>Metal on metal is not the way to lock
>a diff - it's lunacy. People compensate for the inadequate
>locking grip by using even heavier springs, which just further
>stresses the unit. I don't care if it works or not - there's
>better designed options out there for similar if not better
>pricing. Alternatives that include properly rated springs and
>the addition of a clutch materal to hold on the planetaries,
>which have been machined flat to take the material.


I couldn't disagree more. I have researched this to extreme measures. Have you ever opened up the case on yout NV Trans? Metal on metal is how your trans operates, thats what Manual trans fluid is for. I designed this SID with input from New Venture and got alot of positive response from them. My units use steel similiar to the same steel that your trans components are made of. As far as using heavier springs placing stress on the unit goes....this is how the unit works. The more "stress" you place on the unit the less slip you will incur. That is the entire technology behind the unit. As far as these type of units "destroying your trans", i have customers running high boost levels in several different vehicles with zero failuers.....