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XK Body Alignment

XK Body Alignment

by Wray Schelin

Hello Neville,

As you have said in your last several postings you are having trouble
getting correct alignment of you body panels on your XK 140 OTS.You
seperated the body into the front half and rear half because the sills
and shut pillars needed replacing. The plan was to install the new sills
and shut pillars and everything would be fine. You discovered that your
door hinges needed help and I don't think you mentioned it yet but I,m
sure your cowl support stucture was weak with rust-outs also. So far
everything you described is common to all XKs except those very few that
spent their lives in dry climates or pampered garages. A carpentry rule
is "measure twice saw once". A body assembly rule is "measure,fit,check,
tack weld,measure,check,and lastly weld".Don't weld anything unless
you know exactly what the results are, and just like chess you have to
anticipate  three or four moves into the process. All the parts are
interelated. An eighth of inch mistake at some point in the process
might look insignificant but further on down the road you might find
yourself one inch off and if you've welded parts in you have a big
problem.

You are right in using your frame as your assembly jig. One precaution
is to check to make certain that your frame is straight to begin with.

Your sill replacement method that you described is the most common
method of repair.At first it looks like an easy way; "all I have to do
is work from inside the cockpit and I can easily slide these sills in
and I'm done". Then the hinges cry out for attention and you say,
"there's got to be a better way". There is remove the front fenders!
When you remove the front fenders you accomplish lots. One, you have
total access to the cowl support stucture. Two, the hinge repair is now
a snap. Three, the front fenders which almost always need attention now
can be put on the bench and worked on in a normal manner. You'll save
lots by not having to pay your chiropracter to adjust you out of your XK
contortions. You protest, "taking off the front wings is a lot of
unneccessary work and its difficult". Lets get serious here,your car is
laying in pieces all over the garage already you don't have to justify
this to anyone. Part two tomorrow night.

Regards,

Wray E. Schelin



Neville L wrote:
> 
> Wray or anyone else,
> What's the size gap I should be aiming for between the front of the door
> and the front fender,and the rear of the door and the rear fender.
> Give a range if you like, Good, average and max acceptable.
>  Neville Laing

Hello Neville,

 To address your current question first. The gaps between your door and
fenders should be three sixteenths of and inch or .1875". The paint
should be entirely removed when setting these gaps. A 3/16" diameter rod
will function as a good gage tool. Three sixteenths is ideal because the
gap will close up as you paint the car. Finished gaps with paint should
be at minumum 1/8" especially on the doors. Railroad tracks, potholes,
and speedbumps will chip off your paint at the rear of the door if you
tighten the gaps to much. The boot lid gaps are more forgiving. Even
gaps is a sign of a good body restoration.

I 'd like to make a few comments also about the door hinges. All XK door
hinges are alike in design but they differ a little between models. The
hinge has two parts; the hinge box and the hinge arm. The hinge box is
made up of two C -shaped twelve gage (.105") peices of sheetmetal joined
together 3/4" apart by four standoff seperators . The hinge arm is
connected to the box with a 5/16" dia. shouldered hinge pin.

No provision was made for lubrication of these hinges and the design
incorporates a steel hinge pin riding against a nonbushed steel hinge
arm. Is it to late to file a class action lawsuit for this egregious
design flaw? Perhaps the engineer responsible has had many sleepless
nights.

The hinge fails in several ways. Rust welding of the hinge pin to the
hinge arm is the  most common occurrence. When this happens the
shouldered hinge pin starts to turn in the hinge box. I have had
countless calls from customers asking how to remove those stuck hinge
pins. If your doing a total restoration I always say "remove the front
fenders" and then everythings accessible. I know thats an unreasonable
solution if all your trying to do is tighten up your doors so that they
shut good . In this case I say remove a portion of the hinge panel and
weld it back in later. If you do that carefully you can limit your paint
damage to the hinge panel only, which can be easily touched up. Once out
of the car the hinge assemblies can be easyly rebuilt and improved for
long life. I sell an inexpensive rebuild kit which includes a stainless
steel shoulder pin, a self lubricating oillite bushing for the arm and a
stainless nut and serrated washer. To repair the hinge assembly you
first remove the pin with heat from an acetylene torch. Then you must
weld up the hinge box hole where the pin has turned in it and enlarged
it. You clean up the weld and rebore the hole back to its standard 5/16"
diameter. The hinge arm  is bored to 3/8" and the oillight bushing which
measures .376" is presssed into the arm. Then grease the the moving
surfaces and reassemble.

