Those looking for a locking alternative may like to read this. The peloquin diff is an interesting option. My Syncro came without any locking differentials I recently did a costing exercise on purchasing all the relevant parts need to convert one diff. To purchase the complete list of parts for one differential - $2171.00 AU in today's conversion - US to AU dollars. This price includes freight to AU. To install these parts requires labour - plus The front diff requires machining the blank port to install the locking lever. Allow $200.00 To fit the same to the rear diff - which - in my case doesn't include a cast port for the locking actuator - purchase a secondhand case -at around $800 AU Plus machining the same case to suit the locker - allow $200 AU Plus labour to assemble the complete diff. Allow $480.00 AU approx Front differential Parts $2171.00 Labour $480.00 Machining $ 200.00 Totals $2851 rear differential Parts $2171.00 Labour $480.00 Machining $ 200.00 Diff case with port $800 Totals $3651 Add to the above a Vacuum circuit and controls - allow minimum $500 Or Buy One Peloquin differential to suit the Syncro case - at $1654.00 AU in today's conversion - US to AU dollars. Plus Freight -allow $150 AU =$1800.00 AU Plus labour to install in either front or rear differential Buy two Peloquin Diffs for a total of $3600.00 Plus labour to install Hmmm .. ???