Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) 2011 4/4 - susp & driveshaft advice needed please

Good advice Paul F.

Morgan Cars Australia decided to fix the sagging springs on my new 4/4 by simply removing ONE of the lowering blocks.....

You can imagine what that did for alignment not to mention it was an illegal modification in my part of the world. The Feds got involved as the vehicle was not Australian Design Rules compliant with regard to ground clearance - I won't bore you with that story.

I do love Lornes write ups. He so very nearly listens to what you tell him.

The factory chopped and changed spiting suppliers a few times in the mid 2000’s
I did a great deal of work with Dan White (Suplex, now SSL) in working out the correct rear spring rate needed (and what is actually manufactured) including working with Reading University to design and ascertain whether it was possible to fit a composite rear spring (MMC wouldn’t detail change the chassis to allow it to fit)

Dan White in his then role as UK director of Eibach Springs and supplier to MMC visited a Chinese supplier of leaf springs and rejected an entire production run of springs for being of varying and out of specification quality.

Leaf springs are a b*ugger to design as the friction between the leaves changes depending on use and environment and hence the spring rate also changes

Polishing and deburring the individual leaves and interleaving with a slippery polymer film (as I did for the Peking Paris +4) can make a huge difference, but is hardly ideal for production

The leaf springs fitted to the 4/4 in 2011 were fitted with lowering blocks to obtain the correct ride height, whether they were too stiff, or of the wrong parabolic arc, or just way out of specification I don’t know....

The Mulfab four leaf , four seater springs are identical to the four seater factory springs,and manufactured by the same supplier ( they just happen to be in Coventry) and are probably the best solution to saggingrear springs

However in the original posters case I would be tempted to simply remove the lowering blocks ( this may need new U bolts) and see if the increase in ride height cures the issue
Certainly a cheaper option than new springs

Simon @ SiFab.co.uk

Thanks SimonH, Good background and history. Thank you for posting.


That suggestion was made with my car but it was pointed out that if the original springs were from the dud batch as were mine as well as the second set Morgan provided then you are just hiding the problem. Both cars were built at the time of the "Spring Sag Issue" so that is a distinct possibility given that other cars delivered in Australia suffered as well.

It would be interesting to measure the side to side difference in ground clearance.

New 4 seater springs have solved my problems.

Thanks everyone for your advice here, ineteresting backgrounfd there too Simon, thank you.

Had a great chat with OZ 4/4 today too, feeling much more relaxed about it and have a plan of action - involves replacing the springs of course.
Many thanks for your time and advice OZ, really appreciated that 👍🏻🍾🏁

Changing leaf springs is surely the best way. I don't know what dampers you have, if they are standard, why not replacing them with adjustable dampers in a first time?

On my 2005 PLUS 4 when I have changed the rear dampers with adjustable ones, big improvement, no bottom out after.
Testing the previous standard ones (35 000 miles) they are like a bicycle pump.

If your dampers are not good or enough efficient, it does not help. They don't have the same function as the springs, but it could improve your concern. Not difficult to change,not too expensive and in a second time changing the leaf springs?
It could be a good investment for the future even if you change the springs.

CBY is right the standard dampers are rubbish.
Changing them is easy.

Thanks John and CBY - do you have a recommendation on brand and model of damper to use ?

Having been through this whole issue I agree entirely with Simon.

Even before our car left the factory it had ground clearance problems and hit the peak of the ramp when going up into the trim shop to have a couple of last minute things fitted. On the way home, fully loaded we must have hit nearly every speed bump. The clearance under the car was less than 9cm!!!

In the end the factory replaced the springs under warranty and a set of earlier 5 leaf springs were fitted. In one way or another the handling of the car was completely stuffed up.

Finally I was an early adopter of first Peter Ballard's SSL front suspension and then the rear 5 link suspension. Both of these I have tuned to my taste and I have even fitted higher rate rear springs. I have also fitted 195/65 R15 tyres to improve the ground clearance.

In the case of the 4/4 I fail to see that the rear end of a 4/4 would have a much different weight than that of the Plus 4. Take away the spare tyre (if a Sport) and factor in the lighter weight of the engine and I doubt that you would reduce the load by more than 10 or 15 kilos per spring. Travelling with or without passenger, and or luggage, and or a full tank of fuel would make more difference!

The springs are certainly a bit flat, ideally they should be like that only when the car is loaded. If you don't want to spend the money on upgrading the suspension, obviously my preferred choice would be the 5 link rear suspension, I would definitely remove the blocks (new U bolts) and, at the same time, fit a set of decent adjustable dampers.

While you are at it I would consider fitting a panhard rod too. Some would say it is not justified on a 4/4 but it will tighten up the rear end and improve the handling at a very small expense.

Try this & choose one.
http://www.gomog.com/allmorgan/shocks.html

I have AVOs fitted.

I have the SSL suspension at the front which was delivered with adjustable SPAX dampers. So in a second time I installed adjustable Spax dampers (by Librands) at the rear which are fine.

https://www.librands.co.uk/products-view-215.html

Morgan propose also SPAX dampers (the same? not sure):
https://www.morgan-motor.co.uk/mmc/shop/...-front-604.html

In the community AVO seems to be the most popular.