I could see full synthetics leaking out of seals. As old seals may not handle the thinner oil. On most of the drivetrain not and issue its rust proofing in the salt belt. ;)
Except, in the rear diff as we have drum brakes that can be soaked in gear grease.
Sent from my SM-J337V using Tapatalk
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7 3rd gens listed in the build thread (2 are parts mobiles)
Build Thread:
https://www.toyota-4runner.org/3rd-g...os-builds.html
Brillo's Bucket Fluid Ex changer:
https://www.toyota-4runner.org/3rd-g...ml#post3358086
Sparks Plugs Wire and Coil Information:
https://www.toyota-4runner.org/3rd-g...on-5vz-fe.html