I thought the XL-18 additive was now being discouraged because it might have long term harmful effects on the synchros. I would not mind trying it, the $23 is worth the experiment, but if it negatively affects the longevity of the synchros, then no way.
My transmission mostly shifts fine but that 1 -> 2 nibble is there most of the time, weirdly, particularly when turning left.??? Makes me wonder if the transmission torques out of line with the shifter a bit during a left turn.
Deysha can you confirm whether use of XL-18 is now thought to be harmful or not?
It is not harmful, guys. However, like any other additive if you add too much of it itíll change the viscosity and cause slippage/damage. You should always consult with your service manager/tech at your dealer before adding anything to your vehicle.