|1. Adjusting the Racks (Jack Knight and Quaife)||8. General||15. Morgan Rack Types, Servicing & Rebuilding|
|2. Bolts Through the Securing Blocks||9. History||16. Safety|
|3. Bump Steer||10. Jack Knight and Quaife (Comparing them)||17. Sequence of Failure|
|4. Center Gaiter||11. Jack Knight Switching Sides (RHD to LHD or RHD to LHD)||18. Steering Play|
|5. Changing the Centre Gaiter||12. Jack Knight Gaiter/Spacer Watchpoint||19. Stover Nuts|
|6. Center Plate to Rack||13. Lubricants||20. Turns-Lock-to-Lock|
|7. Center Plate WATCHPOINT!!! (Jack Knight and Quaife)||14. Mark Your Center Plate Bolts||21. Wheel Alignment|
Every vehicle has the same three systems that are life sensitive. These are tyres, the brakes and the steering. There can be no compromises with ANY of them. Happily, Morgan classics, (at least they were ended) are wondrously simple areas and the task to keep these areas safe is not difficult or cumbersome. Morgans get silly (and have owners react the same way) when elementary maintenance is not done. AND I cannot over-emphasize the need for vigilance or the dangers of getting the wrong advice (I have seen some horrid examples of the latter in the last decade!) If you have any doubts whatsoever, consult an experienced Morgan dealer. Happily, the key watchpoints are SO simple that common sense should warn you away from any advice you cannot immediately judge as correct at a glance, whether you are mechanically enabled or not.
In 1983, the Morgan Motor Company approached Jack Knight Ltd., a noted British aftermarket steering specialist, to design a rack and pinion steering system for the Plus 8, the heaviest of the model line-up and accordingly the most in need of a steering improvement. The resultant rack was a great step forward and was first offered in 1984 as an optional extra at £250. It became standard on all Plus 8s by 1986, unless a customer was crazy enough to ask for the older system. By 1991, it became a free option for Plus 4s and by the mid-1990s it was standard on all Morgans.
Though the design falls far short of an ideal in areas, it is a vast improvement on previous Morgan steering systems and has three great virtues; it is simple, it is solid, (save for one BIG watchpoint) and it fits on the Morgan front end. There is little that go wrong with it outside of the most basic human errors in fitting and checking it. On very rare occasion it can require adjustment, which is dealt with by David Poole in his great eMog posting, and after much mileage the rack channel and spacers may require redressing, and easy job for any machine shop. I have had a full refurbishing done in the UK for 75£s;.
The Morgan Motor Company had the stock rack's turns-to-lock changed a number of times during its history.
In 2007, the original Jack Knight company fell into bankruptcy and the MMC asked Quaife Engineering to supply the rack. For all intents and purposes, the Quaife Morgan racks are the same and can be retrofitted to Jack Knight cars. The Quaife racks can be distinguished only by their different centre gaiters, a big improvement over the Jack Knight gaiter. However, Jack Knight has been reborn under the management of its former employees and an upgraded gaiter, as good as the Quaife gaiter, can be had from them if you can get them to call back.
The old style JK gaiter is flimsy and expensive. Once they are torn (a MOT issue), the wisest course is to replace them with the new JK gaiter which is as good as the Quaife. (The Quaife gaiter will not fit a Jack Knight rack.) Quaife parts can only be ordered through the MMC, Jack Knight parts can be ordered from Jack Knight directly.
WATCHPOINT Tierods-to-Center-Plate Any time the tie rods are removed from the steering rack center plate, the steering alignment should be verified. This is made more important if the plate itself is removed and even doubled again if both clamps holding the rack to the crossframe are removed, (Though this is not strictly necessary to change the gaiter, many take both clamps off to remove the whole assembly.) All or most of this must be done simply to change the center gaiter. The play at each junction is sufficient to through your steering out of alignment. Trust ME on this and not your local non-Morgan mechanic. Many owners have found the steering canting off one way or another after a gaiter change.
