Trail Maintenance: Driveline fluids, how and when to change them

The topic of oil in vehicles is the easiest way to spark a debate on the internet in the gear head world. To be honest I am not sure how, when or why this trigger developed, but I can say that it ultimately causes a lot of confusion on which fluids to use where and when to change them.

Having done an extensive amount of research on the subject of driveline lubrication for these 4Runners, I want to share what I have found and the regimen that I follow.

Note: These are my recommendations, and ultimately you should refer to the owners manual, or your local mechanic for exact specifications to suit your individual conditions.

Parts required

Crush Washers:

Gear Oil (as recommended by Toyota):

Service intervals (as recommended by Toyota):

  • Differentials: 15,000 miles when heavily loaded, or with roof-mounted gear
  • Transfer case: 30,000 miles when driving dirty or dusty roads

Both of those intervals assume that the vehicle is under those conditions constantly. Toyota recommends that under “standard conditions” fluids be replaced as needed based on levels and color. My personal regimen is to replace all driveline fluids at 30,000 miles. This is a reasonable interval for the weekend warrior to keep their driveline healthy.

Other items for driveline service:

Differential gear oil options

Gear oil in differentials is a pretty straightforward choice. Stick with the manufacturer weights, and required additives and you’re home-free. For the 4Runner, Toyota recommends using 75w-85 GL-5 gear oil in both the front and rear differentials. Unfortunately, the options for this specific weight are limited including OEM and some third party products. For this reason, many DIYers will use a more widely available 75w-90 GL-5 gear oil as it easier to find in-store and is generally cheaper. This substitute is very heavily discussed on a number of online forums. To summarize, it’s a very popular swap and over the seemingly thousands of posts that I have read through there hasn’t been a differential failure that was pinned directly on the misuse of gear oil weights for the 4Runner. When choosing your gear oil (regardless of weight), be sure to use a full synthetic gear oil for optimal protection against wear.

Transfer case gear oil options

Here is where Toyota makes things more difficult, and where the controversy begins.

Toyota specifies their Genuine Transfer gear oil SAE 75w or equivalent as a proper fluid for the transfer case. The problem is that this weight of oil is very uncommon. So uncommon that the only 75w options available are the original OEM fluid, and Ravenol’s SAE 75w manual transmission fluid. To make things more interesting, Redline specifies that their 75w-85 is a substitute for SAE 75w weight oils (matching OEM specs). The one big caveat to these options, are that neither of them are a direct match for the OEM fluid. The reason for this is that Toyota hasn’t disclosed the formula for their 75w transfer gear oil, so third party companies haven’t been able to create an equivalent oil matching Toyota’s specs.

[Edit 12/28/2018]: Royal Purple Synchromax Manual Transmission Fluid is also recommended by Royal Purple as a suitable replacement for the Toyota Genuine Transfer gear oil. They also have a guarantee that states any defects or problems caused directly by the use of their recommended product will be covered for repair by Royal Purple.

To try to sort things out, forum members have contacted Redline directly asking for a recommendation on Toyota transfer case fluids. They consistently respond stating that they don’t have a recommendation because they don’t have access to Toyota’s specifications. In addition, the Ravenol fluid has been compared directly to the OEM fluid by submitting virgin samples to Blackstone Labs. The results showed a similar composition, however, the Toyota brand fluid contained a number of additives that supposedly are designed to help protect the specific transfer case components from excessive wear.

[Edit 10/2020]: Red Line Oil has developed a new fluid that is a direct replacement for the Toyota Genuine Transfer Gear Oil LF 75w. I contacted Red Line directly to ask them for an updated recommendation, and they state that the new MT-LV 70W/75W GL-4 Gear Oil is a direct replacement for the OEM fluid. I wouldn’t hesitate to use this fluid in your transfer case if you prefer their product.
Click here for the Red Line MT-LV 70w/75w GL-4 Gear Oil product page

Why the great debate? Why not go with the Toyota fluid? The biggest factors are cost and availability. Toyota Genuine SAE 75w Transfer gear oil is notoriously hard to find, and by comparison very expensive. When asked, some dealers can’t order the fluid directly. Thankfully online distributors make purchasing the Toyota fluid easier, and a bit more affordable. Most costs range from $60 to $90 per 1 liter can, depending on shipping and source. This is much more expensive than third-party alternatives which is why many people stray from the OEM “liquid gold” when changing their fluids.

