rear sway bars
 

Need some pictures of rear swaybars and how they mount so i can figure out how to make my upgrades trailing arms and differential support mount. Anything would be helpfull

........ there arent any. at least, no one on this forum has an XJS thats old enough to have rear sways.


Mish's xjs might be old enough, but i dont think so.

You might already the two stud plates in the floorboard that the U-brackets bolt to. If so, you just need to weld a couple tabs to the trailing arms to accept the end links.

Here are some pics. I'll try to find others

Welcome to Jag-lovers - Members Photo Viewing Page

Not sure what you mean by "differential support mount"

Cheers
DD

Here's a good pic of the rear arms with the little brackets on the small end

Jaguar XJS Rear Radius Arm Assembly with Bushes (C41831*) | JustJagsUK.com


Cheers
DD

As standard, from the factory, the presence or absence of rear anti-roll (USA = sway) bars, was a continuing story of fitted and not fitted. Only the 6 cylinder cars with sports pack suspension were always fitted with them.

As Doug said, the bar was fixed to the body above the diff/prop shaft, on the sloping bit of the body in front of the rear axle, by two brackets just like the front ones, that were fitted to studs protruding from this part of the body, with rubber bushes round the bar. The bar had a right angle backwards at each side the end of which bolted to the radius arm as shown in Doug's link photo.

FWIW, I believe the V12 handles much better without the rear bars, providing that the rear ride height is not too high and providing that the rear wheels have 1/2 to 3/4 of a degree of negative camber (adjusted by removing shims from the inboard driveshaft to diff coupling flanges). On my car this combination gave very progressive break away characteristics and very responsive adjustment to steering and power inputs.

Greg

Many agree.

I prefer the flatter stance so the rear bar was good for me. I'll say from experience though that a too-big rear bar is definately a bad thing on an XJS.....unless you *enjoy* very sudden breakaway at the limit!

I found that if a 4000 pound Jag gets away from me it's very hard to reel it back in :-)

After experimenting with different bars, if I had to do it all over again, I stick with the smaller standard bar...which was only 9/16th inch as I recall. You'll still get much flatter cornering and less understeer...but the car will remain predictable.

Cheers
DD

i was going to go with the one from fasterjags, and i already have the trailing arms, but i was planing on making trailing arms that mounted trianguraly to the frame rails of the car to make the rear suspension have strait up and down travel. If i can find a pic ill post it

This thread is the best I've found so far with regards to pictures (via the Jag-Lovers link) on where the Rear ARB (Sway) Bar Brackets should be located. That said I'd really appreciate it if anyone either the original fit or an aftermarket fit Rear ARB fitted to their XJS/6/12, if they could post up some more pictures and or dimensions of the brackets in relation to the chassis.

Yo very much appreciated!

Woz

See post #4 in this thread.....although not much is revealed

https://www.jaguarforums.com/forum/x...tinued-177670/

Cheers
DD

I wouldn't be surprised of the mounting holes are already there. My 94 V12 came from the factory with a rear bar. The rear ARB seemed to be an on and off again thing, depending on market and year. All the parts except the bar itself are available from Jaguar. https://www.jaguarclassicparts.com/u...bar-sportspack

My 1989 has the body mounts for the rear sway bar but not the radius arm mounts.

The body mounts will up under the back seat.

All XJS coupes, or at least all I have seen, have studs, not bolt holes for the rear ARB, placed as Warrjon said, in the forward slope of the rear axle hump in the bodywork. Your series 1 XJS very likely did not have these studs fitted.
The radius arms, for the XJS at least, can be bought with or without the fixings for the ARB droplinks.
https://www.jaguarclassicparts.com/i...ges/mh7221.png

Unlike the XJS, a rear bar was never intended for the Series I-II-III sedans so Jaguar never bothered to pre-install any of the hardware.

