LOWERING BLOCKS FOR LEAF SPRINGS?
by Lorne Goldman, the good people at General Spring, JRA, Eaton et mon ami Hubert Clot

Placing blocks under or over rear leaf springs is a cheap, quick, down and dirty way to raise or lower a vehicle, but they are far from the best way and exact a price to be paid in comfort and handling. They are understandable in amateur racing, where track surfaces permit, but most often at a prejudice to the pleasant use of the same car for any other activity. Facts and physics show that the use of such blocks causes axle wind-up and the need for panhard rods to stop the springs from moving sideways as the blocks also create a smaller flat surface and encourage twisting from side to side. 

Any "leafsprung" vehicle is at its most stable when the spring seat at the axle is closest to an imaginary line drawn between the front and rear eye of the given spring. As the distance between the spring seat and this line increases, so does axle wind-up. Axle wind-up aka "tramp" is a phenomenon in which the torque transmitted to the wheels by the axle which causes the live axle to turn in its own centerline. 

The more the axle rotates because of axle wind up, the less stable the vehicle will be.

For these reasons (and one more if you read a bit farther!), the use of blocks to change the ride height of any vehicle is not recommended.

In the distant past, GM, Ford and Chrysler and other manufacturers tried blocks on the rear of some of their trucks. Pay close attention to the next one you see traveling down the road. I have recently. (Older model trucks are easier to find in South America! :D) Follow one for a while and you will notice how the axle attempts to twist. This twisting happens on all vehicles as they accelerate and brake. However, the twisting is much more severe on lowering block-equipped vehicles.

These blocks are no longer used by these or any other manufacturer I am aware of. They were an attempt to save money rather than fitting different springs to vehicles used for carrying different loads rather than fitting springs that suited the vehicle, the desired ride height and the load it is to be used for. 

Most unfortunately, blocks also lead to unacceptable shortcuts in a vehicle as light and sensitive as a Morgan. Morgans are SO basic that any component or lack of maintenance that is not perfectly suited to it quickly manifests itself.

The saddest example of this in the Morgan world, outside the racing community where such usage is often acceptable, is the Morgan 4/4 Sport.This is/was aesthetically lovely entry level model, introduced a few years ago with a strictly limited option range..with set colors and interior. It was stripped of bumpers, overriders, spare tyre, etc and achieves a low weight reminiscent of earlier eras, from 17% to 20% lighter than the other Classics, being Plus 4 or the Roadster, with most of the weight saving at the rear.

Some years ago (circa 2010), when the complaints started, I discussed this with Simon Hall, who was then working for Peter Mulberry. Simon told me it was "he who created the 4/4 Sport's configuration when he was working at Richard Thorne Ltd.", a Morgan agent specializing in racing Morgans. Simon should perhaps be forgiven for the following because of this background and his youth at the time and he was working for a race preparer which is a very different venue, with a very different set of needs and priorities than road going cars require.

Apples and organges He assured me that the Factory adopted his design wholesale. Unfortunately, this meant that Morgan took leaf springs specifically designed for notably heavier models and fit them to the much lighter 4/4 Sport, rather than fitting springs made for the Sport. Of course, with less weight to support, these standard springs (I am a fan of them) pushed the 4/4 rear way up in the air! To correct this, Simon and the Factory used lowering blocks, something found often on UK amateur racing Morgans. They can lower a rear end for a neglible small cash outlay. So this corrected the height, but not the fact that these springs were made for much heavier fare. The result is a harsh ride that discourages adroit cornering, which was the 4/4 forte and delight before this modification, and the inexplicable frame switch in 2004 from the 4/4 frame to the heavier frame used for Plus 8s, Plus 4s and Roadsters. The very hard ride is noticed by owners who have owned other Morgans previously, but fortunately not new owners who have never known anything better. Sadly, since Simon abruptly left Peter Mulberry, his story on this changed. This is no solace to the owners with these 4/4s and made this 4/4 version a liability. Morgan tried to counteract this by returning a more classic configuration (thus affecting their hopes for a more reasonably priced entry model). Young Simon can be a very competent mechanic and I wish him well.  However, in this instance, and for the sake of 4/4 history, he should try to be more candid and helpful for the sake of these owners.

