Never change your differential fluid?!!

Looking over my shoulder slowly with a can of brake clean.

 

At that milage and years other than the usual engine oil/filter changes you need to change out every fluid... brake, trans, power steering, radiator, front/rear diffs, trans case, grease driveline, etc. Should have been done long ago. Read your owners manual about what's needed at the service intervals.
edit... since you have a 2wd skip the front diff/trans case.

 

Supposed to be every 30,000 miles

 

That would’ve been nice to know with your opening questions. Maybe something like this for example.

I bought my truck with 174k, it now has 184k, I’m not sure if the transmission or differentials have been serviced but the fluid look clean, do you think it would be a good idea to service now and then get on a regular maintenance cycle?

this would’ve been very helpful

 

Everyone else seems to be adding to this so why not me lol.

I bought my 2010 auto TRD OR little over 2 years ago from a buddy I went to college with. He had it since 40K, Had 289K on it when I bought it.

He did regular oil changes but had never changed the diff, Xcase, trans or any other fluids. The truck has zero issues now with 310K, of course I have changed most of the fluids but I have no intentions of changing the trans due to the high mileage.

skip to 5 minutes on the below video for the reason as to why I don't plan on changing.

https://www.youtube.com/watch?v=jJr30r6RRgw&t=925s

 

Just changed transfer case oil @ 103k, looked perfectly fine.
Used the liquid gold oil,I got it way back in 2016, 35.00 can.
Unless your wheeling often I don't buy into every 30k change.