My uncle just informed me that my trans is not shifting into third (200,000 btw). So going cheap first, i was wondering if I could change fluid and filter. And he also mentioned that it could be a solinoid or a govenor whichever one the trans is controlled by?

First yes stop all driving change you fluid filter and pan gasket...and the ''govenor'' is controlled via your computer IIRC all it does is limit your speed..It could be the 2-3 solenoid..But first and foremost change that filter n fluid

It was going 50 just not and only read 1500rpm, i feel it shift a little bit but I can still feel the lag if i let off from it.

Your probably feeling it shift but the tc is not locking unlockin correctly......Any codes

No codes, I was travelling at 50 and shifted down to third and i felt and saw it shift down

Okay did it stay there...return to 4th at all if so how long did it take

Yes, it goes into od at about 50ish. Its light but i do feel it shift into third and fourth.

Since most of our driving is in 3rd gear, those are the clutches that wear the most. It'* possible they are simply done at 200K.

Ahh no don't say that, I dont want to pull the engine to replace the clutches... if thats how i do it.

I'll change my fluid and filter first once I can afford new fluid and We'll see where that takes me