The source of heat seems to be the driveshaft hub where the u/j is and has been very hot and most discoloured. Would be interested to see the joint when the shaft is removed and the gaiter. The bearing seat is the lightest so maybe the bearing was a casualty of the heat source.
One thing I would check is that the driveshaft mounting surface for the bearing is either shorter then the thickness of the inner race or that the hub has enough relief on it such that the hub does actually clamp the bearing instead of either the nut bottoming on the thread or the hub bottoming on the bearing mounting surface.
The discolouration on the shaft looks more like lubricant varnish due to the bearing spinning, as opposed to the steel heating up enough to get into the heat treatment range. In the slight possibility the discolouration is due to oxidation in the heat treatment range, the shaft and hub likely would need replacement due to change in the steel properties.
The source of heat seems to be the driveshaft hub where the u/j is and has been very hot and most discoloured. Would be interested to see the joint when the shaft is removed and the gaiter. The bearing seat is the lightest so maybe the bearing was a casualty of the heat source.
2019 310S 1.6 Sigma
One thing I would check is that the driveshaft mounting surface for the bearing is either shorter then the thickness of the inner race or that the hub has enough relief on it such that the hub does actually clamp the bearing instead of either the nut bottoming on the thread or the hub bottoming on the bearing mounting surface.
The discolouration on the shaft looks more like lubricant varnish due to the bearing spinning, as opposed to the steel heating up enough to get into the heat treatment range. In the slight possibility the discolouration is due to oxidation in the heat treatment range, the shaft and hub likely would need replacement due to change in the steel properties.
James