New to me 07 TRD Sport - Changed rear diff fluid to syn then back to dino, rear end vibration

I just got my first pickup truck, new to me 07 TRD Sport 188k.

In my attempt to take care of it I changed rear diff fluid with Valvoline synpower 75w-90 that says it had LSD additive already in it. Didn't think I needed to add any extra LSD additive so I didn't.
Drove it for around 100mi until I noticed I was getting some vibrations around 25mph vibrations reversing while turning. Nothing audible, just feeling. Rear end never locked up or made any alarming clanks or bangs.

Further research (ie reading 50+ pages form the thread: https://www.tacomaworld.com/threads/changing-differential-fluid-a-step-by-step-how-to.24545/)
indicated I should be using dino oil in rear mechanical LSD instead of syn so I drained and filled again with NAPA GL-5 80W-90 since it was on sale for $5.49/qt. Per the instructions on the back I added the whole 7oz tube of Trans-X after adding about 1.5qts of dino. Filled the rest of the way and drove to a parking lot and did 8-10 figure-8s to mix it all up.

Driving to work this morning I am still noticing a little bit of vibration from the rear at low speed (straight or turning). Is this likely indicative of damage I did or possibly didn't get enough of the old oil out? Should I drain and fill again? Thanks!

 

It’s something else.

 

Any pointers where to look next? It started pretty much after changing the diff fluid?

 

Center bearing. Get under there and push it up. There shouldn’t be too much play.

 

Thanks! I'll take a look... do you guesstimate it's coincidence that it would be noticed right after changing diff oil? And/or think there's any chance I did damage running the syn oil for a half a tank of gas?

 

Hopefully it’s just the cb.

 

Probably something else.
I ran Dino 75w90 with LSD additive stock.

Now have TrueTrac with Lucas sae 75w140. Never vibrated.

many other things on these trucks when worn out can start to vibrate.

 

Probably not wrong considering it's creeping up on 200k miles. Probably also not worth freaking out about..it's a taco, it's fine lol. It's only at it's mid-life so they say! Key is to balance preventative maintenance with reliability. It's bone stock so no lifts and suspension to worry about. Leafs look fine despite what people say about them giving out.