WATCHPOINT: Beware the GoMoG LAW OF RACING MODS FOR ROAD-GOING CARS.  The simple truth is that the goals and environment  of racing produce modifications unsuitable and unhappy for road-going cars. The priority of a racing team is to win at all costs. This is done within a venue where the car's support infrastructure is mere meters away on surfaces that make suspensions redundant. If something goes wrong, the car is back in the paddock in minutes or on a trailer with its team having beer and party sandwiches. I have pitcrewed for racing Morgans in many places on three continents and it is GREAT fun and very exciting. More moggers should attend! Choose your favorite before the race!
Road-going moggers (almost all of us) have different priorities in vastly different venue (s) than racers. We have NO support structure roadside. We have NO need for rollbars (ugly thingies) and lowered suspensions. I have never heard of a road-going Morgan flipping, though racers are required by racing rules to have them and I have seen a racer, poorly handling his Morgan, flip. We need as much ground clearance as possible. We need a suspension that is capable of being comfortable in all sorts of roads, understanding that the smallest country roads rather than super highways, are the most fun for our cars.  We cannot tune our engines until they are at their maximum performance, as that jeopardizes reliability which is ALL-IMPORTANT for a road-goer. We must use other methods to more power, but unlike racers, they are open to us as we are not tied to race classification rules. On the other hand, we must follow laws on speed, emissions, safety...that racers can ignore. The list is endless. We should not be copying racers without a good deal of wisdom added. Racers show us what can happen if....cautionary lessons.  When I see Morgan non-racers with rollbars, lowered suspensions, racing cams, side-pipes and the lot, I feel bad for their cars and prejudiced usage. GoMoG (with 260,000 mogging miles and counting!) There are many other paths "us roadies" can use to achieve a more confortable, more powerful Morgan in every area. Road-goers have their own set of great modifications specific to THEIR usage. Of course, many non-racers want to look like racers which is a different thing alltogether.   

Morgan stopped offering options of different leaf springs on new cars when they began using the newer 4-leafs. So I have no out-of-the-box perfect solution to this problem on these 4/4s saving having made-to-measure springs fitted which is exactly what should have been done at the outset. This is fairly easy to have done and common in the US, Canada and Australia where roadside companies are constantly re-fitting long-haul trucks and automotive modification options are more common at the retail level. Being me, I will keep musing and if I can find a less invasive solution that can suit, I will add to this article. Sadly, it is much easier to make a suspension stiff than compliant.
 
WATCHPOINT: These blocks should not be confused with the centering blocks sold by Mulfab. Their purpose is to merely to center the rear wheels in their wheel wells for aesthetic reasons adopted by the Morgan company a few years ago. In the newer Morgan design, the wheels were centered by shifting the axle centering bolt rearward. The Centering block design has a negligible effect on either comfort or comportment. The lowering blocks at issue have an entirely different effect, as described here.

Another solution should be to add weight to the rear, by way of adding the missing spare tyre and then removing the lowering block. The spare tyre is very important to the dynamics of Morgan handling as its effect is multiplied by its placement..as it is cantilevered far behind the axle. Those of us who overweigh the rear with luggage can attest to the change in comportment and handling. You can test this easily before any commitment simply by weighting the very rear with 25+ kilos in a sand bag (understanding that the rear of the car will drop with the weight..to no ill effect for the brief time of the test..just choose a non-potholed stretch. I am always told the result is an marked improvement, largely correcting the Hall/Morgan effect. However, it is always sad to add weight to a sports car. The best solution is new springs made for specifically for this model. This should transform these cars. Sadly, Morgan has recently moved from British suppliers to India-sourced products of an inferior quality. They too often sag or break.

