Weird! '92 5-speed linkage just got super-easy to shift

[SchlockRod]

What's up with this?
When I bought this car, with 165k on it, it was very balky and vague to shift, particularly going up or down into third.
I decided to change the trans fluid. I have seen many posts of people willy-nilly using Pennzoil Synchromesh, Mobil 1 engine oil, etc.
I stuck with the recommended 75W90 GL-4 lube (actually there was a discrepancy between the owner's manual and the maintenance schedule - one said GL-4 and one said GL-5 - a talk with Amsoil tech service convinced me it should be GL-4). I went with Amsoil synthetic.
There was a 100% improvement. My fears about needing a transmission went away completely. I've put 30,000 miles on it with the Amsoil. There was still some balkiness; by that I mean that you could feel the synchros working most of the time, with a notchy feel before sliding into gear. Sometimes if things were just right it would slide smoothly in, but that was the exception. But actual difficulty finding third or fourth was a thing of the past.
The car now has 198,000 on it. Now just the other day, after driving 25 minutes across town on the freeway, in driving rain with heavy slush on the road, doing about 70-75 mph, I exited to find that the shifting has suddenly undergone what I can only describe as another 200% improvement!
Going from gear to gear is absolutely effortless! The notchiness of the synchros working is nonexistent! Every gear change feels as though the speeds of the gears are perfectly matched! I am moving the shifter from gear to gear with a very gentle slide, using only my thumb and index finger!
After three days, it remains the same! I am not exaggerating when I say it is amazing!
Can anyone explain this? Is it possible water found its way into the tranny, affecting the properties of the fluid, and that this is actually a bad thing?

[way]

Perhaps the slush is a clue? I presume if you're anything like me, that you could observe the speedometer jump up and down as the wheels occasionally lost traction? Maybe that spinning loosened something up, maybe knocked some sludge out somewhere? It might be a good idea to change the fluid now to get rid of it?

I have recently regained first gear after having lost it for months. I presume it's only temporary because I suspect it's just because the synchro has worked its way back into a position where I can shift again. The reason I mention this is that perhaps something similar was happening with you except that it was caused by sludge. I'm already double clutching to get into first so it's probably not not for much longer.

Just a thought though. I know Amsoil is kind of expensive.

[leonbentz]

It's possible your shift linkage needs to be cleaned up and relubed. I had an old Subaru GL that was like this. I pulled the dust boot from the console and cleaned up the shift linkage and relubed it. What a difference that made.

Probably what happened to you was, the water and slush got up into your linkage and loosened it up a bit. My window regulators are pretty stiff most of the time, but sometimes when it rains hard enough, they loosen up and my windows work fine.