I have a 1987 raider with auto trans that will not upshift into O/D. The O/D on-off button lights the dash indicator but no up or down shift. Other than that, the trans works very well... good shift timing and very good shift feel. Trans engages in drive or reverse firmly and quickly.I have about 40 miles on rebuilt 2.6. Prior to that the truck was not licensed since 1998. Any ideas on whats up with O/D? Fluid is clean and nice cherry red... no discernable odor. Also tach is not working so I cannot watch for RPM variance.