GoMoG Law of Replacement: Why Replace An Original Component That Has Proven Itself to Fail, Over and Over Again? The long list of such decisions, since the beginning of the Steve Morris era, has incrementally degraded the traditional Morgan to the point where its demise was sadly necessary. Prior to his regime, a new Morgan could be relied on to be trouble free for years and warranty claims were ALWAYS generously dealt with. I like Steve and wish him well. But production shortcuts, cheaper components and ridding the work force of expertise is not a recipe for long term profits no matter what they are making on Pickersleigh Road this week. Additionally, constant draconian untested changes, effectively Peter Principles the entire workforce and suppliers. 

MMC Lowering Blocks Redux 2020
 (coming)

SAGGING LEAF SPRINGS & BUMP STOPS
by GoMoG and Hagerty 2020

Over the last 2 months, I have received a growing number of inquires about rear suspension "bump stops". It is not a part that I often received inquiries about. It didn't make much sense until I investigated.

The proper way to deal with sagging leaf springs is to replace them. But in a nutshell, owners are currently being advised by a British forum, not noted for mechanical expertise, that the best way to handle increasing bottoming out at the rear is to install adjustable bump stopss  This sadly leaves any understanding of autombile dynamics behind in the dust. It is akin to addressing a sniffling nose by beheading the sufferer.  :(  However, the subject forum's has become infamous among the cogniescenti for such stuff. and that always leads to less-than-the-best "solutions". Answers are posted by non-professionals without thinking them out or doing any even elementary research. And the few professionals on the forum keep silent, not wanting to offend their market (I guess!).

The cause of increasing and ever more severe bottoming out at the rear is simply that the leaf springs have sagged.  A bump stop is NOT a  "fix.  The simple fact is that leafs springs are carefully arc'ed to create a specific ride height that places the sprung weight (almost the entire vehicle)  at an ideal point between full compression and full decompression. As the leaf springs age, they sag but that usually takes a LONG time. That can take about 10 years, depending on the quality of the springs. On my 2002/3 Morgan Plus 8, (with the older 5 leaf springs and 100,000 wonderful kms) there is no need for change as yet. It was the same with my 1984. I place my Morgan on axle and crossframe stands during any period of dormancy.

Trying to compensate the aging of components with add-ons that deal with only with the syptoms of aging make the aging effect worse rather than remedying it.  By adjusting bumps stops to sagging springs, one has more bottoming out, not less. They merely change the harsh clang of bottoming out to a more frequent duller thuds by limiting the suspension travel EVEN more with each adjustment! So using adjustable bump stops locks oneself and the car into ever less fun. When a component is worn, REPLACE IT, preferably with something better. And if you discover that a component Morgan put in your car is substandard, get something better..or do you need repeated proof of the same thingie failure to take action? ;) 

THERE IS SOME REALITY TO THIS SAGGING. The Factory has had sad experiences (and passed this on to buyers) finding reliable leaf springs since some point after 2002. As noted, my "old" supplier 2002 leaf springs (5 leafs) have lasted 18 years with negligible sagging (1 cm) (and great flexibility)  just like those on my first Morgan. Yet just 2 years later, I went through 3 sets of new MMC-sourced 5 leafs in less than 18 months (under 5,000 miles) on the Morgan (also a Plus 8) we kept in the UK.  This sagging only stopped when I switched to the newer 4 leafs from Peter Mulberry (the same as those used by the MMC after they stopped sourcing from their decades old orginal leaf spring maker. I heard that this supplier and others were also cancelled by Morgan after repeated sagging.  THE FIX IS BETTER QUALITY LEAF SPRINGS..NOT SCOTCH TAPE SOLUTIONS. Focus on causes not symptoms. 

Actually, the spring rate of leaf springs do not change when they sag, but bottoming out becomes a constant pathetic problem as the springs and shocks and everything at the rear is no longer placed in the right height dynamic which makes everything dynamically askew to some extent. Sagged springs "bottom out" MORE frequently and adjustable bumps stops makes this even more frequent.

The ONLY smart solution is new reliable leaf springs arc'ed properly and the Factory has not been able to reliably do so and now they have no reason to so since the early 2000s.

