As the spindle moves up the kingpin over a bump, the spring will have a twisting motion, this is relayed to the spindle and results in a slight turning of the wheel. If this occurs at a certain speed. It sets up a harmonic bounce which becomes a violent shimmy. This usually occurs at between 55 and 65 mph. The damper blade is bolted to a bronze plate fitted between the spring and spindle and, via the blade, is held to the chassis. Thus the spring can rub on the bronze plate and move but the plate is held still and none of the springs motion is transferred to the spindle. Since the spindle moves up and down the length of the blade can not be fixed. The blade is held to the chassis by being sandwiched between two flat bars so that the blade can move in and out. At each end of the approximately 1" by 4" bars are shims which are the same thickness and material as the blade. These are positioned and pressed up to the blade's side as guides and the bolts hold them tight so they can not move fore or aft thusly preventing unwanted (side to side) lateral movement of the blades.
Both the shims and blade wear since the blade rubs on the shim every time the wheel moves up or down. As the blades and shims become worn, their edges lose the height necessary to act as a stop and they pinch rather than guide (stopping movement entirely). To test for wear, grab the blade and push forward and back. If a click or movement can be heard or felt the shims need to be pushed tight against the blades. There should be free movement in and out, from the center line of the car, but no movement otherwise. I check mine every time I grease the car, and adjust the slack out."
by Bob Noguiera and Lorne Goldman
This is one of the more intriguing (and sadder) stories of Morgan design. It remained unique only to Morgan as part of the front suspension from the 1950s to 2002 when it was finally removed. The manuals of the day suggested that the front suspension be given a regular shot of oil from the one-shot pedal immediately at start up every 100 mi. In fact, it did and can not lubricate the suspension as its kingpin exit hole does not reach the reservoir section within the stub axle. Others suggest that it is there to lubricate the damper blade plate, but the MMC was quite clear in their 1920s articles that this plate was a FRICTION damper. Oil would prejudice that. In any event, all stub axles grease that plate automatically from a drilled passage coming up from below.
The only thing that testing and experience has proven is that use of the one shot oiler;
1. can dangerously foul the brakes
2. cover that area of the car with dirty oil
3. offer the opportunity for a broken one shot oiler valve and/or lines and void the car in minutes of motor oil..to disastrous effect.
4. Dirty the floor around it.
Replacement of the old oiler system with a grease zirk make no sense. The older passages are not made for the passage of grease and the grease will NOT go far enough down to reach anything of significance. The exit hole exits too high to server the stub axle grease reservoir
Why is the one-shot oiler there? It was placed at the insistence of Peter Morgan (NOT HFS!) who had seen something similar with Bentley (different design). Though there was advice against, one does not argue with the boss, especially a well-loved one. The oiler was removed as soon as internal diplomacy allowed in 2002. Few, if any experts or dealers had suggested its use for decades before.
It was removed completely. However, in 2007 the MMC replaced the damper plate and blades with steering races (bearings) copied from the systems of eMog and that of Peter Mulberry. However, their stub axle design proved inadequately be replenished bearing with grease. To assist in this task, they once again drilled passages down their kingpins to feed the bearing housing, a wider one that would specifically feed their bearing system with a large grease nipple atop the kingpin.The aftermarket systems work well without this passage. Just grease the lower grease nipple normally and wait for the grease to appear at the edge of the bearing cup.
See Front
Suspension Lubrication
The only remaining part of the front suspension that can contribute to the vibrations is the steering box and the tie rods.
Borrowing a section from Fred Sisson's book (Notes from a Morgan Garage), he discusses a problem with the tie rods:
"I found a source of play on my +4 steering. It is a simple adjustment to eliminate it. The Pitman arm (on the steering gear box) transfers it's motion to the tie rod (the rod between the front wheels transverse rod) via the drag link. The ball end on the drag link fits into a clamp-on fitting on the tie rod.The Morgan has had 3 or 4 different steering arrangements. The first 4/4s were similar to that on the Trikes. They simply had a reduction gear mounted on the steering column. This was quickly change and a Burman worm and nut box was installed. This was used up until the later 1980s when the steering box was changed to a Gemmer box. I'm of the understanding that the factory now uses a rack and pinion system.I noticed that the first motion of the transfer rod would twist the tie rod about 1/8 of a turn before it actually moved the tie rod. The ball tie rod ends allow this rod to twist that much.
