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

Teetering on the brink here - the car is in the garage so not a problem to make a call and add it.

Who fits Panhard rods and why?

I am looking for a quick but comfortable road car so am going for SUPLEX suspension with new rear dampers which I hope will smooth out the London potholes and speed bumps. I have ruled out anti-tramp bars for now as to track focussed.

Why would I add a Panhard rod, is it only for very fast road or track work? Will I get unpleasant feedback or chassis noise from it? This is a car that the other half will be in quite a lot so comfort is important!

Or are there no downsides to it, it just aids handling and there is no reason not to fit it?

I did a search and read the notes, a few have them fitted and like them. But are they the hardcore of Moggy drivers rather than those going for a picnic at a country house on a Sunday..? Which is me, with a little bit of the former if I am on my own

Thanks and I promise to stop making new topics

The Panhard rod made a noticeable difference to the handling of my 4/4 Sport Competition when I had it. There were no downsides. The feeling of the body moving sideways relative to the rear axle disappeared and the car felt much more "planted" on the road, even in normal road use. Just do it - you won't be disappointed.
Don.

The one great upside is that the Rod de Panhard stops the plate that the U bolts go through rubbing grooves in the vertical web of the Chassis Z section as the axle goes up and down. My 4/4 has barely 1mm clearance, the Rod de Panhard stopped the rubbing and delayed chassis repairs!
OK a sheet of stainless (?) inbetween the lower U bolt plate and the chassis would have worked too........ Regards PJB.

Like Max, I fitted one to my 4/4 Sport. It took away that sideways lurching on the rear springs on cornering. No effects on ride or road noise as far as I can tell.

I fitted one to Woodstock in the very early days of ownership and greatly improved the handling from pootling about and supermarket car parks, to speed hill climbs. It also stopped the propshaft hitting the tunnel when carrying a passenger.

Only downside is the need to look after two extra joints, but hardly an onerous or difficult task even with rose joints; a wipe over and a spray of oil suffices.

After fitting one and doing 20 miles, you'll not be asking "who needs them?" but "why didn't I fit one earlier?"

Just to drift off topic a bit, I would ask the same of the brake reaction bars, are they really only useful if doing track days, sprints etc or would you notice a difference in "normal" driving?

The only time I have noticed a problem without them is under very heavy braking on uneven/broken surfaces when I got a lot of judder as the tyres seeemed to grip then let go, I assumed this was do to the top tube flexing. Fitted 'brake braces' and not got it since. Under normal driving I doubt if one would notice any difference.
A piece of thick wall steel tube £5.00, and a couple of M8 nuts & bolts does the trick. No downside apart from extra weight.
NB watch the route of the brake flex hose relative to the new brace! PJB

PJB, Seems a cheap mod with no real downsides.

Panhard rod is great, was first thing I did, it really improves that stability of the rear end. If you are after a comfortable ride go for AVO's on the rear and leave at softest setting, talk to Peter Mulberry at Mulfab, there are 3 types of AVO's and only one is right for a Morgan, he can advise.

All this information is making me think

Thanks chaps - your advice was taken onboard and a Panhard rod is ordered

As you've all said - no downsides.

Hi there - who did you order one from?

No idea - Bill Wykeham is getting it sorted for me.

I would guess it'll come from Mulfab though..?

More than likely. They make the factory ones I believe.

Thanks both...

I have used a much simpler approach to control the sideways effect on the rear cart springs which is as effective as a panhard, yet costs next to nothing.

I simply fitted a piece of oak between the spring clamp & the chassis ( On the offside & nearside) using existing Shock absorber bracing hoop fixings, then greased the wood where the spring clamp rubs up & down as the axle moves up & down,this prevents any side movement Ive had this in place since august 2011 ( approx 10k miles) & there is no wear of the wood, there is no noise , no adverse effects & no cost.

I have posed some pics on flickr you should be able to view them at [img]http://www.flickr.com/photos/55174869@N05/[/img] sorry i don't know how to post pictures

That's very neat!

I like your work...

+1

Slight risk of the Panhard Wood Weevil.

So Morgan's do have wooden chassis afterall. All those experts who come up to my car & tell me that have been right all along

I get mine made and are fully adjustable

Has anyone developed a Watt's Linkage for the Morgan? The Holden V8 racing cars in Australia used to have a live axle with a Watt's Linkage.

Watt's a watt's linkage ??

To quote Wikipedia
Watt's linkage (also known as the parallel linkage) is a type of mechanical linkage invented by James Watt (19 January 1736 – 25 August 1819) in which the central moving point of the linkage is constrained to travel on an approximation to a straight line. It was described in Watt's patent specification of 1784 for the Watt steam engine. It is also used in automobile suspensions, allowing the axle of a vehicle to travel vertically while preventing sideways motion.

http://en.wikipedia.org/wiki/Watt's_linkage

Must be true I guess

Thanks John - I could not resist the question!

The advantage of a Watts linkage over a Panhard rod is the former keeps the axle movement in pretty much a straight line up and down, whereas a Panhard rod allows the axle to describe an arc, ie a curved path.

To my mind, the path described by the axle is only really an issue when the allowable suspension movement is great, ie an off road or rally car but you pay the penalty of carrying more weight and of increased maintenance as there are twice as many joints.

Beamish Morgan describes the A-frame alternative.

Harald

It's an expensive alternative, even if you can persuade them to make and fit one.

If you want a Watts linkage , Scimitar cars used to have this arrangement , they also used Salisbury axles with a special cast cover to accommodate the pivot point not sure if it will be straight swap for the Morgan tin diff cover tho'

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?

I just take out the parcel shelf and spray the rear springs with motorcycle chain lube. It weeps into the bits you can't see.

I don't bother to jack up the car but it does seem to work

Adrian, it helps if you remove the rear dampers, a time consuming task I know - but then when you spray the first 'coat' you can immediately bounce the rear of the car to see if there is an improvement AND bouncing helps work the spray grease between the leaves whilst the thinner in the spray grease is still thin. Hope this helps - PJB.

For the doubters about the effectiveness of two bits of wood, I have tried it and can assure you it is effective, oh and another is advantage is negligible weight gain.


If you want ensure the leading edges of your springs are well lubricated & don't want to remove the old hardened stuff every time, you can make a simple tool which comprises of a couple of sharpened axe like blades say about 20mm long 12 mm deep & 3mm thick welded either side of a smallish "G" clamp.
As the G Clamp is tightened on either side of the Leaf it will separate the leaf's enough to squirt in some engine oil or whatever.
Im not sure if this will work on a Morgan ( access) never tried it but it works on an Alvis

Thanks PJB, I jacked up rear and with axle cover removed I managed to spray from below and above and get they grease into the springs, and the mop up the excess that dripped. The next day I drove the car forgetting I had done it and noticed the improvement immediately. Still firm but more comfortable and less harsh on bumps.

+1 for denso tape had it on my old Land Rover for 20 years, the springs still look new underneath.