The Morgan Rack & Pinion Bible (rewritten for my friend Bill Button in 2016)
by Lorne Goldman

1.    Safety
2.    History

3.    General
4.    Turns-to-lock
5.    Changing the Centre Gaiter 
6.    The Center Gaiter
7.    The End Cones

8.    Adding Lubricating Fluid

9.    Steering Play 
10.  The Internal Spacers and the Channel
11.  Centre Plate to Rack 
12.  Center Plate Splitting
13   The Lock Tabs 
14.  Tie-rods to Center Plate
15.  Securing Blocks
16Jack Knight Switching Sides 
17.  Widening of the Rack Channel, Effect & Cure
18.  Using the Adjuster 
19.  Bump Steer on Classsic Morgans

SAFETY

Every vehicle has the same three component systems that form the first line of safety for the occupants. They are tyres, brakes and steering. There can be no compromises entertained with any of them. Happily, Morgan trads are very wondrously simple in these areas and the task to keep these areas safe is not difficult or cumbersome. However, 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! If you have any doubts whatsoever, consult an experienced Morgan dealer. Happily, the key safety 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.

HISTORY

In 1983,  the Morgan Motor Company, thrrough Maurice Owen, approached Jack Knight Ltd., a noted British aftermarket steering specialist. JK was asked 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. In fact, the Jack Knight rack that they turned up was not originally designed for Morgan. Jack Knight already had something available which could be adapted. It was from the MG Metro 6R4 rally car. Bit of machining and they made it fit. That is why the centre casting is magnesium.

The resultant rack, with all its pimples and problems was still 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 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 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£. 

In 2007, Jack Knight Ltd, the rack's designer and manufacturer since 1983, ran into business problems and Morgan had Quaife provide replacement copy. The racks are very similiar. 

TURNS TO LOCK

The Morgan Motor Company had the stock rack's turns-to-lock changed a number of times during its history. The Jack Knight rack can be had with 2.3, 2.7, 3.0 or 3.5 turns to lock and the choice will be one major determinant, of the compromise between steering reactiveness or ease of steering. As well, the Jack Knight rack takes only a short time to switch from LHD to RHD or back!

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 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.

CHANGING THE JACK KNIGHT CENTRE GAITER
by Lorne Goldman

If you can, the gaiter is best changed with the rack in situ and 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.

1. 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 back)

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.

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. 

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. Do not forget anything or their order in the attachment sequence. 

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 end cones,  use the right-sized tie wraps 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. Note.

THE JK CENTER GAITERS  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, including me,  looking into a higher quality gaiter, easily sourced and reasonably priced. Watch this space. 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 demostrate your one-shot oiler to them either!!! 

THE END CONES

These are the two cone-shaped "gaiters" at each of the rack. They hold in the lubricating fluid. They are thusly shaped to allow the pinion to move outside the rack..something it dows when you turn significantly enough to either side. Herein lies an important factor in installing them. If you you position them to much inboard, the first deep turn you take wwill puncture them land allow lubricating fluid out and grit in! And at least one has to be regularly removed to add lubricating fluid at major tune-up time.

ADDING LUBRICATING FLUID

To add lubricating fluid, I jack the car on one side to tilt it, I turn the steering a bit to recess the pinion on the lifted side, remove the cone, fill the cone with my lubricating fluid of choice and then fit the cone back on without spilling more of the fluid/grease than I have to. One cone a year is enough. I have used many types of lubricant, 80-90 hypoy, chainsaw chain oil, etc. All of them have worked fine but for those who are into super fine details, here is what is recommended for the latest racks.

The original approved lubricant (used in manufacture) was BP Energrease FG 00-EP since it is a compatible with the application and gaiter material.  The specifications were:

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.

Application

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°Cto100°C.

Advantages

-  Overcomes leakage of lubricant. 

- Suitable for a wide range of gearbox applications, irrespective of the attitude in which the gearbox is mounted 

- Eliminates dry start-up 

- Allows extended maintenance periods 

- Exhibits excellent shear stability, oxidation stability and load carrying ability 

- Reduces noise 

- Improves reliability

The approved lubricant above is not longer available. Here are current alternatives.

Mobil Mobilux 2

SKF Alfalub LGMT

Shell Alvania R2 or G2

Esso Beacon 2


THE INTERNAL SPACERS
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).

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 for a center gaiter.

WEAR IN THE CHANNEL

Yes. It happens. Happened to me in 1997 with my first Plus 8. After 35,000 miles or so, there is a possibility that the channel of the Morgan rack & pinion will wear open, tapering to each side from the center of the rack channel. The spacers (see diagrams) that hold the center plate bolts and therefore the center plate nice and snug in the channel will no longer be snug at the center, meaning the plate will have up and down movement. Center your steering, grip the plate, and move it up and down when the front of the car is off the ground. Now have someone turn the steering to one side or the other and try to move the plate up or down again. If there is a difference in the possible movement, you have found the culprit.

