stuck in overdrive

["Bluechipracing" <bluechipracing@snet.net>]

Occasionally my BN2 gets stuck in overdrive (physically stuck, not an
electrical problem), and won't come out untill everything cools down, or I
bang on the brake ring with the KO hammer.  I believe its the cone clutch
sticking to the brake ring, but I'm not absolutely sure of this.  When it
happens, I can't back up.
I use SAE30 non detergent oil in the gearbox.  Do you suppose one of the
specialty transmission oils like Red Line MT-90 would cure this situation?

Jim Smith