Rear differential fluid change interval

I have a RWD 3rd gen. I ended up taking my truck to Valvoline for an oil change and they told me the rear diff fluid needs to be changed every 15k. I haven't towed anything for a couple of years, was curious if this is overkill?

 

I do every 30K miles. That is considered overkill.

 

I do mine every 50k and the gear oil looked new. If i was harder on my truck, I would probably lower the interval to 30k. That service center is more interested in flushing your wallet than your diff. JMO.

 

30 k is more than adequate

 

I did mine at 40K miles. Bookmark the Maintenance Map. Lots of great info in post #1.

https://www.tacomaworld.com/threads/3rd-gen-maintenance-maps-get-300k-miles.789809/

 

Toyota maintenance manual says nothing about rear differential oil changes except for "Special Operating Conditions" (offroad use, heavy towing, etc.) then it's every 15K miles. If you're not offroad much or aren't towing more than very occasionally, a 60K-mile rear diff oil change should be plenty.

 

Do the first early, and then every 30-60k depending on use

 

Did my diff fluids and TC at 25k. Rear was milky grey with no chunks the others were pristine. Currently at 65k and will do them again at 100k.

 

I just did my fluids and U-Joint greasing over the weekend on my used 2019 TRD Pro. I've had the truck for about 5,000 miles with a total of 40,750 on the clock. Motor oil and Front Diff fluids all looked par for course. The 2 U-Joint zerks took in quite a bit of grease each (pretty sure that's never been done on this truck before), but the real shocker was the amount of diff fluid that came out the rear. Only about .5 to .75 of a qt. came out of the rear diff as apposed to the 4.2q that I was expecting. No real metal build up on the drain magnet but still, don't love that.

As there were no obvious signs of leaks anywhere around the rear end I'm at a loss as to how almost a gallon of fluid could disappear like that.... something to keep an eye on for sure. So yeah, I'll likely be checking my rear diff ever 5K miles or so for the foreseeable future.

Gotta love the unknowns of used vehicles..

 

I went to Valvoline for my 20,000 mile service, and was told by the tech it is recommended to have both diffs and transfer done, but they didn't have the right transfer lube and recommended I go to the dealer.
I called the local dealer to schedule the tranfer lube change, he asked are you having trouble? I answered no, and he said then no need to have it done until 60,000.
Lesson learned, check the manual, before approving additional services.
Oh, and I wanted the tires rotated, Valvoline said the truck weighs too much for their lift.

 

Only thing surprising here is that they didn't just fill it with 10W-40, slap you on the back and call it a day...