The Morgan steering
racks are produced by;
|YEARS||1983 to 2007||2007
|TYPE||Jack Knight Engineering (UK)||Quaife Engineering (UK)
and sell Morgan racks direct, multiple options for turns-to-lock
sell Morgan rack direct
Changing the Jack Knight Center Gaiter (in 11 easy steps)
by Lorne Goldman
If you can, the gaiter is best changed with the rack in situ annd wheels on the ground. This may sound nutty, but if the rack is removed, it requires so many items to be uninstalled that a full alignment and steering wheel adjustment will be compulsory. This method will minimize the wheel alignment issues when you re-assemble. If you raise the car, then try to brace the wheels so that their relationship with the rack does not change during the process. Secondly, the gaiter CAN be changed with the rack in situ, no need to remove the whole thing unless you really want to. With a RHD you can slip it over the rack from the right hand side (as you are looking at the rack from the front of the car) and the from the other side with a LHD.
For those who wish to remove the rack, this can be done by removing the steering column at the rack rear and then removing the two block brankets holding the rack to the crossframe.
Open the lock tabs on the steering center plate, and unbolt the tie-rods
from the center plate (you will need a spanner to hold the nuts from the
2. Let the tierods fall to the floor and
do NOT move them
3. Open the second set of lock tabs
and unbolt the center plate from the rack.
I: The center-plate-to-rack bolts go through two spacers that slide
in the rack. They are not visible as the gaiters hide them. They create
a snug fit in the channel, reduce the amount of horizontal play, which
in turn, steadies the entire steering, (ANY BIT OF MOVEMENT HERE WILL BE
MULTIPLIED BY THE LENGTH OF THE STEERING COLUMN BEFORE IT REACHES THE STEERING
WHEEL). More on this latter.
II: These rack
spacers are designed to serve another purpose. They protect the gaiter
at its weakest point. If you look closely, (when you can examine the spacers)
you will notice thatt they have a small raised circlet in their metal on
the side that faces the bolt entry. This raised area goes into the two
gaiter bolt holes and prevents the bolts from crushing the gaiter and splitting
it..as the split will grow over time. If you are not
aware of this, the overwhelming possibility is that you split the gaiter
at these points and yet pat yourself in the head for a "job well done". Owners
do it, dealers do it, and it is very sad event at 60
quid a pop.
4. Now you remove the the bolts from the right side aluminum block holding the rack to the crossframe, split it into its two pieces with a light hammer tap if necessary. You can cut (knife or scissors) the old gaiter from the rack or slide it off the right side you opened up. Watch for the spacers to fall out.
2. Let the tierods fall to the floor and do NOT move them
3. Open the second set of lock tabs
and unbolt the center plate from the rack.
5. Now, test something. Can you squeeze the oily spacers through the bolt holes in the gaiter? You should be able to and I want you to be confident of that. Next slide the new gaiter back onto the rack, like you were putting nylons on your favorite lady (or man). Be careful not to snag it but it will adapt and stretch. You want its front (the center section with the two holes) to be facing forward and you want the two spacers to be in the correct position in the channel and facing forward. Fiddling will be involved..a Morgan tradition!
6. Now fiddle in the plate-to-rack bolts. You must align the bolts, the lock tabs, the gaiter bolt holes, the spacers and threaded holes in the rack pinion..a screw drivers and you no-oily fingers can be used. Get each one threaded loosely before you tighten anything. Please don''t forget anything or their order. You do NOT want to get me upset.
7. Once you tightened the bolts, lock the tabs. Only one bit need be touching each bolts.
8. Re-install the aluminum block on the right attaching the rack to the crossframe.
9. Forget the silly metal bands they used to clamp the gaiter, use the right-sized tie wrap and trim off the ends.
10. Then put on the tie-rods, this might require you to move the center plate along the rack. It is better to move the rack than the rods. Now close their lack tabs. Now get a bit of oil paint and make reference lines from a corner of each of the four bolts. In the future, these lines will allow you to see if any of these all important bolts have shifted at a quick glance.
