Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Panhard Rods - who needs them?

Beamish Morgan (was John MacDonald's) describe an "A-frame" arrangement which stabilises the axle but is simpler and lighter than either a Panhard Rod or anti-tramp bars. It's on their website but unfortunately no picture.

That is neat. I wonder if it isn't marked (looking at the photo)is it actually doing any work? But I can certainly see the theory and wonder if some form of plastic/nylon would be a suitable alternative.

Interesting point......exactly how hard do you have to "push it" before you get this sideways movement that the Panhard Rod prevents or limits?

I am in the process of installing a telescopic conversion kit to my 4 seater and noticed as I removed the Armstrong lever arms that the spring shackle bolts had scored the mounting plates.

Neil.

I think a plastic solution would work well; Nylon is pretty tough, perhaps even HMWPE.Vesconite also if it is available in thick sheet form.When I rebuild the suspension I shall be looking at a tribological grade of PEEK for the bushes.

Extra friction would just add to the damping action in sharp cornering. Early Citroen 2CVs had adjustable friction dampers although not made of wood. So it is proven technology
Harald

Surely the rear leaf springs work on the principle of friction between the leaves - old technology but still works well if set up correct and with some lubrication

Coulomb friction is one thing sliding past another, like leaves of a leaf spring, so is related to displacement and so there is an initial 'stiction' before the leaves move and the spring compresses/extends. This gives a harsh ride and prevents the tyres following the road surface, that is why no road vehicles use friction damping any more.
Hydraulic damping is related to velocity so at low velocity as the car goes over dips and hollows or cornering enables the tyre to follow the road; also dampers (such as the Bilsteins) can be tuned to give the right combination of damping force in bump and rebound and at low velocity (eg entering a corner) and high velocity (bumps) to give good ride and handling.
So hydraulics have it, get rid of friction between the spring leaves with spray grease. Regards PJB

PJB Point taken, and knowing Rosie the +8 I doubt if her springs have have seen grease. Just one thing can get to the 50% of the springs under the car can the rest be accessed from the the sides of the fuel tank via the hole where the spare wheel sits?

Adrian, the spray should work its way through between the leaves even if you can spray just one side. With no dampers connected, the rear of the car should bounce a few times after say kneeling on the rack and releasing, then set the bump damping.
Worth a try - PJB.
PS Although no road vehicles still use friction damping in their suspension, there is at least one recent/current military vehicle still in use with friction damping - a tracked vehicle made in USA. It uses the 'Hartford' type dampers but as the 'scissors' are worked in bump direction they tighten up to increase the damping in bump, hence there is no bump stop as such - the friction gets so great as the pade are squeezed the bump travel is eventually halted - one has to then hope that the suspension spring is compressed enough at full bump to release and return. Good idea, another piece of useless info, one day maybe.....

PJB, thanks I'll buy a tin of spray grease and jack up onto stands and spray away. Do I need to disconnect shock absorbers as you imply? I presume when you say rack you mean bounce rear or drive over bumpy road?