There is one more alternative to add to this mix. It’s well documented that another popular fluid replacement for the 4Runner transfer case is the easy to find 75w90 GL-5 weight gear oil. Many have used this weight with no issues that have been a direct result of improper fluid weight. I personally used Redline 75w90 in my transfer case for approximately 30 thousand miles without any negative side effects. When researching the subject keep in mind that while some will tell you on a forum thread “if you use fluid other than the Toyota specified gear oil your transfer case will blow up”, there aren’t any specific examples of a transfer case failing due to improper fluid.

The Bottom Line

Depending on your specific usage, your intervals for changing transfer case gear oil will range from approximately 30 to 60 thousand miles. For that service interval, the cost of purchasing the more expensive Toyota fluid is worth it. Knowing that it’s exactly what the transfer case needs to perform at its peak makes the initial price easier to swallow.

Plug locations

Changing your fluids

Changing gear oil in these 4Runners is a very simple process. I will run through that process first, followed by some tips for the individual housings to make the fluid change easy!

Before changing the fluids, take a 5-10 mile drive to warm up all of the fluids in the drivetrain. Warm oil is less viscous and will drain quicker and more completely.

Draining

Both axles and the transfer case have a drain plug, and a fill plug. Each one of the plugs have their own crush washer (see the beginning of the article to see which one goes where).

To drain the fluid remove the fill plug, and after placing a receptacle under the housing, remove the drain plug. Removing the fill plug first will allow the fluid to drain freely and quickly. Let the fluid fully drain.

All of the drain plugs have a magnets that collects any metallic debris in the oil. These need to be inspected for any large chunks, and wiped clean during every fluid change. Some “metallic paste” is normal to see between fluid changes, so fear not if you have some to wipe off. Reinstall the drain plug along with the appropriate crush washer and torque to spec.

Filling

The fill capacities are simply as much as the individual housing will hold before coming out of the fill hole (actual specs above). You’ll want to fill them on level ground using a hand pump and a tube to keep spills to a minimum. When fluid begins to drip out of the fill hole, give an extra couple of pumps when you remove the tube. Let the excess spill out until it stops. Reinstall the fill plug along with the appropriate crush washer and torque to spec. Clean all of your housings with a good degreaser to keep an eye on possible leaks.

Front differential tips:

  • Remove the skid plate first, providing easier access to the differential.
  • Before reinstalling the skid plate, drive for about an hour and let it sit overnight to check for potential leaks.
  • Make sure you have a few socket extensions on hand. It’s a tricky spot to work in, find the best combination based on your tools.

Transfer case tips:

  • Use an old-fashioned can opener to open your Toyota gear oil can (if chosen). One with a pointed end. Then use your hand pump to pump directly from the can.

Rear differential tips:

  • Remove the spare tire first to give you extra space while servicing the rear differential.
  • Check your stock or aftermarket differential breathers while you’re under there to make sure they’re functioning properly.

Enjoy the miles you put on your 4Runner by making sure that it’s healthy and ready for the next adventure!

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OverlAndy @ ATWProjects
OverlAndy @ ATWProjects
3 months ago

Please HELP!
The Redline Diff oils in your photos are the bottles that say “for hypoid limited slip differentials.”
I have found these exact bottles on Amazon. Then there is a Redline 75w90 that does NOT say “for limited slip differentials.”
Question is: Can we use the stuff that says it is for hypoid limited slip differentials?
In an SR5 4×4?

Mike
Mike
3 months ago

Very informative write up Max! Just ordered all the materials. Looking forward to saving money and doing this all myself. Thanks!!!

Joe
Joe
3 months ago

I have read in some other forums about some users having bad luck with the Mobile1 75W-90. Some have suggested adding an LS treatment for the differentials or there may be some ‘chattering’ after 3k-5k miles. Any experience with that?

Last edited 3 months ago by Joe
Tanner H
Tanner H
4 months ago

Hey Max, I’m late to the party here but thanks for the write up! Wondering if anyone has opinions about transmission fluid changes in our 4Runners. It seems like there’s not agreement about when to change ATF or whether you even need to change it at all. Does anyone have specific thoughts?

Joe
Joe
4 months ago
Reply to  Tanner H

As noted below, I do regular drain and fills on each of the transmissions with Ravenol ATF Automatic Transmission T-WS fluid. During each drain and fill I am removing and adding back a little over 3 quarts. I do this about every 30k miles. I think 50k under “normal” conditions is good insurance.

Nick
Nick
6 months ago

I f’ed up . Used the wrong crush washers for the rear diff… and didn’t realize until I did the transfer case and didn’t have two crush washers I needed. So I used transfer case crush washers on rear diff. And the transfer case fill plug now has a rear diff crush washer… they aren’t leaking…. should I just roll like this? Keep an i on it?