By loosening the clamp and rotating it on the tie rod slightly, the twisting motion was eliminated, thus tightening the steering action some.
I've checked a friend's +4 and found the same problem. You might want to check your car too. Just have a friend move the steering wheel while you watch the action of the tie rod. With a little experimenting you will find a position for the clamp that will not twist the tie rod.
Fred Sisson 1992"
Note: This old Burman box is no longer available and has almost no adjustments. As it wears, it will have to be rebuilt. I do not know of any sources for parts nor have I tried to find any. It also has one very serious draw back. It does not collapse. It has the old type single shaft steering column which can impale the driver in a front end collision.
The Burman box has an adjustment for loading the worm. Also check that the bolts on the top of the steering box have not vibrated loose. To check the worm loading, jack up the car and disconnect the Pittman arm (the big heavy steel arm coming from the bottom of the box) from the drag link (cross bar that connects to the tie rod). Carefully turn the steering wheel from lock to lock. There should be just a slight (ever so slight - about 12 in. pounds) increase in the force required to move the steering wheel through center. If not, loosen the locking nut on the screw adjuster located on the top of the steering box. Turn the adjusting screw slightly, tighten the locking nut and re-test. Once there is some resistance felt, no further adjustment is required.
I currently have no information on the Gemmer box other than what is in Fred's book and no information on the rack and pinion system. From what I've been told by some Morgan owners is that they are replacing the old Burman steering box with the newer Gemmer box. This will require some modifications to the steering column which is beyond the scope of this article. I've been told the Gemmer conversion will cost about $1,000). The other possibility is to convert to the rack and pinion system. Again, I have not done this and have no idea what it entails.
Mating the New Bushings to the Kingpins; REAMING OR HONING?
Some comment should be made about fitting new bushings to the kingpin. Once the old bushings have been removed and the new ones put in, they will have to be mated (aligning the bushes to each other and the kingpin and also machining the interior diameter of the bushes to allow for the right clearance for the kingpin as well). This will require either that you purchase some special tools (a reamer) or find a machine shop that will do the work. I had mine done at a machine shop for about $20 per axle.
There are two methods of obtaining this fit. One is to have the reamed, the other is to have them honed. The consensus of opinion is that the honing is preferred as a better and a computer precise fit can be attained. As well, honing allows for improved lubrication of the bushes on the same principle that encourages the honing of engine cylinder walls. Knowledgeable owners have the kingpins hardchromed to reduce the friction further.
Hard Chromed versus Stainless Kingpins
by Lorne Goldman
| Negligent or sporadic care | Proper Care | |
| MILD STEEL (MMC) | 3000 to 10,000 miles | 25,000 to 30,000 miles |
| STAINLESS STEEL (ORIGINAL MMC) | 10000 to 15,000 miles | 25,000 to 30,000 miles |
| HARDCHROME | 25,000 to 30,000 miles | 100,000 miles to indefinite |
For years, it was thought that road grit caused the premature
wear..almost always in the lower bush. The theory was that water and the
grit formed an abrasive paste that entered the area between the kingpin
and bushes and destroyed one or both. This may well be a contributing factor,
but there has never been any 
empirical
proof. In 2003, with the advent of Devol bushes, the causes for bush wear
became crystal clear. The lower part of the mild steel kingpins quickly
rusts at the bottom, where water accumulates in idle periods. The rusted
exterior surface of the kingpin then acts as a rasp, grinding away at the
bush. Stop the kingpin from rusting and the lifetime of the bush, of whatever
materiel, is multiplied enormously. That is why the popularity of hard
chromed kingpins has soared in the last few years, spread by eMog testing
and widespread experience.
