MJ LEE Twin-damper Mounts

The product background:

Twin-damper mounts were originally designed for comp safari racers, who race very highly modified Land Rover-based vehicles race around a course against the clock. Up to a point, comp safaris are the 4x4 motorsport equivalent of a stage on a 'car' rally.

In this kind of environment, the whole vehicle, and especially the suspension, is punished remorselessly lap after lap, and any weaknesses can become apparent very quickly indeed. It's not uncommon to see these vehicles running tremendously expensive long-travel full-on racing dampers with remote reservoirs and Rose joints, but on some tracks, where there are a lot of heavy landings, or hundreds of yards of corrugations to be travelled at high speeds, even these can fade, blow their seals, or simply break. Equally, full-race dampers aren't cheap; good ones can be several hundred pounds each, compared to only several tens of pounds each for good-quality 'standard' dampers.

In brief, there are several merits to using twin-damper mountings:

Firstly, they halve the load on any damper, by having two dampers controlling the action of the spring rather than one.

Secondly, the dampers can be removed and refitted without removing the turret. This is important in competition, because the less time is wasted during servicing, the more work can be achieved.

Twin dampers also give a margin of safety and reliability, as if one damper fails, there is still one working, rather than none.

To explain this in slightly more detail, twin damper mounts basically halve the forces acting on each damper, so each one is worked less than a single damper, making them more reliable, and making the vehicle's handling more predictable over the course of a safari; if a damper is starting to heat up due to being worked hard, it's behaviour is going to change.

As each damper is working less, the intervals between strip-downs and rebuilds can also be increased, or equally, perhaps fewer dampers are actually required. Instead of having to take perhaps 8, 12 or more dampers (fitted singly) to an event, and having to change all four between races, if twin-dampers are fitted, perhaps only 8 are taken and fitted to the vehicle, and can instead be stripped down and rebuilt after the event at the mechanic's leisure. Alternatively, perhaps lower-specification dampers can be used, reducing the costs involved.

The benefits in fitting twin dampers to a Camel Trophy Discovery (or a Defender) are similar to that of fitting an anti-roll bar, with the benefits favouring off-roading rather than on-road performance.

When vehicles are fitted with winches, bullbars and steering guards, these are all fitted well forward of the axle, so the extra weight is multiplied because of the 'leverage' applied by the distance between them and the axle. If you imagine attaching a 10-foot beam to the front of the vehicle, and the standing on it, you can appreciate that the front of the vehicle will be forced down further than if you just stood on the bonnet.

With twin dampers fitted, when the vehicle is being driven on the road, as before, each damper is being worked less because there are twice as many, which will stiffen the vehicle's handling, and when off-road, the vehicle doesn't lose any axle articulation like it would if an anti-roll bar was fitted. (As an illustration, the new Series II Discoverys actually have better axle articulation than the TD5 Defenders, because the Defenders are now fitted with anti-roll bars.)

A correctly-specified and fitted anti-roll bar will improve the vehicle's handling on-road to a greater extent than twin dampers will, but the trade-off is that it will be worse off-road, and will increase the possibility of becoming cross-axled. Also, none of the pre-93MY Discoverys have the chassis brackets for mounting anti-roll bars, so they would either have to be fabricated and welded on, although some firms do suggest fitting them with riv-nuts.

The mountings:

The two best-known firms manufacturing twin-damper mountings are M.J. Lee and QT Services, both of whom are involved in comp safaris and other 4x4 events, and although they are both involved in similar competitions, their products are surprisingly different.

After looking at both designs, I felt that Matt Lee's design was the most likely to work successfully on a Camel Trophy vehicle, as the QT Services mountings need to be bolted to the chassis at the front, and as Camel Trophy vehicles already have the winch bracket, bullbar and steering guard bolted to these points, if nothing else, the old bolts would need to be removed and replaced with still-longer versions, and all the above would probably need realigning afterwards, which can be fiddly to say the least. In QT's defence, because their mountings are bolted to the chassis, the strain on the captives which hold the turrets on will be substantially reduced. Considering that most Camel Trophy vehicles are used basically for commuting, and greenlaning and 4x4 'fun days', I doubt this extra strain will actually cause the captives to fail. If the vehicles were used for comp safaris, then it may be an issue, but in Matt Lee's instructions, it states that if the vehicle is used competitively, then the turrets should be welded on anyway.

