WTF was that noise/shudder?

So I was driving down the road today and felt a shudder like the engine stalled for about half a second, then heard a rough "grrrr" noise and then everything went back to normal. Did that once and then a couple times later I felt MAYBE a hard shift into overdrive (kinda kicked a little).
2011 V6 TRD OR 4x4. 61k miles. Haven't flushed tranny yet. I know its due for tranny flush now. Think that might help?
Also, I haven't towed much or been to hard on the transmission.
Any suggestions or solutions would be greatly appreciated as I plan on keeping this beautiful truck for at least another 100k miles.

 

Were you cornering at the time ?

 

U-joints, perhaps.

 

Wow, that was quick!
U joints as in propeller shaft??

 

I grease the diveline zirks every oil change

 

Nope. Driving straight

 

There goes my theory

 

Take a good look at the u-joints in the propeller shaft especially the one at the rear diff. I'm sorry, how many miles?

 

OK. Will do

 

I took it for a drive earlier to see if I could reproduce said anomaly but no luck

 

At least rule out driveshaft ready to fall off and take it from there.

 

I'll go look right now

 

Does your serpentine belt squeak at all? If so, I'd start replacing the idler pulleys one by one.

 

No squeek

 

Maybe I found a problem. Standby...

 

That carrier bearing (I think that's what it is) has quite a bit of play. Is that normal?

 

That ain't normal. Again, look good and hard at the u-joints and think about them as you replace the center bearing! Congrats and good luck!

 

You can see the drive shaft actually sits a little low in there. I pushed on it and it actually looks ripped inside

 

Its got 61,000 miles

 

61k, my bad; now I see that.

Have a great night!