When to change differential oil in 2010 highlander

[Drew1977]

Hi all,

I purchased a certified pre-owned 2010 highlander in December with 40K miles on it. I am approaching 45K and am not sure if the differential and transfer case oils have ever been changed. I don't fall into the towing/severe service category for which toyota specifies a 30K mile replacement. They don't really specify for "regular" use.

When should I consider changing these. I would prefer to push it out to 50K and service the transmission at the same time. Any thoughts?

 

[Kuato]

50k sounds good to me. You'll get lots of answers from "should have already" to "never". What will let you sleep at night?

 

[sicko]

Originally Posted By: Kuato
50k sounds good to me. You'll get lots of answers from "should have already" to "never". What will let you sleep at night?



This.

Keep in mind that although you don't fall into the towing/severe use category, you don't know how the original owner used the vehicle.

Regardless of how the vehicle is used, I prefer to do the first change earlier with the severe use schedule to get the wear metals from manufacturing out. But considering that most people I know never even touch their differentials and it's very rare that I ever hear any of them having a problem with their differentials, you'll probably be fine waiting another 5k miles to do it at 50k.

 

[MileHigh18]

Any time I buy a preowned vehicle that doesn't have detailed service records, I always dump any and all fluids and replace with fresh ones.

 

[artificialist]

I do the first gear oil change when the manual says "Severe service" and do the rest of them based on the regular service.

I often do the change much earlier.

Anyway, the reason I make sure to change the oil is because 2 things can happen:
1. Nothing bad happens in the entire life of the car
2. Pay big $$$ in repairs at 80,000 miles

And I never know which situation I will be in. That is why I change those oils, even if the OE doesn't say it is important.

Another reason I do this is because sometimes the OEM fluid is cheaply made, and I can use a better quality fluid in its place. Many Japanese cars still use SAE90, and using a synthetic multi viscosity oil can improve MPG and lifespan.

 

[MolaKule]

Originally Posted By: MileHigh18
Any time I buy a preowned vehicle that doesn't have detailed service records, I always dump any and all fluids and replace with fresh ones.


Same here.

 

[Jasper8146]

I agree with most everything that has been said. An interesting gear oil study promulgated by Amsoil showed that by far the largest percentage of wear metals in a differential were generated in the first 7500 miles according to oil analysis of the differential conducted at various intervals. For example at 7500 the iron was around 500 ppm. They continued to sample that same differential again at around 17,000 miles and again at 50,000. The numbers were around 600 at 17,000 and 700 at 50,000. What that showed me was that if you wanted maximum life you should change the OEM fluid out sometime after 7500, but that if you didn't do that and waited till 50,000, you probably weren't hurting the diff all that much. I am planning to change out the 2 differentials in my 2011 Infiniti EX35 somewhere around 14,000 and put in Amsoil synthetic. So, in your situation, you can wait another 5k or do them now, it probably won't make much difference. If you're going to go to the trouble of doing them, I would recommend a synthetic as opposed to dino fluid.

 

[dkryan]

I changed the diffs and ATF on my wife's 2005 Highlander at 10K miles. I used Amsoil Severe Gear 75w-90 in the diffs and dumped the T-IV for Amsoil's ATF.

I repeated the above at 75k miles.

Since her ride is AWD, there was no transfer case to deal with.

No issues and no problems thus far at 105k.

 

[rustypigeon]

Originally Posted By: dkryan
Since her ride is AWD, there was no transfer case to deal with.


Do you mean FWD? The AWD Highlander does indeed have a transfer case.

 

[dkryan]

Originally Posted By: rustypigeon
Originally Posted By: dkryan
Since her ride is AWD, there was no transfer case to deal with.


Do you mean FWD? The AWD Highlander does indeed have a transfer case.



Uh oh.

Nope. It's definitely all wheel drive.

 

[Clevy]

Originally Posted By: dkryan
Originally Posted By: rustypigeon
Originally Posted By: dkryan
Since her ride is AWD, there was no transfer case to deal with.


Do you mean FWD? The AWD Highlander does indeed have a transfer case.



Uh oh.

Nope. It's definitely all wheel drive.



So how does awd work without a transfer case to transmit power to the front and rear then?

 

[supton]

From what I can tell on the RAV4, they split power out of the transmission, front/rear, no differential--solid connection. I'd say front and rear driveshaft, but the front end is right in the trans, so not old school. Anyhow, I think front and rear driveshafts (bear with me, only the rear exists but it's easier to think this way) are locked together, running same speed, hard tied together through gears.

Now the rear diff is where the magic is. It uses one or two clutches to partially engage torque to the wheels. Is it one clutch to drive the differential, or does the drive shaft drive the diff which then drives clutches which then drives wheels? I think it's the former, and high end vehicles might do the latter; I know Toyota prefers to pull brake lines to deal with traction so I'm guessing former. Anyhow, point is, with viscous couplings, front/rear are hard tied together, and the diffs were were the speed differentials / torque control occurs.

No transfer case. If we were to put it into old school terms, the phantom transfer case would be essentially locked in 4HI locked, which is really just one shaft in and two shafts out with everything running same speed.

 

[dkryan]

Originally Posted By: Clevy
Originally Posted By: dkryan
Originally Posted By: rustypigeon
Originally Posted By: dkryan
Since her ride is AWD, there was no transfer case to deal with.


Do you mean FWD? The AWD Highlander does indeed have a transfer case.



Uh oh.

Nope. It's definitely all wheel drive.



So how does awd work without a transfer case to transmit power to the front and rear then?


My 2009 Explorer (work ride) has a very distinct front and rear differential as well as a very noticeable transfer case. It's four wheel drive.

The '05 Highlander has a distinct rear diff and a PITA front diff (at least to re-fill) but I'll be danged if I can find a transfer case anywhere between the front and rear diffs.

 

[rustypigeon]

That "front diff" is the transfer case. The fill plug has a label that says 85W90 GL5. If this is the plug you pulled and filled, then you filled the transfer case.

 

[dkryan]

That's what they told me at the Toyota dealership when I called them in 2006 to inquire as to the transfer case location. Thus, my comment:

".....since her ride is AWD, there was no transfer case to deal with."

I just call it the front diff and let it go at that. That's likely an incorrect description but my focus is trying to get the gear lube into the fill hole. Draining is a cinch. But for the Amsoil hand pump I attach to the gear lube bottle, forget it!

 

[rustypigeon]

Originally Posted By: dkryan
Draining is a cinch. But for the Amsoil hand pump I attach to the gear lube bottle, forget it!


I run a length of clear vinyl tubing from the engine bay down to the fill hole. Then put the gear oil nozzle in the tubing and fill it that way. You are right, that is a pain in the rear to fill.

 

[dkryan]

Originally Posted By: rustypigeon
Originally Posted By: dkryan
Draining is a cinch. But for the Amsoil hand pump I attach to the gear lube bottle, forget it!


I run a length of clear vinyl tubing from the engine bay down to the fill hole. Then put the gear oil nozzle in the tubing and fill it that way. You are right, that is a pain in the rear to fill.


Yep! That works, too, Rusty.

 

[MaximaGuy]

I put 75W110 Amsoil in TC and diff and they work just fine in CA weathers.

The fluid is bullet proof and no seeping, last when i checked the fluid (w/ my finger) it was still golden though quite nasty smelling like when it was replaced!!!