The mountings themselves are made from two vertical loops of tubular steel, bent to form an inverted double-U-shaped 'cage' over the top of the primary damper (the one fitted in the original location inside the spring), with a secondary horizontal U-shaped loop facing towards the front of the vehicle welded to one of the primary loops. This secondary loop is also reinforced with 45deg. bracing. The mounting plate is cut from thick steel, and the whole thing is substantially sturdier than the standard Land Rover pressed-metal turret. The quality of the fabrication, welding and powder-coating is superb.The mountings arrive from M.J. Lee powder-coated, which should last well, even despite living under the wheelarches in all the filth and mud. The turrets are gloss black powdered, and the axle brackets are a very vivid red (so everyone can see you've got fancy expensive suspension components fitted!)

The instructions were clear and straightforward, and even the bolts and washers for the Panhard rod were supplied. You could buy these mountings without needing to go and buy anything else, apart from the captive-bolt plates, perhaps.

Fitting:

The fitting, it would have to be said, looks like being somewhat tricky because of the shape of the inner wing panel on a Discovery.

Looking at the advertisement, you get the impression that the new turrets just basically replace the standard Land Rover ones; on a Discovery, if you were simply replacing the Land Rover turret with an MJL /single/-damper mounting, then all should be well, but the horizontal loop for mounting the second damper fouls the inner wing on the Discovery, realistically meaning that this panel will need cutting and reshaping in order to get it in. (To be fair, even fitting an MJL single-damper mounting would improve matters, as the damper could then be removed and refitted without removing the turret, which is a little more tricky on a Camel Trophy Discovery because of the winch cabling etc.)

The matter of fitting the turrets is further complicated by the fact the the brake lines run down this panel, and then through it towards the bottom, where they attach to the flexible hoses, meaning the panel can't simply be cut up; the pipes need moving out of the way temporarily, or rerouting permanently.

At the moment, I'm in the process of cutting up the inner wings on a crashed Discovery in order to work out exactly where to make the cuts on the inner wings to clear the turrets, and how to subsequently remake the panel. The choices seem to be to either remove basically the whole inner wing and remake it accordingly to clear the turrets, or perhaps to just put a horizontal cut in the wing and judiciously bend it clear, and then weld it up afterwards.

If you have a comp safari vehicle, or perhaps even a Defender, in terms of removing the old turrets, firstly, before you do anything else, either go and buy 2 of the captive-bolt-plates that secure the turret from Land Rover. Chances are, those captives will have been subjected to years of filth and road-salt under the wheelarch, and if you haven't removed the nuts before, the studs may well snap when you start trying to undo the nuts, and if they do, you won't be able to drive the vehicle to buy new ones. New captives aren't expensive, and are well worth fitting for ease and piece of mind. While you're at it, buy some of the nyloc nuts that hold the radius arm bolts on; they shouldn't be reused, ideally, and unless you know how many times they've been removed, for the sake of a few pence, you may as well replace them.

If you do decide to replace the captives, you'll also need to beg, borrow, or hire a coil spring compressor to squeeze the springs down enough to get the captives out. Use good quality compressors, and pay attention to the instructions on how to use them. Vehicle coil springs can store a frightening amount of energy, and if the compressor slips or breaks, and your finger's in the way, you'll lose it...

