Has anyone had any bad experiences with Castrol MTX gear oil been used in the tranny and primary? 

 Thanks for the advice, I think I will Just use Mobil 1 in all three holes.

cheers

Redline Shockproof in the tranny, Harley Primary oil, (in the primary), and Mobil 1 CAR OIL yes CAR OIL 20 w 50 fully synthetic in the engine.
Mobil told me it was identical to Mobil 1 V Twin, and costs half....

https://www.mobiloil.com/USA-English/MotorOil/Car_Care/AskMobil/Mobil_1_15W-50_in_Harley-Davidsons.aspx

i use and recommend Nulon Smooth shift 75/90 in HD trannnys, smooths them right out . i have got plenty of good comments from owners after using it in their bikes. its priced well and can be got from Supacheap. dont use it in your primary though, it contains a friction modifier.

just serviced mine and run mobil v-twin in the engine and box and valvoline type F  ATF  in the primary.had harley oil in the box before but it definitely changes smoother with the mobil v-twin oil.