TrueTrac (Detroit) was bought out by Eaton a little over 2 years ago. You'd probably have to contact them.
Just looking at the online owners manual, it looks like 1 year from date of DELIVERY, or 100,000 miles, whichever occurs first.
http://www.eaton.com/EatonCom/ProductsServices/PerformanceProducts/Products/Differentials/NoSPIN/index.htm?ssSourceNodeId=5334&ssSourceSiteId=EatonCom
Bob
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