Jaguar Racing has revealed that Mark Webber's problems at the Japanese Grand Prix, were caused by a loose chassis fixing inside the cockpit, which was to blame for the Aussie's discomfort, after temperatures rapidly rose.

Mark Gillan, head of vehicle performance at Jaguar, explained they have now redesigned this 'feature' to stop a reoccurrence this weekend at the Brazilian Grand Prix, the final race on the 2004 schedule.

"In Japan it was evident that the pace of the car was impressive and that made the failure which led to Mark's retirement all the more disappointing," he said.

"After the race it became apparent that an internal cockpit chassis fixing had come loose, which led to hot air from the engine entering the cockpit and heating Mark's seat to a point which became unbearable for him to continue.

"We have re-designed this feature to prevent a repeat of this failure and fortunately Mark is fine for the Brazilian race weekend."

Speaking after pulling out of the Suzuka race two weeks ago, Webber revealed that conditions were quite simply unbearable.

"It was on lap seven that I noticed that the cockpit was becoming increasingly hot and, in particular, my right-hand side," he revealed, "I pitted as planned on lap eleven and the team tried to cool me down by pouring water over me to solve the problem, but we could not find the cause for the heat, so I carried on in the hope that it would cool down - or at least remain static.

"It didn't work, though, and the heat soon became excruciatingly hot. I had no option but to retire. You need to be completed focused on the race and, when the temperature is so high that you are being physically affected and thus distracted, then you need to take the decision to stop."