The trick with the end cones is that people slide them on too far. First
deep turn and they pierce the cone with the rack without knowing it. The
rack does not require much lubrication. Almost anything will do, hypoy
oil (like you use in the axle) or chain saw oil or use the silly GoMoG
. Jack the car front on one side so it is atilt. Remove the cone. Fill
it up and fit it back on. Tie-wrap it. As you have taken the whole
center gaiter off, do it on the other side as well.
Otherwise, topping up one side is sufficent for maintenance purposes.
|WATCHPOINT III: Yes. You're right. The JK gaiter is a fright. It is a flimsy affair made by laminating (coating) silicone on a form. It is nowhere near the quality of similar gaiters and its price is a function of insane greed. ;) Jack Knight no longer supplies them.. I have heard they are now made for Morgan directly by the old JK supplier. There are those looking into a higher quality gaiter, easily sourced and reasonably priced. Perhaps that will shame the company into being kinder. However, for those of us in the UK, it is also a cause of a MOT failure. The examiners are not happy with lubricant leaks next to disc brakes. So, if you have one, do not demonstrate your one-shot oiler to them either!!!|
Morgan rack and pinion steering systems should have NO play at the steering wheel. None. There are a number of causes for play, but the most dangerous ones relate to the fitting of the rack and its tie-rods. Be aware that the length of the steering column will exaggerate any rack anomaly at the steering wheel. making the steering wheel your best early warning system. As soon as play is noticed, three areas MUST be checked before driving further.
1. the two bolts holding the centre plate to the steering rack itself.
2. the two bolts holding the tie-rods (those rods which connect the steering rack to the front stub axles and therefore the wheels) to the steering rack centre plate.
3. the four bolts (2 each side) running through the two blocks that hold the rack to the car frame.
(Consult the diagrams here).
Between 1-3 the rack is held to the car and the wheels to the rack. If they are compromised, so is your steering and your safety. At one time or another, I have seen each of these areas with loose bolts. Care can prevent this. Many times a visual test will locate the problem.especially if one removes the centre gaiter. To test, have someone at the steering wheel and have them turn the wheel while you look at the three areas, #2 will be difficult as the bolts are obscured by the #1 bolts. Do it with the front tyres on the ground and then again with them off. The rack should NOT move on the frame and the only movement of the rods should be from side to side. However..read here. Beware, those who trust today's Morgan English forums.
|WATCHPOINT V- CENTRE PLATE
These two bolts go through a lock tab, the centre plate, often a small washer and then through the important rack spacers (that keep the assembly guided within the parameters of the channel in the rack) and then thread into the pinion. Obviously, if these bolts come loose, the rack is no longer fully secures the centre plate and therefore the tierods. Effectively, the steering wheel is losing its connection with the front wheels. There are supposed to be secured by the lock tab..but this can be left off by forgetfulness, or the tabs can be forgotten (not closed), or have a insufficient contact with the bolts.)
It is hard to perfectly ascertain the state as the tierods cover these bolts. The centre plate tierod bolts, must be removed and the tierods moved away top allow these inner bolts to be examined. Once this is done, pull back the tabs and try to tighten the two bolts. Once tightened, carefully bend back the tabs.
|WATCHPOINT VI Use a white paint marker to draw a reference line from a point on each bolt to places on the plate of your choosing. This reference line will make future examinations easy as you will know in an instant if the bolt has moved if the line on the bolt and the plate are no longer aligned.|
|WATCHPOINT VII Wheel Alignment. If you remove the bolts entirely, you will have to reposition them through the gaiter and then the spacers (by fiddling with the spacers) and then find the correct holes in the pinion. This will almost certainly change the alignment. Have it checked.|
|WATCHPOINT VIII With the older style Jack Knight gaiters (approximately 8000 Morgans from 1984 to 2007), close examination will show that the spacer has a round raised area or that there is a small washer between the centre plate and the gaiter. This was done to match the holes in the gaiter for the bolts. Without the raised area or CORRECT sized washer, the plate will clamp the silicone gaiter and the gaiter will split. If you replace your spacers.|
WATCHPOINT VI- TIERODS TO CENTRE PLATE If you have properly dealt with the Centre Plate to Rack bolts, you have removed the tierods from the centre plate. Simply reassemble these, tighten and lock them with the tabs. Use the paint mark system on these bolts as well.
