Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Workshop Note - Bump Stop assists

Many years ago I audited a spring manufacturer in Sheffield who were major players. They were developing valve springs for the Ford Zetec engine.

At that time, there was a huge problem with aftermarket MGB leaf springs, which just didn't last, and were rarely close on camber (with each other)from new.

I had a long chat to the technical director/engineer, who just laughed at the ridiculous situation, driven of course by owners wanting cheap replacement springs, and manufacturing going overseas..

He got out some of the technical drawings for MGB leaf springs, which they had once produced, and the specification was extensive. The bottom line is that unless the steel used is to the exact specification required, and tempered according to that specification, the spring may look like a spring, but it won't survive long.

Much later I took a pair of new MGB springs to a manufacturer in Rotherham, and had an extra leaf added, and a re-temper. It didn't even cost that much.

Even later, a trend emerged for "Parabolic" single leaf springs, but they went the way of other substandard springs and soon developed an "S" shape.

So this journey brought me to where I am now, and the modification of a new set of four leafers using Tribo tape. I won't dispose of the original six leaf springs. I will strip them down, and maybe remove a leaf, add Tribo tape and keep them as spares, just in case the four leafers don't last. The thing is, those six leafers from 2004 are still as new, but with a fairly unyielding ride. What fun it is to experiment!

Hi Lorne, great to see that you have withdrawn your condemnation of Roger's "thingies"! You can maybe see why some of us were surprised you could be so judgemental without experiencing how brilliant they are.

I recently sold my 2014 4/4 as I had become increasingly unhappy with aspects of the modern cars. I ended up buying a 1987 plus 4 and have realised how different the old cars are. The roadholding and behaviour is so much better on the 1987 car. I'm really addressing your comments about post 2004 cars....whilst the rear parcel shelf of my 87 car is narrower, it is alot longer. I wonder if , when the factory moved the panels backwards possibly without moving the spring mountings at all, maybe the panel behind the seats now sits further over the leaf spring, more towards it's centre and so more liable to contact when the spring flexes. I'm also thinking of my 1978 plus8 in which the prop would hit the tunnel often, but the springs never hit the body. Like you, I find it hard to believe that no-one can make a decent leaf spring now, there must be something else contributing. My 87 car has substantially more ground clearance and therefore a quite different relationship between the springs and the body and chasis. Also the axle is different and in a different place.
Generally, it seems to me that many of the modifications to the cars since the eighties, due to legislation etc. hvae chipped away at the original design and have not improved the car from a driving point of view at all. In fact the changes have added obstacles to the handling. My 87 car feels better through the steering wheel for instance. I really don't see that removing the damper plates improved things at all. And that's including that my older car has a steering box! Somehow the modern car seems harsh and difficult in comparison with the older one.

Just a few thoughts, nothing dogmatic.
Nick

On Peter Ballard's advice I bought and fitted 4 leaf springs from BCC to my 4 seater last year. Very impressed so far with the improved ride quality. Also centralised the axle and raised the back end so I'm rarely grinding the rear plate..

Peter gave me a whole ton of excellent advice regarding springs, re-valving the Armstrongs and making some bumpstops. Can't fault him.

The factory which make the springs for BCC and Suplex SSL are still in Rotherham as per DW's description above, they can make from scratch, re-temper & modify to order

When this Covid cr4p shoves off I'm going to try and organise a TM visit to watch some proper hot metal bashing

I remember back in my Steel career as a metallurgist we made a one-off batch of spring steel. 150t of silicon steel. Cast to ingots then rolled to billets for the customer. I can’t remember the customer though. An interesting exercise.

That is interesting what you say about the older cars Nick. It has always struck me that the rear telescopic dampers were perhaps sub optimally mounted on later cars. To my mind the mounting eye axis is not great, ie 90 degrees out. Perhaps the axis should be parallel with the axle axis rather than tangential to it. The problem I see is that owning to the different shackle heights the axle actually moves 6 degrees off the vertical rather than vertically and this to some extent must put unwanted strain on the dampers and their fixings. I don't know if this also translates to a small effect on behaviour or not?

I prefer the Rutherford damper mounting orentation.

Not to worry Nick. I am still judgmental. Essentially, these thingies are not bump stops (though they can fill that function) They are a substitute or supplementary rubber suspension. It was deemed needed, ultimately, because so many leaf springs Morgan installed were/are defective. They are an effort to compensate for a very basic, very bad component supplied to many of the cars after some date in the mid-2000s. Another expression of that the frequent failure of that component seems to be the flirtation with 5 link rear suspensions. I could not figure why anyone why trade a delicious and rare rear comportment (assuming all is as it should be) based on many centuries of usage and theory, for anything.

