The serial number isn't a whole lot of help. The first number is the year in a decade, the second and third number is the month, the next 5 numbers are the number off the line from Aisin. So for yours: 6- (1986 or 1996) 10- October 05245- 5245th transmission off the line from Aisin that month. However the 5246th transmission may have been a 2wd transmission, and the 5244th transmission may have been a Jeep transmission. There isn't like a span of numbers that were all R150's and a span that were all W56's or anything.