2005 Highlander V6 AWD V6 3.3L questions

[NissanMaxima]

Hi all,
I just bought a used 2005 Highlander V6 3.3 L AWD with 125k miles. Impeccable carfax with regular maintenance except for differential and perhaps transmission oil changes. Two main questions for the community:

1. Carfax indicates transmission flush about 20 k miles ago. I think think this was done at a dealer and looks like the first time done. I would like to do the transmission oil again to be sure I know the fluid I have in there. I will go with genuine Toyota ATF but should I drop the pan and change the transmission filter too? Some YouTube videos encourage this, seemingly if only to clean off two magnets in the pan (one video showing a Highlander with quite a bit of metal fines) however then I saw these two videos below which then nearly convinced me it is not needed or even recommended unless you know something is amiss with the transmission. Emphasis is on the fact that transmissions are sealed systems (although the highlander does have a dipstick" and hence not subject to the same filtration requirements for engine oil. The second video was quite interesting when he cut open the filter which only showed small metal particles rather than sludge, etc. which was why the YouTuber emphasizes filter changes are not needed. I would probably do the job but there is always the risk of the gasket slipping during installation or some other mishap so looking to the community for input here.


2. The shop that did the prepurchase inspection for me indicated a "front and rear differential" and said the oil does need to be changed. Not surprising as the owners indicated this has never been done. I'm looking at the owners manual and it indicates a "Transfer" and a "Rear Differential". I assume by "Transfer" this is the transfer case that the shop called the front differential? Oil specs for both are SAE 90 for above 0 F and SAE 80W or 80W-90 for below 0F. I am in Colorado and although not the higher elevations here, it can definitely dip below 0F. Does this mean I should go for the 80W or 80W-90?

TIA to all for input!

 

[millerbl00]

Drop the trans pan and clean magnets. use 75w-90 in front and rear diff.

 

[Thermo1223]

Transmissions are not sealed, they have vents and suffer from wear and tear just like engines. If you can change the filter, do it.

 

[NissanMaxima]

Drop the trans pan and clean magnets. use 75w-90 in front and rear diff.

Thanks. Neither video mentioned the benefits of dropping the pan to clean the magnets. I wondered about that. For the oil, why go down to 75W when owners manual specifies 80W-90 for below OF? Extra protection in extreme cold? I'll see what Toyota has today.

 

[The Critic]

Different transmission, but...

Transmission Filter Change - waste of time?

My FIL drives a 2008 Toyota Camry V6 with the U660 transaxle. Transmission Fluid Exchange was performed at 60K and at 90K(ish) using 9-10 qts of Toyota ATF-WS. A few weeks ago, at 152K, I removed the transmission oil pan (for the first time) to replace the filter. This transmission uses a...

bobistheoilguy.com

 

[dkryan]

Nissan Maxima -

We owned a 2005 Highlander 3.3L for almost fifteen years and 167,000 miles.
Here’s what I did to get it that far:

Yes, the diffs need new gear lube. I initially changed them at 20k miles and the lube in the rear diff was black, noticeably more so than the front. I used Amsoil Severe Gear 75w-90 gear lube and I didn’t change it again until I had the timing belt, water pump, and idler pulleys changed at 100k miles using an Aisin kit.

In spite of “the book” recommendation for 80w-90 gear lube, any quality 75w-90 synthetic gear lube will be fine. It’s the “90” that’s providing the protection.

As for the tranny, I had an indy shop use a T-Tec machine and replaced all of the T-IV with Amsoil ATF. No, it wasn’t a “flush,” it’s simply a fluid exchange machine that avoids the cleaners and the high pressure to pump new fluid in.

I have seen several dealerships use a BG branded machine and a lot of pressure to add cleaner to the tranny followed by tranny fluid. I avoided those faster than I avoided T-IV.

I never had the transmission pan dropped nor have I ever changed the filter.

I know you posted in another thread re: oils. And a valve cover leak.

Ours also leaked at the front and I simply changed it out for an OEM one. It’s not going to get any better using an HM oil. Bite the bullet (and the invoice) and change it.

Check to ensure the timing belt was changed at 100k miles. If not, I recommend you get it serviced. Others may say they’ve gone 50-100k miles past the recommended mileage limit, but if yours has a problem, it’s your wallet, not theirs.