If something ain't broken, don't fix it! So it must be that something was broken, at a very fundamental level to have occasioned ingenuity like Roger's. It is based on the curse "ALL MORGAN DO THAT!" when in fact, the best policy is to assume only one's own does. Roger's and 5L suspensions implicitly assume that the ALL Morgan leaf springs are kaka and Morgans, as they should be, are wanting in this area. Just think of what that says about tens of thousands of owners from 1936 to 2004!! Actually, I think it really says more about owners of Morgans made after. When I ran into the failing leaf spring problem with a few MMC-supplied 4&5 leaf sets for my UK Morgan, I found away to get a set that lasted outside the MMC network. It never occurred to me to re-invent Morgan rear suspensions.

The current treatment of Morgan front ends is analogous. True, Morgan began using a too long rebound spring many years ago causing front end steering to be ..er..excessively stiff but this was vastly compounded by the current lack of regular (simple) maintenance of the area ,[/i] (has the average stomach become too big to maintain a Morgan front end?!!!).

Perhaps there is a current new fetish about making one Morgan more complex that I am missing. After 250,000 miles of mogging with only myself and my wife to care for us and the car, I can tell you that the greatest thing is Morgan adventuring and that is impossible to do in a non-simple car you can't fix roadside. Morgan simplicity and performance and ride were its stellar virtues, though yes, they are also very pretty..



I am far happier you saying that than I. Sad, isn't it? I am ideally positioned to appreciate what you are talking about. The MMC re-created my 1984 in 2002/3 using parts and ideas (some never used in other cars) from the entire history of Plus 8s. (The UK dealer network kicked in new old parts from old inventory to help with the project). So I had a bird's eye view of what happened to Plus 8s over a 36 year period. The best I can say is that Morgans are like wine..with good years and eras and ...er.... less good ones. The quality, ride, etc does not follow a linear path upwards over time. Also, after 2004 they change so often that they become progressively harder impossible to track, car to car. I abandoned that attempt for the GoMoG Manual a decade ago. We can discuss the whys of this 'til the cows come home. It is interesting.

However, every Morgan trad (bless'em) can be sorted to a great extent with a screw driver and some common sense. The first and most important thing is examining what is NOT working for you and finding out why. Obviously, over a 100+ years, it worked for someone with a Morgan..so why not yours now? I exclude new stuff like PCBs that fail while on a holiday. Nothing to be done.

Good to know you Nick. Thinking out of the box is so rare these days. One must believe the evidence of their senses, divorced from current advertising and community templates. You do that. Very refreshing.

Lorne

The virtue of the "hoop" is its strength. Rutherford made a hoop, shaped differently, that extended the distance of the lower mount and made the upper mount in a way that made the shock angle far more upright and permitted the installation of longer shocks...many more choices and better ride quality, so he said. He was never very proud of the super popular shock kit he invenedt..especially after others began copying it in cheaper metal and selling it without his input.

Did you know that the first such kit was a one-off made for TOK before its LeMans victory? Except, the shocks were canted rearwards behind the axle as it was the assumed direction of an incoming impact for Chris Lawrence and his team. Bill Beck, the Factory Developer, said THEY assumed the impacts would be coming in from the side. No one really studies these things like AFTERMARKET does.

I think you may have a point in theory...but remember that each Morgan, because of the variables on a flexing frame (even an extra 25 kilos on a driver will change suspension effect and comportment..I can tell you moving a left mounted battery on a LHD to the right is a noticeable difference. I stopped fiddling in the rear after I deeply liked the drive and my wife confirmed by snoozing on rough country roads! Also. I like a very simple car and preserving the template/datum (as George Dow calls it). So much of wonderful Morgan camaraderie is based on a commonality of mechanical problems. (GRIN!) Your system has moggers leaving that fold, albeit that is compensated for by its simplicity. Those who are beguiled by complex addons lose more than they gain by adopting them. By they way, I do not treasure old things merely because they are old. I treasure simplicity and common sense no matter where or when it comes from.

For me this problem boils down to finding a RELIABLE Morgan leaf spring maker for ALL 4-wheelers. Preferably, that would be one in the USA (lots of old springs needing replacement ) and one in the UK. Shipping costs are enormous otherwise.

Lorne

I think you are missing the point made in several posts above re the axle having been moved in the car but the wheel arch apertures remaining unchanged which creates contact points with much reduced axle deflections compared to older cars.

Another random thought about Roger's assistance units. It seems to me that if the leaf springs are soft they will move easily to the point where they encounter Roger's thingies (!). At this moment two things happen. 1. they meet the stiffer resistance but still compressing rubber. 2. The length of the leaf spring is effectively shortened causing it itself to be stiffer in response.
So that means that Roger's invention creates a perfect double response spring system. Soft over the initial movement, hardening as the load increases.
That may be why they work so incredibly well?
Nick