Changing Differential & Transfer Case Fluids - Pics Included

[Bluesky 07]

Bought my '07 Sport used at 96K and have put 15K more on it. Foolishly assumed this would have been done along the way by the previous owner, who seemed to keep on top of maintenance according to the Toyota service records online.

But I went back into the detail and found that diff service was declined at 80K. Maybe it was done elsewhere or by the owner; I can only hope. In any case, I just finished ordering everything I need to get this done and will post a follow-up with pics.

BTW, thanks to the OP for the outstanding write-up and pics and to everyone who has contributed their experiences and info to the thread. Stating the obvious here but this is the kind of stuff that makes a forum like this golden.

Edited to add: I found this rust around the fill plug on the rear diff. Would appreciate opinions on whether it's anything to be concerned about.

 

[TheeMikeB]

Edited to add: I found this rust around the fill plug on the rear diff. Would appreciate opinions on whether it's anything to be concerned about.

From this pic that rust doesn't look that bad. You can take a wire wheel to it and then repaint it to prevent any further rust.

 

[JB.]

@JB.

How often should I replace Differential and Transfer Case Fluids? I cannot find anything on the subject in the maintenance section?

Didn't mean to ignore this [MENTION=101314]sr3tlaw[/MENTION] (looks like the mention function has changed), even though I don't claim to be a good source to ask.

Maintenance schedule lists changes (rather than inspection) only for towing -- 15k. Seems reasonable that it could be 2 or even 3 times that interval without towing. I would have liked to keep up with 30k intervals but haven't quite managed that. I'm much more comfortable letting the transfer case go long than either of the ends. TC oil always looks new. But it's only the front that takes time so I always do them all anyway.

 

[sr3tlaw]

Didn't mean to ignore this [MENTION=101314]sr3tlaw[/MENTION] (looks like the mention function has changed), even though I don't claim to be a good source to ask.

Maintenance schedule lists changes (rather than inspection) only for towing -- 15k. Seems reasonable that it could be 2 or even 3 times that interval without towing. I would have liked to keep up with 30k intervals but haven't quite managed that. I'm much more comfortable letting the transfer case go long than either of the ends. TC oil always looks new. But it's only the front that takes time so I always do them all anyway.

Thanks!

 

[2003-4x4runner]

This is some great info. :whoo:
I just had the two diff's oil changed at my 150k service and I noticed that my rear diff fill/drain plugs are clean. Its almost like they never changed the oil? Shouldn't there be some oil residue on the plugs? It makes me want to change them again or at least check the color of the oil.

 

[Bluesky 07]

Searched but couldn't find an answer to a question about the right gear lube...are there two variants of Mobil 1's 75W-90 synthetic gear oil? There's the one with a special limited slip additive (bottle is marked "LS") and I've seen the same product with no "LS" as well, though the LS is much more common. Is the LS the right one?

Just to be clear, obviously I saw people in the thread used the Mobil 1 LS but I want to verify that it's the correct choice (or an acceptable one) given that another variant may exist.

 

[Top Shelf Synthetics]

Searched but couldn't find an answer to a question about the right gear lube...are there two variants of Mobil 1's 75W-90 synthetic gear oil? There's the one with a special limited slip additive (bottle is marked "LS") and I've seen the same product with no "LS" as well, though the LS is much more common. Is the LS the right one?

Just to be clear, obviously I saw people in the thread used the Mobil 1 LS but I want to verify that it's the correct choice (or an acceptable one) given that another variant may exist.

You can use the "LS" in a non-LS diff. The LS has some additives/friction modifiers to reduce chatter in an LS diff. LS gear oil is usually a little more expensive and the service life is not as long, you may have to change it more frequently. I would recommend sticking with a normal 75W-90, non LS. I personally use Amsoil SVG, 50K mi service interval.

 

[Bluesky 07]

I finally got to this and had no problems thanks to this thread. Really appreciate the OP's post, especially the pics, and everyone who shared their experiences as well.

Which brings me to something I did in response to the posts about the gear oil spurting out. We had an old pitcher around the house so I held it up to the drain hole to catch the gear oil from the front diff and transfer case. Worked well - no spillage. It also allows you to get a good look at the oil and to measure how much comes out if the pitcher has markings. Finally, it's a great storage place for your bottle pump. A similar pitcher is about $3 at Walmart. (My waste oil container has one of those plastic grids across the opening so it catches the plug when the oil is poured out of the pitcher.)

As I suspected, the front and rear diffs appeared to be the factory fill. The pic, which looks like a pitcher of cola, shows the front diff oil. Not so good I suppose at 112K; wish I had thought to do this when I bought the truck at 96K. But there wasn't an alarming amount of metal sludge on the drain plugs, and since changing the past isn't one of my strengths, I'll let that go and just keep the oil fresh from here on out.

The transfer case oil was kind of honey colored, almost exactly like motor oil looks right out of the bottle. The dealer I where I bought the truck used had to replace the 4WD actuator so I assume they had to open the transfer case to do it.