So far, leaf spring offerings from the UK aftermarket can be bizarre. For example, one seller is flogging "antitramp leaf springs" which are stiffened to the point where the car's ride, its comfort and it handling is prejudiced. We all went through this with a Libra Motive product made the ride painful unbearable about 25 years ago. .

Proper bumps stops soften the very properly rare impact of bottoming out. They are merely pieces of rubber and/or internal stops built into in shock/dampers like Rutherford AVOs. They absorb the impact of suspensions in extremis. They cure nothing.

What is the solution? That is complex question now as Morgan has stopped using leaf springs in current production and what they were selling seemed to have been inconsistent for a number of years (the last 18?) with the dealers I have spoken with. There as a time where/when leaf springs could be re-arched but that practice is rare now in most countries out side of those with LONG tricking distances. (Trucks still commonly use lead springs.) It can be done at home using one of two methods.

1. cold re-arching: This requires special equipment. The leaves are separately laid across a pair of arbors and a hydraulic press presses down on the leaf, between the blocks, applying pressure fully across the leaf, at a 90-degree angle to its length. A trained technician starts at one end of the leaf and presses down on numerous points while moving across the length of the leaf. The technician will space out the pressure points about the distance between the arbors with each press of the machine. A rhythm must be developed to do this just right. Pressure is applied from one end to the other along the entire length.

The ends of the leaves move about an inch with each press. Each leaf is re-arched separately. The technician avoids putting too much pressure at one point and breaking a leaf. At the end, each leaf will have the same arch. They will then be re-assembled in their original position and orientation with new center bolts and tie clamps. The cost is not terrible..about $200 for a pair. However, it only restores ride height for a short period as the leafs will "remember" their sag stat and return to it. 

2. hot re-arching: The steel used to make springs has “memory” that makes it want to return to its shape. The heat-treating process erases the spring’s memory of its sagging by annealing each leaf in the spring pack individually, reshaping it and re-heat treating it. After disassembling the pack, each leaf is heated to at least 1,650 degrees Fahrenheit to clear its memory. 

A pattern is used to re-shape the hot spring leaf to its correct arch. It is then quenched in special oil to cool it rapidly. It is now shaped correctly, but the heating and quick-cooling process creates hardness and brittleness that has to be removed. The leaf is re-heated to at least 950 degrees for a set time to draw out some of the hardness. It is cooled slowly and then shot-peened to relieve stress.  Few companies have the equipment and know how required to heat-treat a spring. This makes the process much more costly than cold setting. A pair of leaf springs was recently re-arched by the cold setting process at a cost of $100. It would cost a minimum of $450 to have the same job done by the heat-treating method! (ugh)

The best solution would be to have a set of new springs, designed for YOUR trad and not another different model with different weight and weight disribution. However, this is not something we can look to the Factory for any longer. They have not been able to resolve these issues for almost two decades and there is less chance of this now than at any time since Morgans began. It is a given in the trucking industry that leaf springs will last an average of 100,000 miles (160,000 kms). This has also been the experience with properly maintained Morgans prior to the last 18 years. 

WATCHPOINT: I maintain my leaf springs with a spray of a silicone penetrating oil and by keeping the car on stands when it is not being used for more than a few days. The stands prevent the tyres from being boxed (becoming mis-shaped from too long in the same position with the car's weight on them) and also takes all pressure and wear off the suspension. Yes, suspensions deteriorate faster on the gorund without usage than they do when being used!

Happily, I know of at least one Morgan professional who is investigating lead spring sources and new manufacture. Since the demise of the trad Morgans, the Community MUST find and adjust to other part sources and treasure the lore collected ASAP.  WATCH THIS SPACE!

As well, I am searching North American suppliers. That continent's trucking industry and distances make leaf spring expertise better and more easily found for custom applications.
I hope I have not insulted or discouraged anyone. I have a great admiration for amateur Morgan fiddlers/gadgeteers. They have provided to only advances in trad technology in the last two decades, and now that Morgan Classic models have been cancelled, these are the people we need and that the old collegiate format used to provide. However, I no longer know of a Morgan forum that fills this need and that should be rectified,