ahh I thought it was a 188 case, must a mixed that up..it's the diff out a my car, ratio wise was told it was a 3.65 lsd from a e30 built into that case. 25% been the standard BMW lock .I've broke open diffs but this one has been faultless for me. this could be down to been always cautious, never drifting in the dry, no shock to the drivetrain ie no full bore clutch kick transitions..I guess it was always on my mind that if I broke it that was that..spose oil changed with 75/140 and a full rebuild helps alot ratio is brilliant, leaves other is's no problem in a straight, tops out on the limit in 5th at an indicated 140mph so maybe a true 130 and sits at 100km/hr in top at 3050rpm I'm nearly sure