When is It’s time to change rear and front differential plus transfer case oil

Came to the dealer ship and Dave recommended rear and Front differential plus transfer case oil change when is it time to change it?

 

I think officially Toyota just says check it every 30k. Unless you are doing serious off roading or have a lot of miles, you shouldn’t need to change it already on a 2018.

 

Dave is just looking to boost his numbers. Depending on how often and hard you use 4WD, the transfer case should be good for at least 75-100k. The fluid is ridiculously expensive (if the dealer is charging less than $300 they aren't using the right oil) so there is no reason to change it early.

I changed the oil in my diffs at 35k. The rear was dark and had a fair amount of debris on the magnet. The front looked new. That said, unless the oil gets contaminated it should last a long time. I changed mine out because I'm planning to keep the truck another 10-15 years and its only about $60 to do it yourself.

How many miles are on the truck and how do you use it? Off-roading? towing? highway?

 

Just use Royal Purple Synchromax for the transfer case, it is significantly cheaper than the OEM fluid and is compatible.

 

The answer is right there in the owners manual that came with your truck

 

I'm pretty sure the manual only suggests these fluids be changed under "special operating conditions" so it is somewhat vague.

 

Here is the sticky with all manual and info you may ever need- https://www.tundras.com/threads/tundra-maintenance-guide.315/

 

That's true. I was just letting the OP know where to find the answer.

30k miles for special conditions.

 

I still love your user everytime I see it.

I realize I'm completely off topic. Sorry.

 

I did my rear and front differential plus transfer case oil at 25,000...mainly because I was bored with now having a truck that doesn't have something broke and defective every other week like my 2010 GMC Sierra did before this.
Used Ravenol and Red Line for replacement fluids.
Rear diff also, like @AZBoatHauler, had debris on the magnet. Other fluids looked great, but still glad I did it. Easy job.
I am a very light-duty owner: low mileage no towing, no rock climbing... probably won't change it again until 60,000 or 5 years.

 

Bought my truck used at 42k, currently have 56k on it now and I’m slow rolling this service. Dealer wanted to charge $440 for their “4x4 service.” I said thanks but no thanks. So far I’ve got the rear diff done. Fluid looked dark and there were a decent amount of fine shavings on the plug, nothing out of the ordinary. I plan to do mine every 30k.