At the beginning of the Roadster Series II production (early 2008), the MMC made some modifications to the rear suspension. They attempted to address an axle wind-up issue that was causing the prop-shaft to impact the car in its most extreme expression. Their original solution was to fit a single Mulberry anti-tramp bar on the right hand side of the car. These anti-tramp bars were already being used in paired sets on racing Roadsters.
Traditionally, anti-tramp bars are always fitted on both sides of a car. But it was felt that a single bar would do the trick, cost less and the space on the right is partially obstructed by the battery and its fittings. The first cars with the Mulberry bars did well. Mulberry anti-tramp bars are designed for Morgans. They are additionally unique as the end at the axle is fitted with a compliant bush, press fit into the bar and through which a graded metal attachment bolt is placed. This compliancy allows the suspension to operate fully and freely, unlike many other anti-tramp solutions that inhibit the up and down movement of the suspension.
After the first few cars so fitted, the MMC decided to copy the Mulberry design in hope of saving costs. In doing so, however, they used different fittings and changed the all-important bush to something less compliant. Anti-tramp bars on these Roadsters have a tendency to shear their bolts at the axle saddle plate and bend or break their fitting bolts at their front. The improper but most common solution is to greatly reinforce the ends of the bars.
The MMC now makes the assembly with a more compliant bush and higher graded fittings than these first copies. These are a better idea for someone with this problem. The ideal fix would be to fit two quality anti-tramp bars, one per side. There are some doubts as to the long-term affect of a single anti-tramp bar on what is a performance sports car.
SUSPENSION NOTE (EARLY 2009 TRADS)
Sometime in 2008, the MMC realized that their new 4 leaf rear springs were losing their ride height, allowing the rear ends to prematurely sag to an unacceptable degree. There seems to have been an attempt to address this first with a higher arc specification but ultimately this did not provide the desired result. At some point, the company turned to a new, higher quality spring supplier with an excellent reputation. (And the cost of Morgan leaf springs since doubled.) Apparently, on fitting the first batch of these springs, it was immediately apparent that the arc specification given the supplier was now too high. So as to use these springs, the company fitted "lowering" plates between the leaf springs and the saddle plate. These are used by racers to give a car a racing profile (see racing Roadsters). In this case, they lower the ride to a more normal height.
However, in fitting these plates it is necessary to use longer u-bolts. Morgan rear u-bolt length is very important. If they are too long, they will bend and crack the thin horizontal flange at the ladder frame of the chassis. If the thin flange is broken, a crack in the perpendicular "strength) section of the frame soon follows. A SPECIAL NOTE must be attended to by these owners. The newest leaf springs have the correct arc and ride height WITHOUT this plate. When leaf spring replacement becomes necessary, the plate should be discarded and NEW shorter u-bolts used rather than the originals with these "transition" cars.
It is very easy to damage the Roadster sumps and much more through a DDE (Deadly Domino Effect). The Roadster clearance at the sump is only 3.35" on the right hand side and the sumps are made of cast aluminum. Cast aluminum sumps can crack like egg-shells. The Plus 8s had the same clearance and were frequently bottomed at the sumps as well. However, they were made of steel (the Company did not long switch to aluminum sumps as Land Rover did). Steel dents rather than cracks. It was/is a simple matter to remove them and bang them out.
So far, we have seen damage ranging from a cracked sump and a slow leak (which must be caught before severe internal engine damage occurs from oil starvation) all the way through a crack sufficiently large to instantly void the engine of oil and a domino impact that damages the gearbox, prop shaft and differential. There is no steel sump available at the time of this writing. So the best fix is that of Peter Mulberry at Mulfab. Mulberry increases the clearance at the right side by cutting down the sump. The cost is very reasonable, and there is no waiting time as Peter inventories pre-made replacements. Your old sump, in damaged or undamaged condition will need to be traded.
WATCHPOINT: Another of the more dangerous aspects of this issue
is some of the solutions recommended publicly! Invariably, these aggravate
the problem by spreading the impact area and making other
areas vulnerable to other types of damage that can be even more costly.
The worst of these (though there are many) I have seen thus far is that favored
by the Factory. They sell a "sump guard" which consists
of a very thick aluminum plate which straddles the bottom
front of the engine compartment and is attached to the car
frame at it weakest area, the thin
Morgan frame flange rather than attached at the thick
vertical section of the frame.
Front Belt & Pulley
The Roadsters use a different belt and pulley than its Ford Escape brethren.
Replacement parts are:
Pulley: Gates GNAT38008
Belt: Gates K060747