Simple. There are two sets of 2 half blocks that secure the rack to two L brackets on the car's crossframe. (See the diagram above indicating "rack holder" & cross frame".) Each half block has a half round centre that together match the rack and two high grade long bolts going though the two halves into the L brackets. When assembled the blocks clamp the rack onto the brackets and the frame. If the bolts loosen, the rack loosens and moves askew with steering and road anomalies. If the bolts fall out...Check whether they are tight. In the normal course, these bolts should not loosen as they are held with nylocs. However, negligence is always possible and the re-use of nylocs leads to their losing their ability to lock. One can use new nylocs, or a bit of loctite blue or ultimately, stover nuts instead of nylocs. If there is concern, use the same white line reference discussed above.
The approved lubricant (which was used in manufacture) is BP Energrease
FG 00-EP since it is a compatible with the application and gaiter material. By 2013 it was no longer available.
Here are alternatives.
Mobil Mobilux 2
SKF Alfalub LGMT
Shell Alvania R2 or G2
Esso Beacon 2
is for very anal sorts. I use any appropriate lube I have around. In my
case, in the Quebec mountains, it is chainsaw oil.
The rack is produced by Jack Knight Engineering (UK) (http://www.jackknight.co.uk/).
The following procedure should be used to adjust the steering rack. There is no specified torque setting for the adjustment locknut and the manufacturers specify that it should be tightened “sufficiently to lock the adjuster in place”.
1. Thoroughly clean the area around the adjustment assembly.
2. Remove the locknut, and remove and discard the lock washer.
3. If the rack has a significant mileage, unscrew the adjuster and remove it, together with the nylon follower and spring.
4. Check that the nylon follower is free to move within the bore of the adjuster, and that it is not damaged or worn. If it is, replace it.
5. Replace the nylon follower in the groove at the rear of the rack, followed by the spring and adjuster.
6. Gently screw in the adjuster until it bottoms as it makes contact with the rack, and then unscrew it ¼ turn.
7. Place a new lock washer over the adjuster, with the internal tongue engaged in the rebate on the side of the adjuster, and the concave side down.
8. Hold the lock washer and do up the locknut finger tight. Make sure that the adjuster does not move.
9. Bend the outer tab of the lock washer that is aligned with the gap at the front surface of the rack towards the rack housing, so that it that locks the adjuster to the rack body.
10. Tighten the locknut sufficiently to lock the adjuster in place, and bend one of the tabs on the lock washer away from the rack housing and over a flat on the nut.
An Addendum by Bill Button (Jack Knight and Quaife)
A friend drove my +8 Bitsa with Jack Knight Steering, declaring it had "Too much slop - Fix It". I had noticed some slop but thought it was just normal wear.
I removed the Rack from My +8 and looked at it on the bench. The pinion was sloppy. Seems that under the adjustment screw is a spring that pushes on a piece of plastic that holds the pinion so it meshes precisely with the rack.. Webmaster (see above). I removed adjustment nut and spring. It took a bit of effort but then removed the piece of plastic. But when I tried to re-insert the plastic I could not fit it.
I took the R&P to a mster machinis,t who is another +8 owner, for his advice. The plastic is a made of Nylatron that had swelled. Bob filed it carefully and re-inserted it and refitted the spring and adjustment nut.
