i put 75w-140 redline in my rear diff. it calls for 75w-90 will this be ok? all feedback appreceated.

 

75w140 basically a shockproof lub used in racing and heavy duty rear use. Should be perfectly ok.

I'd consider using the recommended weights for street use the next time you change your rear oil. I don't know why, but just for the hell of it.JMHO