednesday 10th August 16:00

[Andy_mr2sc]

Out of interest is the nkgroup soundproof kit the definitive kit of choice for defenders? I've been looking at various kits at various prices and want to choose the right one that does the best job.
Very interesting reading btw. I'm putting new axles/springs/dampers/bushes/ball joints etc on my 90 next week and I'm now going to get some rubber Spring isolators to help with the nvh.

[300bhp/ton]

Andy_mr2sc said:

Out of interest is the nkgroup soundproof kit the definitive kit of choice for defenders? I've been looking at various kits at various prices and want to choose the right one that does the best job.

There probably isn't a definitive.

Biggest issue is, most people are only likely to buy or experience one setup. And even if they sample other LR's with other sound proofing kits, there is nothing to say the other parts on the vehicle (engine, tyres, condition, gearing etc) would be the same for a direct comparison.

[skyrover]

300bhp/ton said:

Andy_mr2sc said:

Out of interest is the nkgroup soundproof kit the definitive kit of choice for defenders? I've been looking at various kits at various prices and want to choose the right one that does the best job.

There probably isn't a definitive.

Biggest issue is, most people are only likely to buy or experience one setup. And even if they sample other LR's with other sound proofing kits, there is nothing to say the other parts on the vehicle (engine, tyres, condition, gearing etc) would be the same for a direct comparison.

Pretty much this...

I've heard good things about the NK soundproofing kit... feedback is that it works well so you should expect a noticeable difference.