If opportunity permits in the next few days I'll take some location measurements from my installation.....which, frankly, wasn't the least bit scientific. I did a mock-up and drilled holes for the U-brackets taking into consideration where the surface of the floor pan was flattest, clearance for the ends of the bar, and other things which I've forgotten at the moment.

Cheers
DD

These pictures are not great, but show the location I used on a S1

Welcome to Jag-lovers - Members Photo Viewing Page


PS I have rear original bar for sale.

Rob

My 95 4.0 XJS coupe does not have the studs fitted in the floor under the rear seat, nor is the reinforcing steel plate installed on the underside of the body for the "U" brackets. My radius arms do have the mounting ears for the sway bar down links.

Best I can measure, the mounting brackets are 31" apart, center to center.

my XJS had the ARB , fitted 1978 V12, but talking with some local guys who raced the early XJS said to take it off,it will handle better!
so i been runnin round that way for 26yrs! i never drove the car when it was fitted , so i donno!
ron

Same old story, though. What works well on the track might not be ideal for street use. I feel safe in saying that the vast majority of people who add or upgrade anti-roll bars (on any car) are happy with the result. It's certainly possible to go overboard, though.

Jaguar itself apparently had difficulty deciding if the rear bar was worthwhile. All the pre-HE cars had one. After the HE was introduced the engineers (or accountants?) were very selective about using 'em.

Cheers
​​​​​​​DD

I am with Ronbros on this one. providing there is some negative camber on the rear wheels, and that the ride height is correct, I believe the XJS handles and corners better with no rear ARB.

I've heard this before, I spoke to one racer name Charles... he disconnected the bar at a Lime Rock track day and on the next lap out picked up a second or two. Hard to tell if that was driver variation or if it helped. Who knows? Lime rock is one of those tracks you slide around and the fastest laps can sometimes be slippy and sloppy. Every track is different.

The XJS understeers, Having the rear end flop over can help the car rotate in experience hands. On the street, under-steer is generally considered safer.

The better setup is to keep or install the somewhat thin stock rear bar and upgrade to a stiffer 1 inch front bar. This will make the back end soft relative to the front and offer up a more controlled rotation effect. I have driven a friends 1990 XJS with this setup and it's a great drive. He managed a 1:16 on a Limerock track day which is a good time for a novice in any car. The brakes over heated after 2 laps and Limerock isn't even a brake intensive track.

The Aston DB7 GT had a slightly larger rear sway bar and 1 inch front. That's the setup I use and the DB7 GT put down a good time for GT car at the Nurburgring Nordschleife. About 8 min. That's Amazing becasue that time was in line with other high end GT offerings of the day from Porsche and Ferrari. Many people dont know the DB7 was based on the XJS but the Front suspension geometry is more inline with the XK8 than a XJS.

i did install a 1" front bar ,when i took the rear off, way back 1994!!

truth is i dont drive really fast anymore , i'm turnin 85 this year, so gotta think about sellin the XJS HOT ROD!
i know ,but ever think what the hell would my wife do with it?
perish the thought!
ron

my understanding about the XJS , with a stiff rear bar, is breakaway happens suddenly , and collecting it up is difficult!

altho who drives like that anyway?

'Tis true.

On my XJS I had the 1" front bar and experimented with 3 different rear bars.

Jaguar used two different sizes in the rear, 13mm and 15mm....or something like that. I found and tried both. I also tried an Addco rear bar, which is something like 19mm.

The Addco bar was too much. The car became borderline treacherous.

Both of the smaller sizes were fine; the difference between them, subjectively, was not significant.

Cheers
DD

My XJS has a 1" (25mm) front bar and 7/8" (22mm) rear bar and it corners very flatly. The only time I have had oversteer is applying power in the wet on a corner, never a problem in the dry. The factory bar is 16mm rear I believe, paired with 22mm front.

I think you will have trouble fitting a 27mm front bar actually, as the 25mm leaves very little wall thickness of the bushing that goes into the brackets. I'm not sure you could fit bushing and a 27mm bar into the factory brackets.