Talk Morgan Forums Morgan Sports Cars Morgan Plus Four, Supersport & Plus Six (CX & CXV Generation Vehicles) Ground clearance on the Plus Four

Well we finally got Florence back only to have our plans for a few trips out to be curtailed by the wipers packing up as per my earlier thread. Our trip to the Lakes was out of the question so we returned home from Manchester on Sunday. We were two up with a suitcase on the luggage rack that probably weighed about 25kg and the luggage space behind the seats was full of bits and bobs.

We were lucky with the weather and set off from Greenfield heading for Holmfirth as part of a circuitous trip home.The A635 across the moors is a perfect Morganeering route but sadly identified another issue with the car. Namely the lack of ground clearance at the rear. Cruising along at 55 to 60 in the sunshine was extremely pleasant until we came across some mild undulations when the exhaust grounded and the mem sahib screamed which I found most disconcerting. The road surface was good and as I said the undulations were only mild certainly not conditions where you would expect to ground the car. It has grounded before but that has been either on rough roads or an unseen pothole. Our Roadster would not have grounded under these conditions even with twice as much luggage on the rack and in the car.

Having read the Plus Six thread regarding ground clearance I have measured my car (with half a tank of petrol and 28 psi tyre pressure) as per the Plus Six thread from the ground to the inside edge of the wheel arches and the results are as follows.

Rear O/S 627 Front O/S 634
Rear N/S 634. Front N/S 636

Having looked under the car it is evident that the rear ends of the four exhausts are grounding and the fact that the off side of the car is lower is borne out by the deeper scrapes in the two off side pipes. I'm off to Krazy Horse in the morning to have the wipers fixed and will get them to look at it then. In the meantime I would be interested to hear other peoples' experiences with this issue.

The rear can be adjusted as I’ve had mine done but I still need to have it raised up a little more as the French speed bumps in some small villages are killers.

Many thanks for your response p8mog. I will raise that with Krazy Horse tomorrow.

Yes those 30 km / h bumps are right swines in France.

Sorry John, no experience of the grounding but would be interested in what KH say…
HB

didnt knew that .Do you have adjustable dampers ?

No I don’t have adjustable dampers, the factory did the adjustment.

Adjusting the dampers only affect the softness or hardness of the actual ride. To be able to adjust the ride height you need to have coil over damper suspension units with adjustable spring platforms. Myself and other New Zealand Plus 6 owners have purchased such units from SSL for our cars.

While the ground to outer wheel arch measurement is an easy way to check your suspension height, what you should do is to measure the ground to chassis height at each of the jacking points. The are the flat surface with a hole in them and adjacent to the attachment point of the lower wishbone suspension arm. You should have front left and right 135mm and rear 155mm plus or minus 5%.

What have you got?

Kerry

JJR a visit to Dan or Peter at SSL may help. Their dual rate spring solutions will reduce suspension travel as full bump is approached. Works beautifully on my 5 link Roadster two up even with full tank and touring luggage. All I add is a couple of clicks on the dampers, never had to touch the spring pre-load.

I have similar measurements as yours at the wheel arches, JJR. I have made up a simple Go No-Go device for measuring the ground clearance under the silencer, a block of 100x50mm wood with a 6mm hole drilled in it to take a 60x6mm gutter bolt. The bolt can be pushed up or down to just slide under the low point of the car. A long handled brush is a handy tool for manoeuvring the gauge to the right spot. My measurement is 80mm of clearance, 28psi in tyres and unloaded. I would be happier with 105mm that some have mentioned in other posts.