How to fix Taylor T5 standard mahogany G-string going out of tune a LOT?

[ZillaG]

I bought my T5 new with the standard Tusq nut and bridge saddle. It always stayed amazingly in tune. At one point, I experimented with putting 0.11-gauge Elixir acoustic guitar strings on it to get a different sound, but have now gone back to the default Elixir 0.11 electric guitar strings. I've noticed ever since the experiment, my G-string goes out of tune a lot and way more out-of-tune, compared to the other strings. It would seem like the acoustic string experiment have caused this this? If so how?

I've just now changed strings, and was careful this time to wrap the smaller 3-string (E, B & G) around my tuners more than I use to see if this alleviates the problem.

I want to consider getting a bone nut and saddle in the future. Will this help too?

[Radd]

If in fact the g string is behaving differently since the string change I think there are only 4 things that could effect only one string, tuner, nut, saddle and the string. 

I tend to be a simple thinker when dealing with things like this.  Odds are the tuner did not fail.  So, I would loosen the string and apply some nut/saddle lube, even graphite.  If no success change the G string even if it is new....Unless you did not stretch the g string enough when you first put it on and have not given it a few days to stabilize.

[Frayed Knot]

I agree; it's unlikely to be the tuning machine.  This will be proven over time if the tuning problem goes away as the string seats in the bridge and the slack on the tuning post is pulled out.  I can't imagine that it has anything to do w different strings.  Nut a possibility but nut lube should help that.  I have never used it. 

Next time you change the strings try doing these things:
1) with strings off, get a deep well nut driver that fits over the tuning post and check/snug up the machine to the headstock.  This only needs to be barely hand-tight. You will not need to do this every time. 
2) use a small screwdriver to check/tighten the tuning key screws but do not over-tighten. 
3) when you insert the string in to the bridge, I like to keep the retaining barrel parallel to the long axis of the saddle.  After inserting the pin w the concave side facing the headstock,  use a small pair of hognose pliers to tug firmly on the string at a 45 or so degree angle to the neck while holding the bridge pin in place w other hand.  This will firmly seat the string in the bridge.  You might feel a snap--good. 
4) now the hard part--the winding.  I have started using a head loupe with a 2.5 x magnifier and a bright LED.  (this has revolutionized string changing for me...). The largest string only needs 3 wraps and the smallest I like to use 6.  G string I'd say 4.  This does take some practice.  If there are too many wraps you can always go back and take it up a notch. Keep tension with one hand while turning winder w the other.  Once the winding is progressing, I'll use a plier to flatten the string against the post where it exits the hole for the wound strings..usually not necessary for the solid wire strings.  The windings should lie perfectly against one another without overlapping.  The string should enter the hole from the winding without a loop.  Once wound, bend the string w pliers or fingers in the opposite direction of the tuner travel then cut close to the post leaving 1/2 in or so. 

Once strung, I go through & stretch each string repeatedly at 12th fret.  Press the bridge pin firmly while stretching.  Stretch in the same direction you'd bend, not away from the fingerboard.  Retune, then some hard strumming and retuning.  I will also stretch the string w my fingers between the nut and the tuning post.  Don't use a tool or risk injuring the string.  You should be ready to gig.

This may not be your exact string changing procedure; my main advice is to get a solid procedure (taylor website or YouTube) and stick with it.  Tuning drift will occur with climate change, however, the drift should be about the same for each string. 

[ZillaG]

Thanks Radd and Frayed Not.

I've been changing strings on my guitars for a looooonnnnng time, and do have a procedure indeed, so that advice is spot on. When putting the string ball in the saddle, I just put enough string in, and then push it with the saddle pins. I do tug on it but only with my hands, so I'll try using pliers.

To ensure I have enough wraps I do this. I insert the string through the tuning pegs, with the tuning peg hole in-lined with string's slot on the nut. For wound strings, I grab it from the nut and pull it back so the point where I grabbed it from is 1-1/2 frets back; for unwound strings, I pull it back so the point where I grabbed it from is 2 frets back. This has given me at least 3 winds for the wound strings, and at least 6 winds for unwound strings, as Frayed Not recommended. This has always worked for me.

My tuners are fine, nut and small screws are snug.

I'll try to lube the nut and bridge, though I don't hear the string "popping" when tuning, which usually is the indication for a nut or saddle binding the string.

Thanks.