That engine, minus a turbo and/or direct injection, is easy on oil. Any off the shelf full synthetic 0/5w-30 will be fine.

Enjoy your “new” Highlander!

 

[NissanMaxima]

In spite of “the book” recommendation for 80w-90 gear lube, any quality 75w-90 synthetic gear lube will be fine. It’s the “90” that’s providing the protection.


I have seen several dealerships use a BG branded machine and a lot of pressure to add cleaner to the tranny followed by tranny fluid. I avoided those faster than I avoided T-IV.

I never had the transmission pan dropped nor have I ever changed the filter.

Thanks for the detailed dkryan. For the gear lube, any issues with sticking with the book recommendation for 80W-90? I assume I would at least want to go with the 80W-90 rather than the straight 90 for extra winter protection here in Colorado?

Any regarding the comment about the Toyota T-IV, are you saying that is not a quality ATF fluid? I'm partial to genuine Toyota fluids but if the Toyota T-IV is problematic, that might not be good. Can I switch to synthetic ATF if I choose?

Finally, for the transmission pan, any drawbacks to dropping it and changing out the filter? As I mentioned, after watching the videos, I realized neither of them mentioned the presence of magnets so I can imagine a scenario that where magnets do exist, they can become full of metal fines to the point they stop attracting them, and hence an argument could be made to drop the pan, clean the magnets and change the filter. If I do that, I'm not sure if I need to use RTV sealant or not. I'm thinking if the original didn't have it on, then not use any.

 

[BAJA_05]

I just changed out the rear Differential in my 08 Tundra in signature with 75W85 Redline GL5. Did a spill and fill on the 6spd automatic tranny using Idemitsu ATF Type TLS-LV WS and LubeGard Red. Tranny shifts like night and day since being done.

 

[dkryan]

Thanks for the detailed dkryan. For the gear lube, any issues with sticking with the book recommendation for 80W-90? I assume I would at least want to go with the 80W-90 rather than the straight 90 for extra winter protection here in Colorado?

Any regarding the comment about the Toyota T-IV, are you saying that is not a quality ATF fluid? I'm partial to genuine Toyota fluids but if the Toyota T-IV is problematic, that might not be good. Can I switch to synthetic ATF if I choose?

Finally, for the transmission pan, any drawbacks to dropping it and changing out the filter? As I mentioned, after watching the videos, I realized neither of them mentioned the presence of magnets so I can imagine a scenario that where magnets do exist, they can become full of metal fines to the point they stop attracting them, and hence an argument could be made to drop the pan, clean the magnets and change the filter. If I do that, I'm not sure if I need to use RTV sealant or not. I'm thinking if the original didn't have it on, then not use any.

There’s zero issues with using an 80w-90 synthetic gear lube in the diffs.

Regarding T-IV tranny fluid, I’m not saying it’s not a quality fluid. I am saying I thought I saw a UOA (probably more than one) on BITOG whereby the T-IV fluid looked “worn out” with less than 60k miles on it. It’s definitely not a lifetime fluid.

Granted, those UOAs have been a few years back, but personally, I would use Amsoil, Valvoline MaxLife ATF, or Idemitsu ATF, in that order. Especially if you’re only changing it every 75,000 miles or so.

If you’re simply performing a drain and fill, it will take a few of those to remove most of the original fluid.

And yes, you can switch to a synthetic ATF. No worries.

There’s no drawback to dropping the pan and cleaning it out, as long as it is re-installed correct, i.e., proper torque on the bolts.

It sounds like you might sleep better at night if the pan is dropped and the filter is changed, though I suspect you’ll find as many “shavings” on the magnetized rear diff drain plug as you will on the pan magnets.

Keep us updated on how it goes.

 

[GSCJR]

There’s zero issues with using an 80w-90 synthetic gear lube in the diffs.

I did the same in my 2003, 80w-90 is all I ever used in the diffs and transfer case. ATF was whatever I had on hand, even ATF+4 sometimes was used as a fill. I never dropped that pan, just regular drain and fills until it went into a shipping container in 2019.

 

[tbm5690]

Enjoy the oil changes on your 3MZ...it has a little "gutter" under the filter so when you spin it off you can very cleanly let the spill flow directly into a pan despite the fact that it's side mounted. One of the easiest oil changes I've had on any vehicle.