I'll get back to the body alignment tommorrow, also I sent Mike Ramsey
four pictures of spats for wire wheel cars and a picture of aluminum
belly pans.He should be able to scan the pictures by the weekend.
I will have a posting describing the pictures and also the information I
got from Jaguar friends.

Regards,

Wray E. Schelin




Hello Neville and everyone,

A discussion of body alignment of XK Jaguars would be remiss if it
didn't include a little background history . As I said before, most of
my restoration experience has been with Classics from the 1926-1941
period. The luxury cars of this period had custom bodies built by
specialist firms such as Murphy, Lebaron, Derham, and many others.
Typically these bodies had ash frames skun with aluminum and had steel
fenders which were usually stamped by the manufacturer; then the
coachbuilder would sometimes modify the fenders to fit into their
proprietary body design. If a design was particularly attractive a dozen
or two copies would be made. This method of construction was expensive
because of all the skilled labor needed. Craftmanship was often a point
of rivalry between competing coachbuilders with the result being  a very
high standard of fit and finish. The high level of fit and finish was
not engineered into the product; it was a direct result of tedious
trail, fit,and adjust cycles on every part.

The Depression and the war finished off most of the luxury car
manufacturers and coachbuilders. It was 1948 before most manufacturers
were tooled up and back in business. The fit and finish of the immediate
postwar cars were generally poor with some exceptions. Jaguar had made
the transition with their sedans from ash frame body construction
methods to all steel, stamped ,and spot welded construction. Jaguar had
developed a high standards reputation as a manufacturer and incorporated
skilled hand work into their body construction methods. All panel seams
were carefully leaded and gaps were evened with lead to improve fits
(techniques that were carried over from the earlier coachbuiding era).

Initially XKs were built using a modified ash framing and aluminum skin
construction method but Jaguar was forced by a strong market demand to
rapidly tool up for a stamped, all steel body with the exception of the
doors, bootlid, and bonnet.  As to how good the fit and finish was on
the XKs when they were new in the showrooms, I can only ask for the
testimony of those that saw them when they were new, for, at the time,
I was driving a tricycle. A friend of mine has told me that Road and
Track magazine was always praising the performance of the XKs but
critizing the fit and finish. My opinion is that some cars came out of
the works nearly perfect and others with many flaws.

Outstanding body panel fits today at most manufacturers are routinely
being acheived by engineering the variables out of the design. They do
this by using computer guided quality control methods and most
importantly they stamp the whole structural side of the car one
piece eliminating countless possible sources of variables derived from a
welded assembly.

To acheive excellent body fits when restoring XKs today the skilled
methods of the earlier coachbuilders have to be adopted. The task is
further complicated by the fact that the cars have already gone through
a product life cycle with typically rust ,accident damage, and
worst of all bodged repairs. So the question of " how do I align my body
panels" is not always and easy one .The most important skill necessary
is patience.

Part four will deal with the methods Jaguar used to assemble the XK
bodies.

Regards,

Wray E. Schelin



Neville L wrote:
> 
> Hi Wray,
> I agree that your previous postings on alignment have been excellent and
> I for one want to encourage you to keep going. I am making slow progress
> in trying to get handle on the problems I have. One of the problems I
> have is with the door looking good at is connection to the front fender,
> the gap at rear of door to rear fender varies from one eigth of an inch
> at top of the door to half an inch at the bottom. Bear in mind that the
> shutface panel is not welded in yet, and is only bolted to fender at
> present. I am sure the solution lies in moving fender around, but I am
> hoping you will have some quick an easy solution for me.
>         There has been some discussion about engine numbers, can anyone 
tell me
> of a publication where Gearbox types are tied to either chassis numbers
> or engine numbers.
> Neville Laing

Hello Neville,

I think I can best answer your immediate question by continuing on with
the a general decription of XK body alignment and if you have any
specific questions after that I'll be glad to try to answer them as they
arise.

