My nephew just got stranded in his 2003 E39 525in a remote part of northern California. Trying to help him via phone. If the differential is blown will the rear wheels still move? Also, it looks like his BST went off as well - no accident - does that make sense? Really appreciate any help from the community
Hi hope you all worked it out - the differential is simply a set of gears, the case serves to keep it in an oil bath so it's lubricated enough to, presumably, keep the metal of the gears cool enough to not, presumably, get so hot as to deform or, maybe, melt down? So, if blown means its blown all its fluid out due to a leak or bad seals or some such, _and_ that became evident before something extreme (like lots of ugly loud crunchy metallic noise, for instance) presumably the gear function would continue turning the gears via the driveshaft and getting power to the rear wheels, at least for some period of time. If overheating is a consequence of no gear lubrication I don't know how long one could drive before overheating the diff gear or a problem developing into a degree of inoperability. Probably not long though, I wouldn't be surprised if it was one or two tenths of a mile. BST? Not sure what system that's an acronym for?
Thank you very much for your reply. It did all work out. I did have to tow the car from Mount Shasta in northern California to Los Angeles. I was able to find a used differential on eBay and after install cost was about $1200. Thanks again! Scott P.S. - BST stands for Battery Safety Terminal - it shuts off the battery
