MTfluid for grinding/hard shifts
 

I have some trouble shifting into 5th as it seems others have as well at times, 5th gear at 60+ welcomes me with a whirring grind noise and wont go in right away, it eases some and doesn't make a noise at times if I hold it against the gear for a second before it slips itself in. I was thinking of doing yet another fluid change. The first time I didn't notice any flakes but also I didnt notice to see if there were a magnet. I heard Redline Shockproof was a great solution but I'm having troubling finding some to buy.
(another may-be related issue) going from second to third at times brings a loss of power where the engine continues to fall or idle in gear spinning at 1800-3000 wherever I shift and doesn't give any negative feedback but doesn't have power while I assume the clutch is still engaging? No problem when gunning it though.

I live in CA where it's gonna be getting a lot hotter in the coming days averages 110F usual. I just but 0w-20 in 5.4L, I wouldve went higher buuut I need to pass a smog test. I'll do the clutch, pressure plate(i assume too), and flywheel, do the bearings and would anyone knowledgeable enough suggest doing pilot bearing or clutch forks too? I always wanted to do short shifter even if it doesn't improve it That much but maybe it could help?

just reminded that I may be able to go under the clutch fork(i believe its called) and put silver silicone grease to lube it from squeaking if it does as I press the pedal in.

Any 2 cents is well transformed.

There is a bit to unpack here. So your main issue is changing into 5th at 60+ mph? are you up shifting or down shifting when you have the issue? Did you end up replacing your clutch already? If so what brand are you using? What brand of gearbox oil are you using now?

Redline shock proof is not recommended for our gearbox. It will be too slippery for your synchros and make your problems worse. Redline MT90 has worked well for me.

If you haven't put a decent clutch in yet do that before worrying about fluids. You are best off doing one thing at a time when problem solving issues.

Get your gearbox working well before you worry about a shortshifter.

I don't know what your engine oil being 0w-20 has to do with any shifting issues.

Your loss of power going from 2nd to 3rd wont be gearbox related. More likely tune or bad choice of bolt on parts.

Yes silicone grease can help with squeaking.