The 'E' Type Forum

I see that XKs Unlimited is offering a high performance sway bar kit for the series III that includes both front and rear. Apparently they have for some time now, but it wasn't until recently that I knew about it. No one else seems to sell anything like it that I know of. Anyone familiar with what sway bar can be fitted to the rear of a SIII? Is it from another model or something completely custom they have created on their own? I would love to fit one to my SIII for a bit more flatter cornering than the uprated front sway bar I installed many years ago provides.

Thanks,

Steve,
you will find that some E-types had a rear sway bar fitted originally, but Jaguar deemed that it wasn't necessary on the S3.
Clausager's book on E-type factory originality doesn't mention a rear anti sway bar for the S3 at all. A quick flick through the S1 and S2 pages showed no mention of rear anti sway bars.
Cheers ....... Ole

If anything, the rear sway bar from an XJS MIGHT work. Even on the XJS, they were not always fittted and, I believe, scarce.

My '80 pre-HE XJS does have a rear sway bar.

Try Harvey Bailey, they probably make them.

Thanks for the info everyone! After a bit more digging I see that SNG also offers a sway bar kit for the SIII and it consists of both the front and rear. There doesn't seem to be any offering of just the rear bar. I have already installed an uprated front bar many years ago and it has helped considerably. At that time I don't think anyone sold a rear kit.

The Harvey Bailey website doesn't have much information on it and considering I'm in California, the freight would most likely be more than it's worth.

I have an inquiry in to XKs Unlimited and maybe this coming week I'll hear from them. I'm also going to ask at SNG if they can sell just the rear portion of their kit. Time will tell!

Anyone else know anything about these seemingly rare anti roll bars?

Not ever original equipment on a Series 3 - I have seen modified XJS bars fitted but that was many many years ago.

As a lad I played around with sway bars. Not on E's. I found that to avoid nasty suprises i shoud test settings when the road was wet. In particular, a too stiff rear bar could cause sudden loss of traction and chaotic oversteer. Cheaper solution was to run tyres at max pressure ...

Update

I just heard from SNG this morning and they say they will only sell the complete kit.

I believe I read somewhere that the 2+2's (not S3's) got rear anti sway bars, but can not for the life of Mary remember where I read it.

According to the parts manuals, all series 1 & 2 cars had rear anti roll bars.

I don't have the series 3 parts manual but I'll bet it's on here somewhere.

Regards

It isn't and they didn't, but you ought to be able to locate the captive nuts above the IRS where it would have bolted into the body as these are a legacy item still present in 1974.

Expect to alter the handling if you attempt to fit one, as it'll upset how the front grips the road, not just the rear's ability to roll.

kind regards
Marek

At the risk of getting flamed.
Handling is a balance between the weight distribution, center of gravity, roll center, tires (contact patch and grip), alignment, and the front and rear suspension on a vehicle. Most vehicles are set up from the factory with the ride and handling characteristics desired by the designers. The XKE is a fine handling car in stock form.

I have a 1970 fixed head coupe. It came stock with a front and rear sway bar. The specification (part #s) for for the 2+2 chassis are the same for the front bar but different for the rear bar. The wheel base is longer and the vehicle is heavier by about 70 pounds. The front to rear weight distribution is different.

The series 3 XKEs are the 2+2 chassis. They weighed in about 340 pounds more than my series 2 FHC. They were equipped with wider wheels and tires than the series 2. I have no direct knowledge if they were factory equipped with a rear sway bar or not. So, I will go with the OP's post and information previously posted here.

Assume the car is in balance in stock form. Modifying the suspension at only one end of the car will throw the balance off. Sway bars have an effect on the roll center of the vehicle. In a front engine / rear drive car the front sway bar is usually a larger diameter than the rear bar (if equipped with a rear bar.) If you increase the stiffness of the front bar, the balance will change. This can be mitigated by installing a rear bar, or increasing the stiffness of the rear bar. Not maintaining the front and rear balance in roll center could result in under or over steer. Suspension suppliers sell matched sets that take the change in stiffness into account.

Anecdotal storiy: In the early 1980s, my friend inherited a 1966 Chevy Bel Air 4 door sedan. It was a boat that wallowed in the turns and at any speed understeered dangerously. He was planning stiff springs and shocks as the cure. That probably would have produced a truck like ride. I convinced him to first try a set of sway bars. The stock front bar was very limp. We upgraded the front bar and added a rear bar. The result was a smooth, comfortable ride that was stable with much less lean through the corners. He left the stock springs and shocks as they were and he was happy.

I appreciate the ride quality, comfort and the cornering stiffness of the Jaguar.

Cheers,
Mike