Joseph Pickel
Joseph Pickel
6 months ago
Reply to  Nick

Yup – you should be fine. Just keep an eye on it.

Brandon
Brandon
7 months ago

Looks like someone’s made a bundle of all 6 needed washers.

Differential and Transmission Drain Plug Crush Washers Gaskets Fits for Toyota 4runner Tacoma Tundra FJ cruiser Land Cruiser, Replacement for the part# 12157-10010 90430-24003 90430-18008

Dan
Dan
7 months ago

Your link for the transfer case washers leads to the incorrect product.

Dave M.
Dave M.
11 months ago

Thank you for writing this. Makes following steps/with pictures of drain/fill plugs much easier and confidence inspiring.

I have a 2011 4Runner Limited 4WD. Yes, the limited has slightly more fluid capacity in the transfer case as opposed to the part-time brothers.

I use (5 quarts total) Royal Purple 75w-90 for differentials, and (2 quarts total) Royal Purple Synchromax for transfer case.

I also would consider Redline 75w-85 or Amsoil 75w-90 for differentials. All great fluids as well, but I believe only the OEM Toyota transfer case oil and Royal Purple Synchromax are confirmed for the Toyotas.

Andrey
Andrey
1 year ago

I stopped by Toyota service center the other day and asked what oil they use for diffs and transfer case. They said they use regular 75w-90 on diffs and transfer. Since i have limited edition with torsen LS transfer case, he recommended adding FM (friction modifier) to the transfer case also known as Limited Slip additive, that can be purchased anywhere.
My research on FM, it’s only needed on limited slip diffs that are clutch based (that 4runner does not have), torsen is just a set of gears, so not really needed, however adding FM does not hurt even on open diffs and seems to be beneficial, as it coats gears nicely and reduces friction overall.
I ended up using Mobil1 75w-90 LS on both diffs and transfer case (it has already LS additive in it). It costs 13$ QT in my location and way cheaper than Toyota’s one.

Service center guys do admit Toyota is full of s** trying to sell expensive oil to users while using cheap conventional one in the dealerships, but that’s just a marketing thing for Toyota to make more money out air.
I also called a couple more Toyota service centers while looking for genuine 75w for the transfer case, they don’t even sell it in my geo and they all use 75w-90.

And Max, thank you for posting such a good report.

Joe
Joe
1 year ago

Max – Thank you for creating what has become the reference guide to changing the 4Runners driveline fluids.

I have three 4Runner’s, 2-Limted’s and 1 TRD OR, and have changed the drivetrain fluids many times in each. In my Limited’s; I replaced the front differential fluid with Amsoil Severe gear 75W-110, my 4Runners are in southern FL and tow a bit. The Limited’s being AWD I find going with 75W-110 in the smaller capacity front differentials gives a little bit more protection. In the TRD front differential I use Amsoil Severe gear 75W-90 as this trucks has minimal 4 wheel drive activity.

In all the rear differentials I use Amsoil Severe gear 75W-90. In all the transfer cases I use Royal Purple Synchromax Manual Transmission fluid which protects the soft metals found in the Toyota transfer case. With plus 400,000 miles logged across my three 4Runners I have yet to have any issues in using these fluids.

Dave M.
Dave M.
11 months ago
Reply to  Joe

Did you add FM(friction modifier) to the transfer case along with the Synchromax?

Joseph Pickel
Joseph Pickel
4 months ago
Reply to  Dave M.

No, it’s not needed

Joe
Joe
1 year ago
Reply to  Joe

Also – I do regular drain and fills on each of the transmissions with Ravenol ATF Automatic Transmission T-WS fluid. During each drain and fill I am removing and adding back a little over 3 quarts. I do this about every 30k miles.

Chris
Chris
1 year ago

Is the transfer case capacity the same for a 2016 Limited Model? I know the Limited is the only model with AWD, but am not sure if the transfer case and fill capacity (1.1 L) are the same as other models? I have been unable to identify this Limited capacity with online searches so far.

Chris
Chris
1 year ago
Reply to  Chris

I answered my own question. Found that AWD (Limited) Transfer Case requires 1.5 QTs (1.4 L). I just can’t justify $120 for two cans of OEM 75W plus $20 shipping? Any experience or recommendations regarding Rensoil 75W (I read reviews that independent testing suggest similar viscosity ~ 6 to OEM, but OEM has additional protective additives? Also, one review suggested another batch testing was not consistent to listed standards?

How about RedLine 70W/75W? It has other applications and is GL-4, so expect it would have less “protective additives” than OEM also?