Problem solved. Th Nylatron follower was not free to put pressure on the pinion and keep it fully meshed. Thus the slop.
|The approved lubricant (which
is used in manufacture) is BP Energrease FG 00-EP since it is a compatible
with the application and gaiter material. The specifications for
the grease are defined below.
BP Energrease FG 00-EP - Description
Energrease FG 00-EP is a mineral oil based, polymer-thickened, stable, semi-fluid gear grease. It contains an anti-oxidant additive and also a sulphur-phosphorous type EP (extreme pressure) additive. It has excellent shear stability, load-carrying ability and the coating characteristics that eliminate the risk of dry start-up.
This grease has been satisfactorily used by many industries overseas and in South Africa in enclosed spur, bevel, helical and worm gearboxes. The operating temperature range is -10°C to 100°C.
- Overcomes leakage of lubricant.
|N.B. Adjustment of the rack & pinion is a rare procedure. Most racks are well set-up at the outset and will stay that way for many years. Check other area for vibration first and the bolts holding the rack and those to the center affixing plate.|
|WATCHPOINT: On more used R&P Morgans, there
will be wear in the centre of the rack channel which will increase over time. My Jack Knight produced a steering wheel vibration and an up-and-down movement after
37,000kms (23,000 miles) and its seems Quaifes are exhibitting the same
issue. If the play is not attended to or the waer accelerates with the
movement that the owners are tolerating. In a bit, the feedback gets
worse and the rack is unrepairable. This was mentioned on a
mechanically-challenged UK forum but those who noticed it did not
investigate or even remove the gairter hiding the problem area. That
has many owners buy a new rack for
astronomical prices. (Morgan, though they abandonned this steering system (Jack KNight & Quaife) in 2019, the MMC still
has an exclusive with Quaife that prevents Quaife from selling to us
and many Quaife fitted cars are have wearing r&ps by now.
That keeps Morgans profit intact. R&P systems, generic or
otherwise, normally cost 20% of what MMC charge. The far more expensive
new cars (the Plus Four and Six, use these!
However, this wear can be dealt with for very little and a 30 minute wait (my outlay was a 6 pack of beer) if you have a decent machine shop nearby. I merely told him to widen the channel a bit to even it out again and create spacers with a larger outer diameter to fit as snuggly as the original spacer. That eliminated the up and down movement and the vibration. It saves an owner many hundreds, and after, all this is going to be happening again. The current MMC has boasted that the new Morgans contain only 1.6% of the components used in the cars up to 2020. Considering the MMC quickly abandons support of non-current production within a VERY short time..since the advent of the first Aero. it is prudent to either stockpile parts you will need in the furture while you can, OR learn how to repair your Morgan.
Comparing the Jack Knight & Quaife Steering Racks
by Lorne Goldman 2014
In 1983, Maurice Owen, the Morgan design chief, approached Jack Knight, a small lot UK designer of automobile parts, to design a rack & pinion steering system for the Morgan Motor Company. The first was fit, as an option, in 1983. Some 24 years later in 2007, Jack Knight ran into business problems suspended affairs for a time. Morgan approached Quaife Ltd, used for some Three Wheeler parts, to provide a replacement. The newer Quaife unit can be swapped in, without undue fiddling, to replace a Jack Knight. And the reverse will be true as well. In recent years, Jack Knight returned to business under some former employees and has become reliable supplier. That gives owners two options for their Morgan R&P replacement or special needs.
Being interchangeable, it is an excellent time for a review and comparison to help owners choose if a need presents itself.
Firstly, both racks are very simple and solidly made. I have never heard of a Jack Knight (JK) or a Quaife (Q) failure and if someone out there has..please write me. Ergo, there is no known difference in reliability. Amongst other JKs, I have my original 1984 in spares. At 100,000 miles (with my first Morgan) I did have to straighten the pinion passage and make two new spacers to match the widened passage but other than that, it served me without a problem for over 150,000 miles. However, Qs have presented no issues either in the seven years (at the time of this writing) they have been around. I know only of one failure and it was attached to a bent crossframe.