Hardchromed kingpins have a long, long history in the community. They were installed by enthusiasts as far back as the 1950s. A few years ago, I spent a lovely afternoon in Birmingham with an 85 year old Morgan enthusiast and retired machinist. He had a Morgan he bought from Peter in 1958. After examining the front end on purchase, he made himself some hardchrome kingpins from centerless ground (to make the surface perfect) 1 inch bar stock. He slipped them in and never needed to redo his front end in his whole tenure with the ca and he sold it..in 1991 with 95,000 miles.
Hard chrome, also known as industrial chrome or engineered chrome, is used to reduce friction, add wear resistance and increase corrosion resistance. Unlike decorative or Show chrome ot is very hard, measuring between 66 to 70 HRC. Hard chroming also tends to be thicker than the decorative treatment, typically ranging from 0.075 to 0.25 millimeter (0.0030 to 0.0098 in), but can range from 0.005 to 0.01 mil (0.00013 to 0.00025 mm). Like all metals uses in precision hydraulic applications, hard chromium plating is subject to different types of quality requirements depending on the application, for instance, the plating on hydraulic piston rods are tested for corrosion resistance with a salt spray test. As well, the metal plated varies according to the task you wish to put it to. Steel offers an immense range of possibilities. Hard Chromes have hundreds of years of history and tested experience. If you go to any hydraulic application, (such as a earth moving machinery), you will see that the actuating levers are hard chromed. The immense feedback level and choices make it an ideal kingpin. The eMog group spread their usage and they have been used for decades. I have had three Morgans, with an aggregate of 225,000 miles on them (and counting!) and used the same HC kingpins on them throughout. In a nutshell, they eliminate the need to ever do a front end job again.
Sadly, the Factory mistakenly tried
chroming pins in the 50's but simply plated them with Show chrome. Show
chrome is very soft and if the pins are not centerless ground, chroming
actually makes the surface anomalies worse. The soft surface didn't last
more than a couple of weeks of driving. The chroming idea was shelved,
but even worse, it was from-then-on thought that chroming, all types of
chroming, would not work.
Invariably,
the hardchromes lengthened the lifetime of the front end by many multiples.
Two aftermarket sources sprung up early on, one being Greg Solow of the
Santa Cruz, CA Engine Room who hardchromes Morgan kingpins (thickening
them by approximately .012") and the other being Machiel Kalf from the
Netherlands who uses pre-made 25mm hardchrome rod. As both are not exactly
1", the diameter of a Morgan kingpin, both must be installed WITH the bushes
to ream/hone them to a proper fit. The advantage of 1 inch hardchromed
bar stock is that the kingpins can be installed at any time, simply replacing
the ones that are there without redoing the bushes etc. This will extend
the remaining lifetime of the existing front end, without undo effort.
One can now purchase hardchrome or stainless steel kingpins for the same price as mild steel pins (see Heart of England Morgans) or make some out of C1045 or C4140 bar stock.
The reason hardchromes work is that the stock mild steel kingpins rust quickly at the bottom, especially if the car is not used daily. The rusted surface acts like a rasp and eats away at any bushing materiel, whether bronze or (much faster) plastic. The hardchromes keep a slick, effectively self-lubricating, rustless surface. The unpolished stainless pins do not.
However, because of the experience with soft chrome 50 years earlier, (see above) the Factory moved to stainless steel pins in 2004. This is a non-typical use of stainless bars and, unlike the hardchrome bars, they have no history in this type of usage. To date (2008), there are many verified reported cases of premature KINGPIN wear with the Factory stainless kingpins, indicating they may have chosen too poor a grade of metal. The curious thing is that this wear occurs even with the plastic Devol bushes when the bushes show no wear!! It is hoped that the MMC will switch to hardchromes or upgrade the stainless bar stock they are buying. N.B. Heart of England Morgans uses a high quality stainless bar stock to make kingpins. There have been no adverse reports on these.
