Hi,    My rear end differential is leaking oil & I would like to change the gasket on it.  Anyone know the part #?.   It has a tag on it with the #4148. I cannot find that anywhere.  I was also wondering about taking the plate off. I removed the drive shaft & the 10 nuts on the cover.  How is it "pryed" off after removing all the nuts off the bolts without damaging it?      Thanks, Mike