Of course, there is a lot of lore available for the JK and none for the Q as yet. The Q is a factory part and the Morgan world is therefore not informed of much from them these days. However, the similarities between the two units are such that a Quaife should not be a problem for a skilled amateur or machinist to deal with..and that is unlikely to be necessary.
Quaife Ltd will not supply the the rack to anyone other than Morgan. However, Jack Knight has lost its Morgan trade and like many of former Morgan suppliers in that position, they now supply the community direct. Though the quality of the two racks is comparable, JK units can be had at a fraction of the Quaife cost, and if JK has its act together when you call, you will receive it in much less time. (They now have a well laid out web site with online buying.
Quaife comes in one version..3 turns to lock. A Jack Knight R&P can be had in many versions to better suit each driver, 2.3, 2.7, 3.0 or 3.5. And for the many Superform wing cars where the front wheels rub and blister the paint, Jack Knight can customize a rack to prevent the wheels from doing so.
A JK can also be easily converted from RHD to LHD or vice versa. We are told that, so far, the Quaife cannot be converted. That doubles the potential market for a JK over a Quaife. N.B. Morgan's new dealership contract prevents dealers from selling any other rack than a Quaife. July 2020. I have the necessary information now to write and article on how to do the swap. Watch this space.
One advantage of the Quaife over the JK is the gaiter. Morgan
used a flimsy silcone gaiter for the JK for many years. They can split
if you stare angrily at them! (wry smile) Quaife's come with a large metal
center plate and gaiters that are tougher. However, Jack Knight designed
a similar gaiter to that of Quaife for their units. I suggest you buy it for your
JK, (if you can find and convince JK to produce one for you.
R&P Watchpoint (1984 - present) Updated January 5, 2018
from Lorne Goldman on Morgan Addicts
THE 2 PART PROBLEM
Please read other R&P articles
PART 1 The most crucial parts in a car are NOT the most expensive ones. Those can only hurt your pocket book. The crucial parts are the ones that most effect the safety of the occupants. Normally, they are found in the following assemblies, tyres, brakes and steering. These are the systems that preserve your control of your car and therefore your life.
Of these, of all of these, it would be difficult to argue that there is any as critical as the cheap little plate at the center of the Morgan Rack & Pinion steering.
Examine the Jack Knight R&P steering system to the right. The front wheel assemblies (tyres, wheels, brakes, bearings, stub axles, tie rods (#2 shaded red) are all bolted (#3) by a single plate (#4 shaded brown) to the steering rack (# 1 shaded blue) , column and the steering wheel. On the Jack Knight cars (1984-2007) it is part # MSR0287 and they call it the "steering rack mounting bracket". On the Quaife R&P (2007 to present) it is part # H-2M1-05 which is identical, so the problem seems to have been inherited from one steering system to another, unchanged in 35 years and counting. Sad stuff, but there you have it. Here are diagrams for the Quaife.
A quick examination of the diagram shows that this little bent plate (an in-house part) is the heart of the system's security and integrity. A. If even one of the inner plate bolts break, the plate will only be held to the rack by a single remaining bolt and the steering will be prejudiced. B. If one of the outer bolts holding the tie rod ends, one wheel will not longer be attached to the steering system. C. Happily the newer bolts are graded and held with with lock tabs and nylocs. However, the plate itself has been known to sheer along the fold lines without any prior indication. The result will most likely be horrific as one or both front wheels will detach from the steering system and splay outward. It happened to me at the end of one of the finest Morgan days I ever had! A fantastic 780 mile drive and just as I was entering my garage! I finished the trip with my wife and daughter at each of the front wheels steering them by hand into my workshop. I do not recall any extraordinary impact on that trip but I did notice the steering had become sloppy in the last 30 miles (by that time the plate was likely held together by bolt pressure only. However, it was night time by then and I was close to home. That was a stupid mistake..only covered by insanely good luck! And I do NOT like relying on luck.