The most important components in terms of alignment of the XK body are
the front fenders,sills, shut pillars, cowl assembly or in English
nomenclature scuttle assembly, and the rearbody assembly.Consider these
components as primary or standard setting.The remaining parts the
bonnet, doors, roof(FHC),boot lid, and the rear fenders have to fit
precisely into their respective places.They are secondary. The secondary
components are good markers of misalignment. For example if the cowl
leans rearward just a sixteenth of inch(at the top hinge location) your
rear door gap will be wide at the bottom and narrow at the top.

If a company is going to mass produce any thing they have to make
dedicated tooling to make the procees as simple and error free as
possble. Tooling to make the individual components and tooling to
facilitate easy assembly of many components into a sub assembly and then
finally a complete assembly.

The cowl assembly of the XK was probably the first sub-assembly built
and the cowl assembly was the determining factor on the body type. Many
peices make up this sub-assembly. And elaborate fixture would have to
hold the peices in alignment and then the welder using an articulated
hanging spot welder would do his job.  Two methods that Jaguar used to
facilitate alignment was the use of guide holes and pop rivits. On alot
of the components you will see punched three eights diameter holes. I
suspect that these holes were punched when the part was made. The holes
were then utilzed by the welding fixture as a true alignment point
assuring a repeatabity that was simple and fairly accurate. They also
used pop rivits as a pre joining method. You will find aluminum pop
rivits in many places and they seam to have no function.

The cowl assembly which includes the firewall, outer cowl body skin,
windshield posts or mounting points, under dash stucture, and the cowl
support stucture. It is the cowl support stucture, ( the C shaped sheet
metal columns on the outer sides of the cowl assembly) that make the
interface with the outer side of the frontal area of the sills. You will
notice, providing it hasn't been removed, an L shaped piece of sheet
metal welded to the inside of the cowl support stucture resting on the
top of the sill. This provides a depth stop when the cowl assembly was
eased on to the sills for joining. It also maintains a side to side and
front to back balance of the cowl assembly. If this part is missing a
easily adjustible substitute should be installed. Without something
there to support the cowl assembly it will be free to rock in any
direction. The thing to do if its not there when disassembling is to
install something before disassembly ( for instance if your removing the
sills only) at least you have a close starting point then.

Part 5 Body alignment later.

Regards,

Wray E Schelin



Neville and Everyone,

My last posting on body alignment stressed the importance of the cowl
assembly positioning relative to the sills. The cowl assembly is at the
front of the sills and the shut pillar is at the rear. Between the two
the door must fit perfectly. Islolate these assemblies from the rest of
the body components and you will see that body alignment starts at the
center of the car and progresses out simultaneously to the front and the
rear.Jaguar had the use of jigs which were designed to be very rigid and
they could attach to the prewelded assemblies easily and also provide
ample room to allow welding without obstuctions. The only alignment tool
that we have available is the frame. In my opinion the expense of
creating a body assembly welding jig - and for it to be of any value it
would have to be as accurate and strong as what Jaguar had created -
renders this option all but impossible.

The shut pillars attachment to the sills is a very complex arrangement
because of the many angles that are involved. As I stated in my previous
postings on this subject don't get ahead of yourself by welding any
thing until your absolutely sure of the alignment.Use clamps,clecos,
small tack welds, or pop rivits to temporarely hold things together
before finish welding. Door alignment gaps are your guide markers. If
your gaps are off , adjust untill they're right.

As Dick Cavicke correctly pointed out make sure that your frame is
supported from the suspension otherwise the frame will flex. Also you
should have the frame on a level floor or leveled supports.

