The product background:

One of the more popular upgrades for all Land Rovers are polyurethane bushes, or Polybushes, as they're usually known. 'Polybush' is a bit like Hoover, or Thermos: it's actually a tradename, which has become synonymous with the product, and has been adopted as a noun to describe all products of that type. Not everyone owns a Hoover vacuum-cleaner, but plenty of people 'do the Hoovering…'

There are several different brands of polyurethane bushes available, varying from the very cheap-and-nasty to the 'real' Polybushes. In order of increasing hardness, the scale would range from OEM Land Rover rubber bushes, blue Polybushes, red Polybushes, the yellow Old Man Emu range, Ironman, up to the 'cheap-and-nastys', which are usually the hardest of all.

Considering your vehicle's handling relies a great deal on suspension bushes, I personally wouldn't even consider the cheaper brands, since they're usually very hard and of dubious quality. Whilst the extra hardness might improve the vehicle's handling marginally over another brand, the downside is that the extra 'tightness' will be translated into stresses, which are then transferred to parts of the vehicle Land Rover never intended to take them, which may in time lead to something similar to metal fatigue.

Also, beyond a certain point, the harder the polyurethane used, the more vibration and noise will be transmitted into the vehicle's interior, which is another reason for keeping to the softer ranges of bushes.

There are several very good reasons for the popularity of Polybushes. As with a great many things on all vehicles, the OEM (Original Equipment Manufacturer, i.e. Land Rover) bushes have to be a trade-off, since Land Rover have no idea what you're going to be using the vehicle for. You might do 40,000 miles a year up and down motorways, or spend all day driving off-road, and the vehicle has to be able to do both reasonably well straight out of the showroom.

When choosing and fitting Polybushes, however, you can tailor the bushes to suit the use of your vehicle.

If your priority is on-road performance, then the harder 'red' bushes will improve the vehicle's handling over the standard OEM bushes, as they 'tighten' the vehicle's handling, without making it unduly harsh.

If the vehicle is predominantly used off-road, or off-road performance is of importance, then the softer blue bushes would be a better option. As the blue bushes are actually only marginally harder than Land Rover's rubber ones, they retain the vehicle's axle articulation, but their main advantages are that they're considerably easier to fit, and outlast the standard rubber ones many times over, maintaining their 'feel', and they don't gradually weaken over time like the rubber ones, or just fail without warning.

This is one of the issues with the Land Rover rubber bushes: they can be very short-lived in certain circumstances. As they're made of rubber, and rubber is damaged by oil, and there's usually a fair coating of oil underneath most Land Rovers, this is always going to cause problems sooner or later. The main problem with Land Rover bushes, however, is that they can be very difficult to remove, as an appropriately-sized drift and a hydraulic press are invariably required (unless you buy a Bushwacka tool from Polybush!)

Sometimes people in Land Rover magazines suggest burning the rubber bushes out, which is doubtless one solution for problem bushes, but I wouldn't fancy it personally. Firstly the smell will be awful, and secondly I suspect that burning bush-rubber would be like Napalm, if you were unlucky or careless enough to get the stuff near you.

The bushes:

Although the majority of the bushes on my vehicle were OK, as some were replaced very recently, I decided to replace them with Polybushes nonetheless, to see whether the extra firmness of the polyurethane bushes would improve the vehicle's handling, and to see if the Polybushes would last longer.

As Camel Trophy Discoverys weigh considerably more than the standard Discoverys and also have a somewhat strange weight distribution because of the winch/bullbar/steering guard assembly and the heavy roofrack, they place a lot of extra strain on all the suspension components, and consequently the handling suffers.

The other reason behind the change was to remove the likelihood of rubber-bush failure, as when my radius arm bushes were replaced, one bush failed within a month, which was disappointing after such a short length of time, making the handling distinctly unpleasant until it was replaced for the second time.

I ordered a 'hybrid' set of proper Polybushes directly from Polybush in Wrexham, comprising of a complete set (radius arms, and panhard rods) of the harder red bushes, apart from the chassis-ends of the radius arms, which I wanted to be the softer blue compound, in order to maintain the axle articulation when off-roading.

I also decided to replace the rear axle A-frame balljoint bushes with red Polybushes as well, as this area is a notorious weak point on Land Rovers.

The bushes come packed in a large cardboard box, with each type of bush in a separate polythene bag, stating where it goes, and how many bushes it will replace: "Rear radius arm to chassis. Contents will bush the chassis end of 2 radius arms." Instructions don't get a lot clearer than that!

