Differentials and Transfer Case-can I use synthetic?

[Mhayden37]

I recently purchased my 05 4Runner with 100K on it. Previous Owner bought it as a CPO vehicle and I am assuming (maybe a big assumption here) that the dealer changed the differentials and transfer case at that time (60K miles). Can I just go with synthetic oil at this time? No flush, just drain and fill?
THANKS!:help:

 

[4gin007]

As long as its gear oil. I use mobile 1 synthetic gear oil 75w 90.

 

[BlackWorksInc]

As long as you're using the specified fluid viscocity and rating, synthetic or dino works fine. I run Amsoil's heavy duty synthetic gear oil in all 3 differntials.

 

[montijo505]

Sorry to thread jack but.... I swapped both my cv axles last week and planned to drain and fill front diff. Lost about a quarter to half of a quart of oil, which was grimy!! Managed to strip my diff drain plug so I couldn't drain it. I ended up just topping it off with 80w90 GL5 I had available. Will it be ok for a while or do I need to drain/fill ASAP? I really need to know cuz I have a wheeling trip hopefully in a week, thanks in advance!!

 

[4gin007]

Your wheeling trip should be fine as long as the correct amount of fluid is in it. But asap after that id fix the drain plug and drain and refill it.

 

[JEL]

I hate the front plugs, I had the same problem and it was a royal PITA to get off (ended up welding a nut on). You can get it warmed up by driving around in 4hi and then siphon out as much as you can with a small pump you can probably pick up for $5, then top it off with new, that should get about 3/4 of the old stuff out. That'll be fine for another 30k IMO.

 

[montijo505]

Your wheeling trip should be fine as long as the correct amount of fluid is in it. But asap after that id fix the drain plug and drain and refill it.

Thanks man, I'm just gonna have someone weld a bolt to it and probably to the new one too!