All in all, the info in this thread made this an easy job. I hit the plugs with WD-40 that had a couple of weeks to penetrate and each broke easily. Bought this torque wrench from Amazon to be sure I got the plugs tightened correctly.

The wrench works very well, is unexpectedly hefty and solid for the price, and comes with a nice storage case. It's available in 3/8 drive as well if you prefer that over 1/2. I checked each plug with my old beam-style wrench to be sure the the torque was correct and it was. (Bought the new wrench because it's much more precise than a beam-style.)

So that's it for what it's worth. It makes no sense to pay someone to do this job and I hope this post makes things easier for anyone who decides to DIY it.

 

[sr3tlaw]

I just need a breaker bar

 

[metramm]

Thank you for the detailed instructions on this maintenance. I used your guide to change the diff fluids in my new to me (purchased 2 weeks ago) 2006 4Runner Limited 4x4 4.0 V6.

Had 126k miles on it when I purchased it but I didn't have service records of the Diffs/coolant.

ended up changing the following:

spark plugs with NGK Iridiums (gap was almost a .080!!)
Performed compression test because I was concerned about the possible head gasket issue. Passed with flying colors!
Diff fluids (front, center, and rear)
Engine coolant with Toyota pre-mix from dealer
Oil change with Toyota filter (might as well since I had the skid plates off)
Lube the driveshaft zerk fittings (found page on this forum on how to do it)

Very easy to change as others have posted. I used the Mobil 1 80w 90 LS gear oil that others have mentioned. Seems to drive smoother and my gas mileage increased by 1mpg on the 2 hour drive home!


Thanks again and keep up the awesome posts!

 

[deepsearunner]

transfer case box?

weird question, what is the black plastic box on the transfer case?

 

[Drunner97]

weird question, what is the black plastic box on the transfer case?

The 4wd actuator.

 

[oesterj1195]

Yes thank you for this post. I used it to save a great amount of time changing out all my differentials. Other then taking the wrong skid plate off it was pretty painless. And after 180k miles the transfers case oil did not look that bad. I don't know if you ever need to change that unless you are heavy 4wd user. Front and rear were pretty black!

Interesting I went from dino to synthetic and didn't notice any difference in mileage...if anything it went down. I used 80w/90 amsoil on all of them.

 

[Ju1cE82]

On the to do list for this evening! Hope everything comes apart and with 185k on my new rig hope this has been done a handful times already!

 

[Pilotamis]

Thank you everyone. Sprayed everything down tonight and assuming the dealership has everything in stock I'll do this tomorrow evening.

 

[Silver4RunnerIS300]

Just did all of this. Thanks for the write up.

Sent from my SAMSUNG-SM-G900A using Tapatalk

 

[firstrunner08]

do it yourself!

Just got back from an oil change as I live in an Apt and didn't want the "hassle" of changing my oil. Well, that's the last time i do that! $120 for oil, oil filter, and air filter! Plus, they quoted me $79 for EACH front diff, rear diff, and transfer case. So the total would be 237 plus tax. Going to do this soon on my own! Thanks all

 

[DK327]

Just got back from an oil change as I live in an Apt and didn't want the "hassle" of changing my oil. Well, that's the last time i do that! $120 for oil, oil filter, and air filter! Plus, they quoted me $79 for EACH front diff, rear diff, and transfer case. So the total would be 237 plus tax. Going to do this soon on my own! Thanks all

I never changed my own oil before getting my 4runner recently and after doing my differentials and greasing the driveshaft, I don't know why I've always paid someone else to do it... I feel like a chump!

 

[hojodro]

I'm in the process of ordering supplies to change out front/rear/tc fluids soon, but I want to ensure I'm getting everything that is needed. I've got 94k miles on my 08 sport, bought it with 82k, but I don't see any service records indicating fluid changes.

Other than the oil for all 3, is it a requirement to change out the drain and fill gaskets when replacing the fluids? Basically, if someone could give me a shopping list of things I'll need that would be great. My lack of knowledge is limited in the mechanical arts, so I don't want to screw anything up. Thanks in advance.

 

[GX4X4]

I'm in the process of ordering supplies to change out front/rear/tc fluids soon, but I want to ensure I'm getting everything that is needed. I've got 94k miles on my 08 sport, bought it with 82k, but I don't see any service records indicating fluid changes.

Other than the oil for all 3, is it a requirement to change out the drain and fill gaskets when replacing the fluids? Basically, if someone could give me a shopping list of things I'll need that would be great. My lack of knowledge is limited in the mechanical arts, so I don't want to screw anything up. Thanks in advance.

I would just replace the gaskets, they are like $1-2 each even if you go to the dealer and pay full retail. if there is a leak when you reuse the gasket you have to drain the fluid and do it again (fluid is expensive). The transfer case one uses an aluminum washer and if you look carefully at the old one, you can see the indent of circles on both sides, you will not be able to put it back exactly and the only way to get it to seal is to overtighten the plugs to crush the gasket more than the first time, which you don't want to do to the aluminum transfer case. Or you will just get a very low seepage leak just enough to make a grimy mess. So replacing the gasket is very cheap insurance.

page 1 has all the part numbers