I frequently hear customers accounts of the progress of their
restorations. They usually recount how they have finished rebuilding the
motor and chassis. "The chassis is a roller now and all I have to do now
is the bodywork" they say. Body recontruction is a dirty, dusty,and
trying task it makes a lot more sense to tackle the body first on a
cleaned and derusted frame but not a fully restored one.You might say
"thats no problem I have a spare frame that I'll use for the body
reconstruction." This is risky because all frames will differ slightly-
some of the difference would have been present at the factory(very small
amounts)and some will be present from various accidents that might have
occured. Check your frame very thoughly for hidden damage. Frames can
also sag or relax in the middle because of excessive rust.

Ideally you should be able to stand back (ten to fifteen feet)and look
at the body from many angles as the work progresses. Good lighting and
ample walk around room allows you to spot misalignments before you weld.
With the frame leveled the body should look right from every angle.

Part 6 Next  - Door problems and welding techniques

Regards,

Wray E. Schelin

WES PARTS     I fabricate new sheetmetal parts for XK Jaguars
P.O. Box 652            Phone 508 347-7749
Charlton City, MA 01566



Hi Neville, and all,

I hope everyone had a memorable Thanksgiving. I guess I wasn't the only
one missing the daily dose of XK e-mails. But now its back to the garage
to ponder how all those parts fit together to make a beautiful XK.

This installment , covering welding techniques and XK door problems,
will wander a bit from the subject at hand ( body alignment) but I think
it deserves attention.  If anybody is interested  in more information on
these subjects I will share my experience in greater depth later.

I understand that not everyone does their own restorations but I have a
lot of respect for the ones that do. One of the problems of restoration
is that you get very few chances to do a specific procedure in the
process of restoration. For example on a 120 OTS if your trying to
decide whats the best course of action to take with your doors. You know
the doors are a critical element in the alignment of the car. You also
know that your doors have plenty of faults, most do. Replacing the doors
with good used ones ( better than yours) is fast becoming impossible.
Very few XK's are being parted out today and excellent used 120 parts
are just about nonexistant. If your doors are not to bad you might be
clever enough to make suitable repairs. You can also order new hand made
ones .

What do you do? This is the trickest part of restoration and also the
source of many misjudgements which can effect the whole process. Since
your only doing this restoration once,you don't have the benifit of
repeating a procedure to learn through trail and error what is the best
way to solve the problem. I will say in all honesty that at my
grandfathers restoration shop we sometimes had to do things three times
to make them absolutely right. Thats just the way restoration is accept
it. If you specialize in say just 120 OTS restorations and do lots of
them you probably can get things 99% right first try. Patience pays
dividends.

 Back to the doors. 120 and 140 OTS doors are monocoque aluminum
structures. That is the door frame and skin work together sharing loads.
The doors are a marvel and do their job well but they are very vunerable
to any abuse. If your door is typical, the hinge panel at the front
where the lower hinge attaches, will be ripped and probably already have
some sort of jerry-built repair present. Leaning on the back of the door
will cause this failure. Another common fault is streching of the door
skin in the flat portion. Slight accidents and I believe mostly bodged
repairs account for the over-use of bondo in this area. The inner
structure will also start to crack at stress points because of
overloading brought on by the failure of the hinge panel and skin.
If your doors have these problems you have to solve them first before
welding in new sills or shut pillars.

The 120 FHC, DHC, 140 early DHC, and 140 FHC are all of traditional
coachbuilt constuction, that is they are hardwood frames skun with
aluminum and sometimes steel skins. With this construction method the
doors are less vunerable than the OTS doors but they are subject to wood
rotting problems usually confined to the bottom area where moisture
would collect. If the wood structure starts to deteriorate the skin will
start to carry the loads and crack at stress points. If you try to weld
these without fixing the stucture the cracks will probably come back.

The 150( all models)and late 140 DHC are all steel monocoque
constructions and are like most car doors made today. Being all steel
they are subject to heavy rusting in the lower six inch region. Usually
the skin, hinge panel, lock panel, and the inner kick panel are
affected.

In conclusion  body alignment is all interelated and has to follow the
right order of progress. If you don't address obvious problems first
they can mislead you into a compounded problem later on . In my opinion
the first step in any restoration should be fix your doors first and
make sure they're right.

I'll get to the welding in part seven, I'm too exhausted now.

Regards,

Wray E. Schelin

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