Fitting:

The general rule is that the bushes at the chassis ends are just pulled off by hand; the axle ends need pressing out.

As the front radius-arm bushes had only been in there a year or so, they weren't actually too bad to remove, all things considered. Basically, the radius arms were removed from the vehicle one at a time, supported underneath the bush being pressed out, an appropriate drift used, and the bush basically forced out of the 'axle end' with a hydraulic press. This is by far the easiest way of doing this job, and I would recommend paying your local engineering works whatever modest sum they want for the use of their press, because it certainly saves a lot of blood sweat and tears. Yes, some come out fine, but if they won't, you've already got the radius arm out, and you won't be able to drive to the engineering works to ask them to do it…

Realistically the only other sensible way of removing old bushes is to use Polybush's own Bushwacka tool, which is basically a very strong threaded bar with the correct size inserts to pull the bushes in and out. (They also make a handy tool for pulling the drop-arm balljoint cup out too..)

The only real problems were the Panhard rod bushes and the bushes at the axle ends of the rear radius arms, which I suspect had never been changed, and all these had to have the rubber forced out, and the outer sleeve sawn in several places with a hacksaw in order to remove them.

Once these had been cut with a hacksaw, the tension was effectively removed from the outer sleeve, and the bushes could then be pushed out with the press.

Just a little tip: When any of the radius arms are removed, effectively the axles are free to 'fall' wherever they like. When lining the front axle up, you can judiciously use a long heavy bar against the engine mounting to lever it back into place. With the back axle, use a 4"-wide ratchet strap around the axle, attached to the rearmost chassis-body mounting bracket which will pull the axle back into place as the ratchet strap is tightened.

One of the advantages of the Polybushes is that are much easier to fit than the OEM rubber ones. Instead of them having to be pressed in, the bushes themselves can just be 'pushed' in by hand, and the inner metal sleeve is just squeezed in with a vice. A little washing-up liquid can be used to help the metal sleeve slide in nicely, if necessary.

Conclusions:

If Polybushes served no other purpose than being easier to fit than the OEM Land Rover bushes, they'd still be worth every penny, because if you've ever tried to remove stubborn OEM bushes, you'll understand how much work it can be.

It's reassuring to know that when the time comes to replace the Polybushes, they can be removed and refitted by hand, even in the garden if need be, rather than needing a hydraulic press standing by, to be on the safe side. Half of the OEM bushes on my Camel Trophy Discovery needed to be cut out, and they hadn't even been in that long; I dread to think how hard the job would have been if they had.

Not only are Polybushes dead easy to fit, they last 5(ish) times longer too, which is a tremendous bonus if you intend keeping the vehicle for any length of time: they're easier to replace, last longer, improve the vehicle's handling, and actually work out cheaper than OEM bushes in the long term.

As well as being much, much easier to fit, they improve the vehicle's handling dramatically. They 'tighten' up the vehicle's handling beautifully. The vehicle wanders a lot less, as a result of the new Panhard rod bushes, and it also rolls less into corners. Considering the serious amount of extra weight carried in unusual places on a Camel Trophy Discovery, if they improve that, I would say the improvement on a 'vanilla' Discovery would be even better.

As an example, I recently carried 6x Defender 130 rims and tyres on my roofrack, and now the Polybushes have been fitted, the vehicle was more stable on the motorway than it was before, unladen.

Polybush say their bushes 'restore that factory-fresh feel', and I have to say that's a spot-on description; the vehicle just feels tighter and more agile, with less roll and slackness. I suspect this improvement would probably be even more noticeable on a vehicle with bushes that were in worse condition than mine.

Occasionally people say that there is an increase in NVH (noise, vibration & harshness) when polyurethane bushes are fitted, but I would have to say there any increase is absolutely minimal, if at all. When travelling in a straight line, apart from less tendency to wander, there's no difference at all; the vehicle just feels a lot tighter and better behaved, with no downsides at all.

If you've got a Camel Trophy Discovery, I'd highly recommend the red-blue hybrid set that I fitted; there's absolutely no downsides to them at all, apart from the higher initial purchase price, but even that will be recouped if you own the vehicle for more than a few years. If you've got a 'vanilla' Discovery, I suspect the benefits would be even more noticeable, because of the lighter keb weight.

Polybushes are available from Polybush, or from selected distributors in the UK at around £250 for a full set, including VAT.