REDUX I have been told today that my dear, dear friend Button has mused publicly that something has to be amiss in this watchpoint. Namely that my photos are suspect as he has never experienced this phenomena with his r&p. Button has offered this sort of thing before with other of GoMoG watchpoints that have saved people's lives. He does not do this with ANY malice and I only wish dear Button was right herel! The fact is that I do not recall any event on that trip which was unuusal to my 250,000 miles of mogging on two continents (Europe and America). Of course, I had a road clunk or two over the 1800 miles of back roads on that trip but nothing out of the ordinary, and the state of my suspension is legendary...(though achievable by anyone with a standard Morgan who wishes to follow this manual.) In any event, this plate should never fail NO MATTER WHAT the road anomaly. Of course, I have run across this mishap with others since..and, as well, it must be pointed out that dealers are always reluctant in this new era to get in trouble with the Factory by going on the record. I cannot count the times over the last 25 years, the more concientious Agents have enlisted me to speak for them. Many of these warnings have now been incorporated into Morgan lore and the production line.
This is time for remembering one of the most important GoMoG Laws.
|THE GOMOG LAW OF WARNINGS: There are warnings you can doubt and ignore because when they occur they can only cause annoyance. Then there are warnings, if ignored, that can cause dire tragedy with one incident. If there is no downside, always believe and act upon a warning that causes you no effort to respect. After all, what is the downside? If I am, for some bizarre reason, lying to my brethren or in error, then you are in no danger by following such simple advice, and, if I am not lying or in error, then your life will be saved without you knowing it! :)|
With the help of metal and mechanical experts, I found out the cause. These plates likely break because they are improperly cold-bent and subsequently become vulnerable at the bend. When steel is cold bent, its yield stress increases and its ductility decreases. Ductility is a metal's ability to deform under tensile stress. Residual stresses, enbrittlement, spring-back, reduction in toughness and curl are also common problems of cold-bending metal. Cold bending can cause strain-aging. Dynamic strain aging occurs during bending. But whether hot or cold bent at Morgan, it sheared. And this is not something that has to be brought my attention twice. There are parts that can fail many times and merely cause annoyance. This is not one of those. It must be addressed.
More importantly. Now I know that these plates can break BEFORE any other part in the entire steering assembly, belying the basic design principle that the most crucial part in any assembly should be the one that fails last. On the other hand, as it should be the last to fail, it can be strengthened to any degree without effecting other parts or the Sequence of Failure.
MY SOLUTION: Unlike so many of the Morgan aftermarket predators that have appeared in the last decade, I favor simple bullet-proof non-invasive solutions, in keeping with a 1930s (Golden Age of Automolbiling) technology car. I had an extra center plate left from an earlier R&P Morgan but I intensely dislike using a part that I know now is capable of failing, disasterously. How many times does a disaster have to occur to be tragic?!!!) So I designed something more far more substantial and smarter and made it up. I replaced the plate with a new center plate using a stainless steel grade more capable of sustaining ANY possible stress or impact that the steering assembly could possibly encounter or produce over time or wear. .
I chose Type 304 stainless steel as it is rust resistant, durable and far more likely to bend than shear like the Morgan part. It is easy to make at home or small machine shop fabrication. It is easy to clean. It can be polished to a mirror finish.
also increased the stock used to 4 mm rather than the 3 mm (1/8"?)
stock Morgan used for the original.
I also reinforced the plate I by welding on side gussets to reinforce the
bends and I heated the bends before shaping them. My end product is
MUCH stronger than
the MMC affair. I no longer worry about a reoccurence.
This was added after the part of the article above brought the customary
wave of article feedback. It allowed some light to shine on why plate shearing
is rarer than one should have thought it would be. It showed that there
IS a possible spot that will fail before the plate and is likely inter-related.