 

[michaelluscher]

Enjoy the oil changes on your 3MZ...it has a little "gutter" under the filter so when you spin it off you can very cleanly let the spill flow directly into a pan despite the fact that it's side mounted. One of the easiest oil changes I've had on any vehicle.

I'm in this scenario and I don't like it
No cap

I've gotten pretty good at it over 10 years, but vertical filters are less messy to swap

 

[NissanMaxima]

Hi all, I bought some Valvoline HP 80W-90 gear oil that is rated GL5 and GL4. Manual specified Hypoid gear oil GL-5 so I guess I'm good there. Next to the GL4 specification, it says for synchronized manual transmission to use one of the MT fluids (again, since this is a differential case, I'm ignoring this).

Here's the real question... it also says it does NOT have limited slip additives for applications calling for limited slip gear oils and then calls out Ford, Chrysler and GM with some numbers after each one (TSB?). I found a section of the factory service manual that says for rebuilding the rear differential, hypoid oil LSD should be used to coat the parts. So now I'm confused if my rear diff is the LSD variety and if I need a gear oil with LSD additives. I even checked the VIN on the toyota site and no mention of having LSD although I'm not sure if that is definitive or not.

 

[NissanMaxima]

So I didn't take note of how the crush washers on the fill and drain plug were oriented on the rear differential. The new ones have a rounded side and a flat side. The dealership where I got the new ones says flat side always to any pan and rounded side against backside of fill and drain plug, so flat side seals against pan. But wouldn't rounded side conform to hole in the differential hole making the opposite orientation the intuitive one? Internet searches seem to indicate arguments for both approaches.

 

[NissanMaxima]

Here is a photo of the crush gaskets my local Toyota dealership sold me. One on left is rounded side up and one on right by the fill plug is flat side up. They say these crush gaskets work for the transfer case, and rear differential, fill and drain plugs. Does it make sense to orient the flat side towards the differential housing etc. as they instructed me? I'm really confused now because on my way out of the parts department, I ran into someone there that used to be a technician (now a service writer) that concurred with what Parts told me because he said it is the same logic as a spark plug where the flat side of the crush washer of a spark plug mates to the engine cylinder. I just looked at a Denso spark plug I have here and it is not that way. The rounded side of the washer will mate to the cylinder head.

 

[CapitalTruck]

Changing filter on this tranny isnt hard.

 

[NissanMaxima]

Changing filter on this tranny isnt hard.

Thanks for the input! I'll probably leave that job to last, if I do it, but at least do a drain and refill. The car has a leaking valve cover gasket that is higher up on the list.

 

[CapitalTruck]

Thanks for the input! I'll probably leave that job to last, if I do it, but at least do a drain and refill. The car has a leaking valve cover gasket that is higher up on the list.

Hopefully its the front valve cover, Im telling you, the rear one was a pain. I would follow the other poster’s advice and get an OEM valve cover gasket. The Fel-Pro one was really hard to keep in place.

 

[NissanMaxima]

Thanks. I have to look a bit more with my inspection mirror but all indications are just the front is leaking. Even that's going to be a challenge based on YouTube videos. I will definitely get OEM. I have a great Toyota dealership in the area with a top-notch parts counter that has treated me well for over 20 years.

 

[NissanMaxima]

It sounds like you might sleep better at night if the pan is dropped and the filter is changed, though I suspect you’ll find as many “shavings” on the magnetized rear diff drain plug as you will on the pan magnets.

Keep us updated on how it goes.

Hi dkryan. The magnetized rear diff drain plug was indeed coated with sludge just like shown on YouTube videos. No large shavings or other however which was good news. I replaced it with conventional Valvoline 80W-90 per owner's manual recommendation. The fluid was pretty dark, being the first change, so will probably do it again in another 5k perhaps after it has had ample time to circulate. It wasn't that bad of a job. Probably the toughest part was snaking an extension to access the top fill plug with the recessed 10mm. I doused both the drain and fill plug liberally with PB Blaster an hour before I did the job and think that certainly helped. I also was sure that the 10mm tool was well-seated into the recess before attempting to break them loose. It was apparent the previous mechanic that checked the fluid for the previous owner did not take that precaution so got a new one from my friendly Toyota parts people for a mere $7.