Bmach

I was getting ghost shifting when under a load. I adjusted the barrel adjuster, the ghost shifting went away. The RD will now not shift into the 34t, the L limit is not touching and I can move the RD by hand and it will shift into the 34t If I move the barrel adjuster and get back to ghost shiftING it will now shift into the 34t Any ideas.

base2 

You adjusted the barrel adjustor to lower the cable tension. The jockey wheel is now aligned with the second largest cog.
Turn it the other way (out/counter clockwise/left) to increase the cable tension to pull it up to the big cog.

I find it's best to start with the smallest cog & hit the shifter to the second smallest cog. Then turn the barrel adjustor until a shift happens. That usually gets you close. Then run through all the gears one at a time. At the top, releasing a shifter click to the second biggest cog & turn the adjustor until a shift happens.

Shift to the other front chain ring & repeat.

Nominal is usually when the barrel adjustor is about half way between. When it runs silent and hits all cogs accuratly in either ring, stop. Your done.

There is nothing wrong with getting down low behind the bike & eyeballing how the upper jockey wheel lines up with a cog & seeing which way you need to adjust the barrel adjustor.

How's your B-screw? 40 tooth is out of spec for GRX, BTW.

Bmach

Thanks for the reply I will give it a try. And why I said 40 I have no idea it is a 34. Only off by 6.

cxwrench

There are untold dozens and dozens of great videos on YT about adjusting derailleurs. I suggest watching a few of them, it's always easier to learn how to do something when you can watch someone do it properly.

Bmach

I did but base2’s post was perfect. It took me all of 45 seconds to get it right.

thanks base2