The feedbackers, who had rushed to check their plates, did not notice anything
amiss with any. Of course, it would be only by very lucky coincidence
that someone would catch a plate before in the process of shearing. It
is a process that takes very little time from start to finish so there
is normally little if any warning. However, many souls have reported that
there was play at the steering wheel and/or they discovered their lower
bolts on the plate, those holding the tierods, had loosened significantly,
despite the lock tabs being installed properly. Here is an example.
The sequence seems apparent. If the nylocs ARE capable of holding (with the application of the right loctite or with lock tabs of their own) then the entire stress is transferred to the plate itself, and, in some cases, it shears. Neither event are happy results as the control of the car is lost
Stover Nuts are vibration resistant self locking nuts.
I use stoffer nuts to replace the untorquable nylocs the MMC use in critical areas. These include the axle u-bolts (where proper axle nuts cannot be be used for clearance reasons and the nylocs loosen as a sad tradition. I also use them at the propshaft.
N.B. A stoffer nut will run smoothly until it reaches the deformed part after which the clamping force will subsequently increase and require effort to thread.
of FAILURE: All
moving parts fail..eventually. So ideally, parts in any assembly (and each
individual assembly itself) should be designed and made to fail in a specific
sequence, with the most critical parts failing last. In this way, safety
is enhanced and damage pre-controlled. That is why we are so often instructed
to replace many parts in an assembly when one fails. In doing so,
we are trying to preserve the proper sequence of failure.
However, amateur (and often "professional" mechanical designers will often replace a failed part with something much stronger they have made themselves. Without careful examination and understanding, that replacement can change the sequence of failure and increase the risk of much greater damage.
by Lorne Goldman
I imagine this bit will also cause protests in some corners. I acknowledge that there have been many who have written sagely and with great solemnity on this subject. They have pondered for decades on such sundries as to whether the tie-rods should be afixed atop or below the stub axle arms, or how much longer the rods should be to minimize bump steer.I am sorry for them for this bit. Indeed, many in the new predatory aftermarket have convinced owners to spend silly sums of money and effort curing it. Even the older significantly more honest aftermarket will sell cures (much less expensive) to those that have been convinced to fret about it. But they confide to me that their cures are out of kindness and a recognition of the psychological relief they provide. (wry smile)
However, the truth
of the matter is that the famous flexing of the Morgan chassis makes
bump steer unimportant..a non-issue..or at least impossible to deal with aside from car by car.
Whenever they-who-wish-to-apply-other-automotive-technology consider the Morgan suspension and steering, they omit to factor in the impossible-to-quantify, namely the flexing of the chassis. This flexing not only varies from chassis to chassis, car to car, it also changes with each model and each car over time/usage. Measures that are designed for one car will not help another except by coincidence. It may even cause a prejudice. Imagine designing something for an old well-used 4/4 and transferring it to a later heavier Plus 8 or Roadster!! However, the newer "experts", are reluctant to admit or even acknowledge the most salient and influential component on the car. The chassis and the open top which have to individualize every car. But individual cars cannoit generate one-size-fits-all profits...so the convince the market that all Morgans are identical.c They plunge ahead, trained and limited by an education and training that applies to the type of chassis of other vehicles use. Indeed, sometimes their kit will be an improvement to a varying degree from car to car, sometimes it will add nothing and just as often it will prejudice the suspension.
It is for you to decide, for yourself, whether you think all Classic Morgans are a bit different or identical. Ask THAT question of your peer group! Sadly, these things have become "poltical" rather than decided by common sense. Too little savvy and too much money. :(
There is a wonderful Peter Morgan anecdote that is germane. Some 70 years ago he fit shocks to the Morgan front, fit alongside the kingpin springs, just as they are today unchanged since then. When asked whether they improved the handling or the ride, PM shrugged, indicating they had no effect that he could discern. But he confided that buyers were concerned as they saw them on other, different cars..so he slapped them on. ;)
One day, for your own amusement and in memory of Peter Morgan, remove your front dampers and go for a test drive.