Most Morgan owners know about the "Sliding Pillar" designed by HFS Morgan back in the early 1900s and that it is still used to day. This is just one of the items that makes this car near and dear to us.
There are 3 unique items to the Morgan suspension: the bushings, the damper blades and the one-shot oiler. Replacing the bushings will require the rebuilding of the front end. (See the article by John T. Blair - Rebuilding the Front End - here on the Morgan Web page.) The damper blades can replaced with out totally disassembling the front suspension and the oiler doesn't really contribute to our problems.
Bob Nogueira's explanation of how the front end design can cause the front wheels to wobble and how the damper blades help correct it is one of the best I've seen.
"The Damper Blades were not fitted to three wheelers I believe because the large wheels, light weight, and low speeds did not result in front wheel shimmy.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 approx 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
Another item unique to the Morgan is the front suspension oiler system. The manuals suggest that the front suspension be given a shot of oil from the one-shot pedal, immediately at start up every 100 mi. There is a lot of controversy over this. Most feel that all this does is to wash the grease out of the bushings, thereby causing them to wear prematurely, and throw oil over the underside of the car. Many owners have replaced the oil lines in the top of the kingpin with an addition grease fitting and/or replaced the standared kingpins with upgraded hard chrome versions with larger grease gallerys.
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 Kingpins
by Lorne GoldmanHardchrome kingpins have a long but quiet history in the community. They were installed by enthusisasts as far back as the 1960s. (N.B. The Factory mistakenly tried show-chroming pins in the 50's but the soft surafce didn't last more than a few weeks of driving).
Invariably, the hardchromes lengthened the lifetime of the front end by many multiples. Two after market 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.
One can now purchase hardchrome or stainless steel kingpins for the same prices as mild steel pins or make some out of C1045 bar stock.
They 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 unrusted surface. The Factory moved to stainless steel pins in 2004.
Hardchromed or stainless kingpins can be fitted to ALL trad Morgans.