There is no need to spend 1500 to  buy a new rack unless you are anal. I simply went to the nearest machine shop, had them even out the channel and make new and larger spacers to make the whole thig snug again. One watchpoint, you will notice the Morgan spacers have a raced circlet in the center of the sside facing outward. This prevents the delicate gaiter from being crushed between the plate and the spacer. Rather than machining a circlet, simply used a same sized wsher between the centreplate/gaiter/internal spacer.

PLAY AT THE STEERING WHEEL

Morgan rack and pinion steering systems should have NO play at the steering wheel. None. De nada, Rien. If you have some, then something is amiss. 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, the entire steering system MUST be checked before driving further.

Many times a visual test will locate the problem. 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. To 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.

CENTER PLATE TO RACK

These two bolts go through a lock tabs, 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.  Read on. There is sufficent play in these bolt holes to warrant verifiying the wheel alignment if any looseness has been detected and cured.

LOCK TABS

hese bolts are supposed to be secured by lock tabs..but they 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 of these bolts as the tierods cover them. The centre plate tierod bolts, must be removed and the tierods moved away to allow for the 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. 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 hole in the pinion.  

I have a handy precaution I use. After tightening each bolt (outer and inner) on the center plate and then placing. closing their lock tab, I paint a small white line from a point on the bolt head to some adjacent reference point.  This allows me, with a quick glamce, to verfify that the bolts, inner and outer, have not moved.
 

TIE RODS 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 marking system on these bolts as well. There is sufficent play in these bolt holes to warrant verifiying the wheel alignment if any looseness has been detected and cured.

CENTER PLATE SPLITTING

Yes, it happened to me. Incredibly, it was at the end of a back country ride of over 700 miles, from Saute St. Marie,  Ontario to Labelle, Quebec in 2012. One of the best Morgan days of my life.I felt something strange happening to  the steering during the last few miles, but it was dark, the sent of the stable was in my nostrils and, side from a  quick glance under a highway light, I plungd on home. As luck would have it, my tie rods fell to the ground and the front wheels splayed in opposite directions as I was turning into my garage. My wife and duaghter hand held the front wheels to get me into my workshop. If the plate had fell off in pieces mere minutes before, I would be dead. Continuing on was one of the dumbest things I have ever done in a lifetime of dumb things.

To squelch any tendency for owners to throw themselves into denial, the entire rack and all parts, including the center plate, were Morgan original parts from 2003. The highways driven on that trip were through Quebec, Ontario, Michigan and Wisconsin. I do not rcall a single sharp bump.

BTW, the evidence indicated that, for a while at least, the bolts will hold a sheared center plate in place.

I did as I always do now when a Morgan part breaks. I no longer have a replacement from the Factory. After my first decade of Morgan ownership, it no longer takes me twice to learn a lesson. I examine the part and have a replacment made that will allow me to avoid the same experience, quite possibly saving my own life.  nN this case, I had a new plate machined, in a slightly thicker graded stainless alloy. I welded on side gussets to greatly strengthen the plate and the added thickness alloyed me to thread the plates themselves for the outer tie-rod bolts, which I supplement with nylocs. It is likely overkill. But these things are not expensive to do and I would rather overkill this vital part than kill myself.

To the left is an image of the broken 2003 plate, a picture of the plate off thated last much longer (off my 1984 Plus 8) and the new plate I made. To the right is an enlarged picture of the new plate I made.
NOTE: I do not have enough specialist equipment to confirm why these plates can break. However, since they shear at the bend, we can speculate that they are cold-bent. 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". 

More importantly. We do now know the plate 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. 


BOLTS THROUGH THE SECURING BLOCKS

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 indicated as assembled "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  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.  

There is sufficent play in these bolt holes to warrant verifiying the wheel alignment if any looseness has been detected and cured.

USING THE ADJUSTER MORGAN RACK & PINION SYSTEMS
by David Poole at the eMog Pub

The rack is produced by Jack Knight Engineering (UK) (http://www.jackknight.co.uk/) up to 2007 an then by Quaife Engineering.

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.   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. On the older cars, there can be wear in the rack channel. This can be remachined and a spacers made to fit. 

WATCHPOINT: I have been advised by Bill Button that he discovered an immoveable adjuster that prevented him from refining the play in the rack. After investigation by a machinist friend of his, they found that the nylon follower was so tight, it stopped any adjuster movement. A bit of machining fxed it. After adjustment, a tiny play of 1/4" at the steering wheel resulted.

BUMP STEER

I know this is going to disappoint many armchair theoreticians. It is certainly not going to make me any friends among the new predattory Morgan aftermarket, but honestly everyone, Morgans do not really suffer bump steer like modern vehicles. They have too much chassis flex to cause such problems or to solve it with a single one-size-fits-all if they did.