First of all, I'm a fairly new member (ie. never posted before) and I've been searching on Google and on here about how the XJ6 is built...as in the body and frame/backbone and skin.

Is there anyone out there who can give me a heads up on where to find detailed info one the construction of the XJ6?

Thanks in advance!

 

Welcome.

The XJ6 is uni-body or unit body chassis and has no frame or back bone. The body panels are constructed in such a way that when assembled they make a somewhat rigid structure. There inst much documentation on how this is done for a XJ6. You may want to get a copy of the parts manual which shows an exploded view of replacement panels, I have attached what I have.

 

it is called unibody construction, unitary body-chassis, or integral body frame.

the body and chassis are one, no separate chassis,

the exterior panels or skins provide little if any strength or stiffness to the finished body.. it is the box sections, bulkheads and tubes which produce the strength of the unit.

this is not "monocoque" construction, that is a different approach to car building.

Jaguar started with this technique in 1955 with the MK-1, then followed by the MK-2, S type, MK-10, 420, 420-G, and from 1968-on, all XJ

 

Jose:


I am not an engineer by any means. Unibody and monocoque are very similar f not the same. a method differing from olden body on frame construction.


And, the skin is an important part of the structure. it performs as a diaphragm that resists wracking of the geometric sections formed as you say by tubes and box sections. The bulk heads are diaphrams as well.


Think of a cube made up of 2x2 material, alloy, steel and even wood. Pretty strong.
exceeded only by a sphere. Well, a sphere is strong via it's skin. Add sheeting to the cube. As strong as it gets.


Think of a frame house. Bare wall studs, floor joists, and roof joists. EQ doomed. Add sheathing, aka diaphram. They do well in EQ's. Local codes very demanding in that area.


The Jaguar body is immensely strong, although quite heavy.


No "body off" restorations here.


I think the last of the body on frame cars was Ford's Crown Victoria and derivatives.


Carl

 

Jaguar as a company could never afford to use large pressings as the tooling would have cost too much. So the XJ is made up of a large number of fairly small pressings. Remember the XJ saloon body was designed in about 1966/67 and used the same techniques used on the previous body shells, so there is a lot of body lead used to fill joint lines in various places. When I replaced the rear valance on a Series 3, I first had to melt off the lead to get to the spot welds just below the boot aperture.

 

Hi there, my first post as well. If you're attempting major restoration/welding, especially, if you are considering to replace inner/outer fills or floor pans make sure you prop and brace the car. On my S2 coupe, I made the mistake of changing the floor, inner and outer cills without bracing and ended up with the car being 5mm short on the driver side. Driver's door jamming on the rear wing. I searched high and low for body measurements but to no avail. Bought another S2 Coupe and I'm in the process of making a jig to get the measurement from the second coupe.
Time allowing, I'm hoping to do this in the coming few weeks. Once I'm done, I will post measurement and pictures.
It's worth noting that S2 andS3 is about 100mm longer than the coupe. Hope this helps

 

Fraser:


Yes, it was also an issue in the USA. Up until about 1925, all closed cars had top inserts of wood and fabric. Then, large presses became available that could stamp out an entire sedan roof in one piece. The turret top was born that was feasible on the fast paced assembly lines.


At about that time E. L. Cord and Gordon Buehrig designed and produced the famous coffin nosed cord. It's body was built of many much smaller stampings.
welded together and seams leaded.


But welded panels and leaded seams continued for much longer. Not sure about present robo built cars!!


Work on mine going well.


Carl

 

Excellent pics from ICS, and thanks to David from EverydayXJ heres what it looks like in practice (there are pagination controls at the bottom)
http://www.everydayxj.com/Anatomy_of_a_Series_3_XJ.ph

 

Just noticed the mentioned link was broken... Here is a good link:
Anatomy of a Series 3 XJ

Thanks for the mention...
David
shop.everydayxj.com