Hardchromed or stainless kingpins can be fitted to ALL
trad Morgans.
| N.B. Extensive experience with the hardchromes has shown that the life of the front end can be extended significantly regardless of what type of bush materiel is used or whether if has annular grooves, lips to prevent grit entry, gaiters, garlic or ritual chanting. |
The DEVOL MORGANS (2001-2006)
by Lorne Goldman (4 updates since 2001)
At the end of 2001, after a transition period of a few variations on the theme, the Works removed the one-shot oiler system first installed in the early 1950s and began using new kingpin bushes rather than the traditional phosphor bronze bushes used for almost a century. Many have refer to them as plastic" or "neoprene" or "nylon" but, in fact, they are not. They are Factory machined from a polyethylene plastic called Devlon S made in Scotland by a company called Devol. They have been brought in with the hope of extending bushing life AND to make the task of bush installation easy and home friendly.
These bushes are a "resultant fit" meaning that the bushes
will automatically have the correct ID once pressed into the stub axles
without the need for reaming or honing. To makes this possible, the Factory
is reaming the stub axle tube to a standard ID where as before this was
not done and the ID varied from stub axle to stub axle as their tubes distort
when mated to the cast axle. We shall call these the Devol axles. The Works
reports that their test car reached and passed 50,000 miles without discernible
bush wear. The earlier bronze could be expected to last 10,000 to 25,000
miles depending on the quality of maintenance and kingpin type.
| N.B. December 2003 There has been
much discussion back and forth as to whether these new bushes can be retro-fitted
to older Morgans. There is much confusion on this point. The MMC Development
Design Chief, Bill Beck, who was responsible for this advance states that
the new bushes should fit the older stub axles if their tubes have been
reamed correctly. (a one time job). Alternatively, the bushes themselves
can be reamed as one would bronze. HOWEVER, these bushes have a tiny ridge
on the ends. This ridge acts as a barrier to grit, and draws grease into
the area between it and the grease reservoir in the tube (the space between
the bushes and the kingpins). When reamed, this useful ridge is removed.
Nonetheless, I recommend the second method. We have not been able to determine the exact ID the Factory uses to ream the sub axle tubes. We have found that the Devol bushes vary in ID and the Factory has encountered some problems finding the happiest measurement here. They originally called for an ID of 1.24. Then they reported 1.2340 inches. (The bushes have an OD of 1.2440 +or-.0007 in.) September 2004) The Factory has restated that the axle tube should be reamed to 1.236" instead of 1.24". I would advise those interested to contact the Factory directly and copy the webmaster here with the answer. They have also advised that the older stub axle should NOT be re-reamed and instead, new stub axles should be purchased from them. There has been no explanation offered as to why this expensive solution is necessary. . |
 |
In early 2004, the Company moved from mild steel to stainless steel kingpins to prevent premature bush wear. Owners' cars, infrequently used, had a different experience from the well-used Factory Devol test car. Constant usage prevented the kingpins from rusting. Infrequent usage had the mild steel kingpin rusting, creating a rough surface which ground quickly through the Devol (as they would do with bronze..but slower.) Though the community had been using high quality hardchrome kingpins for years with great success, the Factory opted for stainless steel. For the first few years, their stainless was not of a high quality and wore faster than the Devol bushes.
More importantly, the Factory had an inconsistent experience with the Devol bushes in the UK. The bushes would swell..seizing the front end. Sometimes the kingpins would seize even before installation, as they waited in the stub axles over a weekend on the MMC parts trolley. The reports of this are from the UK..or where there is an extremely damp climate. Elsewhere the bushes performed superbly and mileages of over 100,000 are heard of when they are combined with hardchromes. The ease of installation is a pleasure taking only minutes to swap bushes.
Devols were used for 5 years or approximately 2400 Morgans,
or more than 1/2 the trads made in the first decade of the millennium.
Because of their larger tube ID they must continue to use Devol or use
oversize bronze bushes or another material machined for their axles. Oversize
bushes can be made at a local machine shop or purchased from Mulfab.
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