transmission/diffs/transfer case service interval?

Hi guys, Im a little confused on the service interval. I tried researching but all I see is mixed things here and there. Some people say 100k km (62k miles) and some say around 45k km (28k miles)...
I have a 2016 4runner ltd. Currently I have 52k km (32k miles)
Dealer says it's due for Transmission, diffs, transfer case oil changes. I declined as I thought it was so low on mileage so I figured I'd do some research before giving the go ahead. I don't do any towing just city driving.

 

Your manual has all of the recommended intervals.

preference: 30k if any off-roading, regular city driving, etc. 60k if it’s a highway queen.

I’ll do my first service at 15k just to give everything clean fluids. It’s easy to do yourself. Drain and fill.

 

Probably is early personally I'd let them do it (or my garage) but I do things sooner than later anyway. Google your years owners manual and look it up there. I typically go by that and maybe move things in 25% earlier but again that's just me. You'll read on here people doing front and rear diff like the first 3-4,000 miles crazy in my opinion but whatever helps you sleep at night go for it...

 

When in doubt, follow the owners manual.

 

Mine (2018 SR5P 4x4) doesn't specify intervals for trans, transfer case, front and rear diffs unless you're driving in extreme conditions. Toyota intended them to be lifetime fluids under normal driving conditions unless there is some sort of breech in one of these systems.

Does that mean that I won't ever change these oils? No, I'm not comfortable with that, personally.

I think I'll probably change them all at 100k miles since I drive under normal conditions.

Some people will think that's crazy. I think it's crazy to change them as early as some people do around here.

On a side note, has anyone done an oil analysis on any of the fluid changes listed above? Curious to see the results.

 

Yes, the Toyota service schedule does not mention differential or transfer case fluid change at all, unless under special operating conditions: driving on dirt roads that strain gears, pulling a trailer. Transmission fluid also does not need change. I don't understand why a dirt road would significantly increase strain on differential or transfer case fluid. Nevertheless, because fluid technology was different in the past, many believe differentials, transfer, transmission fluids need to be changed frequently. There is a long history of changing engine oil at 3000 miles as well as differentials, etc. but that does not appear to be the case now, at least foR Toyota. The Toyota schedule says that frequent changes are not necessary. I'm stuck in old school thinking, so I'll probably change my rear diff, transfer case, and transmission at 70K, front diff at 100K. I off-road about 20%.

 

30k for diffs & transfer case.

60k for transmission.

5 years or 60k for engine coolant.

 

You're going to get different responses from anyone you ask. It starts with the recommendations from the people that build the parts. Then Toyota changes that to what they think is acceptable and works on their paperwork that they have to submit to the government and Toyota itself from a global perspective. For example if you call the people that designed and built the rear differential they May recommend something like only driving it very slow for the first 500 miles and never more than 10 to 15 minutes at a time before stopping turning it off and letting it cool down all the way before starting again. Then changing the break in fluid at 500 miles... Toyota's not going to put that in any of their manuals or tell you that in the service department... Same goes for the transfer case and transmission and so on. To keep it simple just follow the manual or if you want to get crazy with it call the people that build the parts

And to add another layer of f***ery the people that make the filters and fluids have even different recommendations LOL

 

When I traded in my old tundra from my 4Runner i was towing a 4,000 lb center console. I laughed and asked the service guy if this would hurt the break in he laughed too and said the important break-ins are all done at the factory

 

I’m going to change rear diff and tranny at 40k. Front and transfer case at 60k. I’m mostly highway miles.

 

Depends on how you drive. If you're off roading a lot fording streams and running mud/swamp whatever you should do at least the diffs after every adventure checking for water intrusion and the breathers for blockage. Four wheeling comes with a price. If not I would recommend following the severe service maintenance intervals fluid changes are cheap compared to repair costs. Money well spent certainly won't hurt. Even better if you can do it yourself.