To fit the lower brackets, just remove the front radius-arm-to-axle bolt completely, and slide the bracket onto the bolt, with a large washer either side of it, as per the instructions in the kit. Refit the bolt, and then lift the bracket into place up against the Panhard rod bracket. On a RHD vehicle, the left-hand side (nearside) Panhard rod bracket will have the lower end of the rod in it, so remove the bolt, offer up the bracket, and put 2 washers behind in and one in front initially to see if it lines up. Adjust the quantity of washers on both the radius arm and the Panhard rod bracket until the bracket fits squarely, with nothing under any stress. Refit the bolts and nuts, and torque them down to the figure shown in the workshop manual.

The 'opposite' side Panhard rod bracket will be empty, but the principle is the same, except you use the bolt supplied in the kit, as there isn't a bolt in that bracket.

To remove the Land Rover OEM damper-turrets and the damper itself, simply read the section in your favourite workshop manual. (Basically, remove the bottom damper-mounting-nuts, remove the outer damper bushes, noting exactly where they came from and in which order, remove the four 13mm nuts holding the damper-turret in place, and lift the turret and damper upwards. The damper can then be removed from the turret on the workbench.) It needs a bit of wiggling, but it'll come out.

The offside turret on Camel Trophy Discoverys can be a bit trickier, because the waterproof box containing the winch solenoids, and the cables, get in the way a bit.

If you've ever wondered exactly what dampers do, just give the damper-less corner of the vehicle a gentle push downwards, and watch how long it bounces up and down...

The primary damper (the one inside the spring) can be fitted before or after the MJL turret, although it is slightly easier to do it beforehand. If you're going to fit it first, make sure the inner bushes are still on the bottom of the damper, and then lower it into the lower mounting hole. Refit the outer bushes, and the loosely fit the lower damper nuts.

Make sure the upper inner bushes are in place on the damper, lower the MJL turret onto the top of the damper, refit the outer upper bushes, and loosely refit the nuts. Then just push the MJL turret down onto the studs, and start refitting the 13mm nuts, making sure it's being pulled down evenly.

When the 13mm nuts are done up, make sure all's well, and then tighten the top and bottom damper nuts to the specified torque figure.

If you'd prefer to fit the damper after the turret, which can be easier because you're not having to push the turret down against the force of the damper, then once the Land Rover OEM turret is out, simply clean up the face of the coil-spring turret, and fit the MJL turret in it's place, using copper-grease on the 13mm nuts. Make sure both inner bushes top and bottom are still fitted to the damper. The damper can then be wiggled through the side of the MJL turret until it's lined up in the lower mounting hole, and then simply pushed in until it's in place.

Refit the lower outer bushes, and loosely fit the bottom nuts.

Let the damper extend itself until the top mounting is through the upper mounting hole in the turret, refit the upper outer bushes, and loosely fit the nuts.

When the damper nuts are loosely done up, make sure all's well, and then tighten them to the specified torque figure, and that should be that.

Conclusions:

If you've got a Camel Trophy Discovery, or a winch-equipped standard Discovery without anti-roll bars, then I would say that twin dampers should make a tremendous difference to the vehicle's behaviour: dive under braking should be dramatically reduced, and there should be less body-roll into corners.

With twin-dampers, you should have the majority of the benefits of anti-roll bars, with none of the compromises when you're off-roading. There might be a slight trade-off in terms of ultimate on-road performance compared to anti-roll bars (although the vehicle will still be dramatically improved over the standard vehicle), but if you've got a Camel, or a winch-equipped Discovery, then you're obviously a pretty keen off-roader, and so the trade-off ought to be minimal.

On the downside, you'll need to adjust the inner wings, which isn't for the faint-hearted, and obviously you'll also have to buy another 2 dampers, at least initially.

Common consensus has it that fitting twin gas dampers (Old Man Emu, DeCarbon, Bilstein etc) will probably over-damp the vehicle, meaning the dampers will try to do the work of the springs, which isn't an ideal scenario at all; when these damper turrets are fitted, I'm going to try using one DeCarbon and one OEM Land Rover damper, to see if the OEM damper 'supplements' the damping of the gas DeCarbons.

The MJL twin-damper-mountings are available from MJ LEE , or from Simmonites 4x4 in the UK at around £175 for the fronts, including VAT.