Greetings:

I have a 1988 740 wagon non-turbo 8 valve with an aw-70 a.t. it runs really well. However, I developed a gas leak this past summer via one of the lines connecting to the top of the fuel assembly unit (rusted out). This leakage caused some and or most of the protected paint/rubber undercoating to errode awawy from the rear diiferential and surrounding areas. I fixed this issue, now my rear differential can't seem to keep a gear oil contained. I just re-filled it (2 qts) last night, and most of it seems to have dripped/leaked out. I commute 99% hwy miles roughly 100 miles average each day. Now the rear end is just making a whining noise! I have placed a special order for a gasket via the dealer, however my fear is have i caused a significant damage to the gears? I have always used mibil 1 75w-90 and changed it very reguarly every 10,000 miles. Are there any other known areas for this fluid to leak out from, other than just the cover itself? Also how long of a job is it to remove and replace the gasket/cover? I beleive the cover has something like 10 bolts, some 12mm and others about 13mm or so. The car itself has 431,000 original miles on it, no rebuilds and or replacements. I runs excellent and burns no oil. Will a fresh refill of 80w-90 and or 75w-90 with a new gasket do the trick? I mean in terms of noise elimination? It has not begun to shudder just yet. But I just don't want to possibly replace the whole rear axle? I hear that these rear dana axles are very stout and bullet proof? What say you. Please all experiences and or suggestions are welcomed!!!

Thanks In advance!


Best Regards