I have 2015 Highlander AWD and only put about 5K miles per year. Around 40K miles on it now. I do change engine oil once a year when doing inspection but I was wondering when do I need to change oil in transmission, differential and in the gearbox. Should I wait until 60K or change it now? Is there any risk if I wait until 60K to change oil in transmission and gearbox? Does transmission and gearbox oil gets bad with age or from millage?
Should I wait until 60K or change it now?
No, change it now. Scotty says, "Engines are expensive and oil is cheap". Same is also true about AWD components.
If your transmission hasn't been serviced, have that done too.
The differential and transfer case fluids in most AWD systems should be changed around every 30k (see Scotty’s recent video). The transmission fluid interval has been discussed here ad nauseum.
