I finally saw a Jag IRS setup

[G.R.]

There have to be hundreds, if not thousands, of street rods/hot rods and Cobra replicas running the Jag rearend.... let alone in original Jags since "62 or so.
Sure some have failed...due to maintence, negligence or fatigue .... or ignorance/stupidity on the owners part.

It must be he!! to be an engineer (no offense meant if you are one)
If I worried about every little niggly thing about any car I drive I would never drive it, be it the replica or the daily driver.

[double ugly]

I don't think I would have ever crawled into a fighter if breakage was on my mind. Paranoia sets in much later in life.
John

[Tom Wells]

Yetiman,

The car simply rolled to a stop and would not move on it's own power (which kind of surprised me with the limited slip).

Actually this wouldn't surprise me.

When the axle lets go, my bet would be that the top of the tire gets up against the body.

In my car if the tire leans in toward the center, the top of the tire would quickly come into contact with the seat bucket. This would most likely have two effects: The tire would act as though its brake was applied, and second, it would not lean any further. In my car the angle of lean would be very slight since the tire occasionally contacts the body at that point under full deflection... Other car bodies may be different.

That axle failure is not unusual on Jags - probably more common than the u-joint failure. Glad you only had a "Maalox moment" and did not accrue any personal damage CWI http://www.cwiinc.com/index.html sells HD parts for those axles that help a lot.

BTW, Mustang-type IRSs suffer from similar weaknesses, so drag racers tend to go for the live axles instead, and even those occasionally break. A stick shift with repetitive very hard launches at a drag strip using slicks is not a good application for an IRS.

Regards,

Tom

[rdorman]

If they break, what you say is true. Every one knows what you have pointed out, not an 'ideal' design. Any component, no matter how well designed, can fail. If you are that uncomfortable with Jag rear ends, simply don't get a car with one. To answer your orignal question, "Yes, it is common knowledge that it is not an ideal design" However, it is well executed. Kind of reminds me of the Porsche 911. One of the more interesting ways to describe the basic layout of the 911 I have heard is "A bad idea carried out to perfection" Who ever thought that hanging the motor out behind the rear wheels on a sports car must of been on crack But damn do I love them