I’ve got a 2015 SR5P with 114k miles and I don’t think the diff fluid has ever been changed. I’m planning to use Redline 50604 MT-LV 70W/75W GL-4 for the transfer case since that seems to be the right one. But is Mobil 1 75W90 okay to use in the front and rear diffs? I know this has been asked a lot but I want to double-check before I go ahead and order it. Also open to other non-OEM brands you all like using.
@Christie
I used the Valvoline squeeze bags — huge respect to whoever came up with those. Made it way easier to fill both diffs and the transfer case.
@Christie
Gotta say, your rig looks super clean.
@Christie
I usually go with Mobil 1 — it’s solid and I think that’s what the dealer near me uses too. I ran Valvoline in my old 4th gen and it was totally fine. That bag setup does look like it would make the job easier. And yeah, Valvoline is usually cheaper too.
@Vince
Valvoline’s worked great in my tow rigs for years. The bags are a game changer — skip the hassle and just grab those.
@Christie
You can also grab a pump/hose kit off Amazon for like 10-15 bucks: Amazon.com: Lower Unit Gear Oil Pump for Standard Quart Bottle(28mm Caps), Fit Most Marine Boat Outboard Motors, Come with 3 Generic Adapters Plugs Kit : Sports & Outdoors
Maxwell said:
@Christie
You can also grab a pump/hose kit off Amazon for like 10-15 bucks: Amazon.com: Lower Unit Gear Oil Pump for Standard Quart Bottle(28mm Caps), Fit Most Marine Boat Outboard Motors, Come with 3 Generic Adapters Plugs Kit : Sports & Outdoors
Those pumps are such a pain. My arm always gets tired, and it’s worse if the straw doesn’t reach the bottom of the bottle. The squeeze bags are a lifesaver.
Trust me, the squeeze bags make filling the front diff and t-case way easier than using a pump.
Milan said:
Trust me, the squeeze bags make filling the front diff and t-case way easier than using a pump.
I’d go for them but Redline doesn’t make bags 
I’ve got a Slippery Pete pump so hopefully that helps. Might just switch to Valvoline if it’s easier.
@Vince
Amsoil makes squeeze bags too and they test really well — but yeah, it’s not cheap.
Yep, I’ve always used 75w-90 in my 4Runner — way easier to find than 75w-80. I’ve done 3 fluid changes over 12 years/80k miles and it’s been running great.
Only tip: get the bag version, they’re way easier to handle under the truck.
@Ozzy
Probably should’ve gone with the bags… but I’m loyal to Mobil 1 
Valvoline Flex Bags are awesome. Been using Valvoline for years and never had any problems.
That’s what I used. No issues. I did mine at 160k and I don’t think it had ever been changed. Still shifts smooth at 165k and the old fluid didn’t look bad either.
Darcy said:
That’s what I used. No issues. I did mine at 160k and I don’t think it had ever been changed. Still shifts smooth at 165k and the old fluid didn’t look bad either.
Same here — mine shifts super smooth but I want to do it just as preventive maintenance. Seems like most 4Runner owners (aka soccer moms) don’t even think about this stuff.
@Vince
Make sure you do your spark plugs too — you’ll notice a difference.
Maxwell said:
@Vince
Make sure you do your spark plugs too — you’ll notice a difference.
Did those about 4k miles ago. Didn’t really feel much different, but the engine is a bit quieter and MPG is slightly better. Probably because the old ones weren’t in bad shape.
Same here — I used that weight but went with the Valvoline squeeze bags.
Amsoil squeeze bags worked great for me. Just did my front and rear diffs today.