Talk Morgan Forums Community The Malvern Arms Rear springs

Dave
Dan White of Suplex developed the original 4 leaf springs specifically for a Morgan Plus 8 owner who wanted more comfort because of back problems. It went on from there and became a production design at Morgan. The asymmetrical springs are a more recent development of the same design.

If you really want the latest development in comfort and handling you should consider the Suplex 5 Link rear suspension system. Yes, it is expensive, but it is well made and has been through a testing and development program of over 2 years. I can't personally comment on the feel of it on the road yet as mine will be installed next week however I am very happy with the Suplex RS front system that I already have installed.

There is a long thread on the topic here which includes comments from one of the people involved in the testing program.

Peter , with a light car and a great deal of unsprung weight in that live axle i dont expect too much in the ride comfort area , but if the springs are due for repacement then i may as well pick the best option which looks like the assimetrical springs you recommended. If i then start to experience axle tramp i can always add anti tramp bars like the ones offered by Mullberry without compromising the ride .
I shal call the factory and check if they stock a set for my car .
Dave

Dave,
The 4 leaf asymmetric springs have their mounting eye set in the current [i.e further back] position. Your +8 is a 1996, so should have Lockheed brakes [cable operated, not rod operated handbrake] and should fit safely. However the upper shock mounting on the roll hoop may now be out of alignment and therefore need spacing, either with longer bolt and sleeving at the top or by de-centring the axle, as below.
If you have a rod operated handbrake, the revised rearward axle location WILL cause this mechanism and the fuel tank to foul. If this is the case I would suggest using Mulfab axle centring blocks mounted 'back to front' with the 4 leaf springs, effectively to de-centre the axle and win space.
A 'side effect' of fitting 4 leaf springs is that your rear shock absorbers may lock out on compression. The geometry of removing leaves is that it reduces the available space, the currently available AVOs appear have a greater compressed length that some OEM shock absorbers. The factory went through a number of iterations of rear shock absorber bottom bracket; to gain more space, to make them strong enough, etc. My own solution was as recommended by Mulfab, this was to obtain longer, replacement mounting brackets manufactured by Three Elms. A check on their website will show the before and after brackets, their replacement ones are worlds away from the OEM bracket, being double skinned and having an additional pick up point as well lowering the bottom shock absorber mounting.

Wow Horror ,
There's something to think about , are you saying that the distance from the front eye on the spring to the point where the axle is mounted is different ?
Now if the lower shock mount is on the lower spring retaining plate then it would be raised by the difference between the thickness of the original spring and the thinner replacement ,perhaps an inch ? Now as i expect to raise the rear of the car by again an inch then the installed length of the shock would remain the same . So i don't anticipate any issue there but i am concerned re the length from front eye to axle .
BTW i do have cable opperated handbrakes
Dave

I have a set of Peter Mulberry's 4-leaf (non asymmetric) springs together with Panhard rod and anti-tramp bars, and we found that the standard AVO rear shocks did indeed have the wrong extended and compressed lengths.

Fortunately this wasn't a problem, Tim Ayres was able to get a set made up with the desired characteristics, and it only took a couple of weeks.

Dave,
Yes, the axle is moved back when current style springs are fitted. Mulfab quote 15mm. If you study current pictures of cars in build you will see an offset from the rear face of the shock absorber hoop to the forward most washer on the top shock absorber mount, this spacer is missing on early hoops.
As to the reduction in distance between the top and bottom shock absorber mounting points. This for two reasons, the overall depth of the leaf itself, 4 leaves compared to 6 - and - the nice new springs are a damn sight softer, so the car sits down and flattens the spring and reduces the space the shock absorber can compress in. So much so that when combined I found I didn't need lowering blocks at the rear to match shorter front springs.

I am told that the actual difference between current Morgan production 4 leaf springs (and the Suplex asymmetrical springs) and the older 5 leaf springs is actually 20mm. This is the difference between the two mounting positions available on the new Suplex 5 Link kit.

This should not be a problem for anyone with a cable handbrake but should certainly be considered by anyone who has the handbrake mechanism mounted behind the diff. Horror makes a very good point, and one that I had forgotten to mention, about the handbrake mechanism. Fortunately this is not a problem for Dave as he has the latter cable operated brake.

Regarding the fact that the car rides a little lower with the 4 leaf springs. This, according to Dan White of Suplex, is a designed feature because leaf springs work best when they are near flat when in use. In other words once the car is loaded with luggage, fuel and passengers they should be as close to flat as is possible within the constraints of available space for bump and rebound (not much on a Morgan).

The apparent softness of the 4 leaf springs by comparison the the 5 leaf springs may be more because of less stiction between the leaves than any great variation in the spring rates. If you want more information of a technical nature it is probably it is probably best to contact Dan, a very nice guy and a dedicated Morgan owner.

Was The job done ?
Peter.
Î put panhard rod yesterday
It is the good model for my car.
Thanks

Old and new +8 spring, pinned on mounting bushes

detail of distance between new and old eye

Goes to prove just how impricise and variable the manufacture of the leaf springs has been over the years.To my eye that looks like a difference of 8mm between the two. Mulfab's wheel centering blocks move the axle back 15mm, Suplex say the difference is 20mm and your measurement clearly shows somewhere about 8 or 10mm.

Joys of hand built cars