I have also seen Amsoil Severe Gear 75W-90 used, though they did not list this as a recommended equivalent for the Transfer Case oil? I will be using this in my diffs, as viscosity is about equal to the range for OEM recommended 75W-85, but at ~ 12 is still twice as thick as the 75W recommended for the Transfer Case.

I realize many are using 75W-90 in the transfer case, and dealerships have stated they do, as it “meets or exceeds OEM Specs,” but realistically, it is just cheaper and more readily available in bulk.

4th Gens used 75W-90 in the transfer case, with, I believe, change intervals of 30K. I understand Toyota started using lower viscosity, 75W to decrease rolling friction (?) and improve gas mileage, but sure you won’t save that much on gas? Just don’t know if there is any difference/change to the5th Gen transfer case internal parts that would require the additional protection of the OEM fluid?

Thanks, in advance, for all shared experience and opinions.

Dave M.
Dave M.
11 months ago
Reply to  Chris

I used Royal Purple 75w-90 for the differentials, and Royal Purple Synchromax for the transfer case. Others have used this as well with no issues.

Other options is the RedLine 75w-85, or Amsoil 75w-90 for differentials. Redline and Amsoil do not yet have a replacement transfer case fluid for Toyotas, like Royal Purple Synchromax.

Dave M.
Dave M.
11 months ago
Reply to  Max Sheehan

I missed that. Thanks. Noted.

Chas
Chas
1 year ago

I truly appreciate your site, its a great resource, so Thank you up front! – So, I’ll just give my 2 cents — I went to the Redline website and it lets you plug in your make/model etc for their transfer case oils, mine is 2018 off-road (5th gen) , and the website says use their MT-LV 70W/75W GL-4 gear oil. . so I’m perplexed, anyways I’m not too concerned, just like to do my research, I’ll probly still used the Redline 75W-85 (or -90) ,, but this may be something / or , maybe nothing. Thanks again for your excellent site! –Chas

Chris
Chris
1 year ago
Reply to  Max Sheehan

Hi Max, Great advice, I was wondering if Amsoil gear oil can be used in 5th gen transfer case? please and thank you.

Wildman
Wildman
1 year ago

I just bought a 2013 TE with 110k on it. Not sure if any driveline fluids have been changed before but the rig does show some signs of mild/mod trail use and probably some towing. Should I be changing any diff/tcase fluids at this point? I plan to use it as a DD, no towing, until at least 150k-175k before building it out.

If I should change fluids will 1qt of Toyota transfer case oil be enough or is the 1.1qt a hard cutoff? It’s so expensive I’d rather not have to buy a second quart if possible. How about topping it off with any leftover gear oil I have if needed?

Thank you!

Tyrebyter
Tyrebyter
1 year ago
Reply to  Wildman

The Ravenol and the OEM are sold in 1 litre. That’s your 1.1 qt.

christopher alexander
christopher alexander
1 year ago

Hey Max, great write up! I just changed my front diff oil after replacing the axle and my 4wd sensors seemed to have been tripped because I’m showing the lights on the dash. Ever hear of this happening and what do you recommend?

Max Sheehan - @life.to.the.max
Max Sheehan - @life.to.the.max
1 year ago

I haven’t heard of this related to a differential oil change. What lights are specifically coming up?

christopher alexander
christopher alexander
1 year ago

I now actually think it has to do with unplugging the abs wheel speed sensor because I have the abs, brake, 4wd, and traction control lights all lit up on my dash. I thought maybe the 4wd lights came on when changing diff oil, but I don’t know why that wild occur. I think it has to do with an electrical/computer situation that I have tried to troubleshoot but have not found the solution!

Matt
Matt
1 year ago

Awesome post! Found this guide that lists all the fluids and stuff needed for the entire 4runner.
https://www.toyota-4runner.org/5th-gen-t4rs/285126-beginner-fluid-maintenance.html

Dax
Dax
1 year ago
Reply to  Matt

Good resource for sure, it would just be nice if the information was structured better over there. Kinda hard with the nature of a forum though. Not sure why some people are still writing for t4r org when everything is so much more organized on Trail4R and they pay you. I’ll always love the forum but trail is growing on me.

Christopher Robinson
Christopher Robinson
1 year ago

Hi Max,

Read the following from your post re Rear Diff Tips: “Check your stock or aftermarket differential breathers while you’re under there to make sure they’re functioning properly.” Is this only on the rear, or both front and rear? I am really not familiar with what differential breathers are. Would you have a photo to identify it, and what is the procedure for test these?

Thank you,

Chris

bhl
bhl
1 year ago

This was awesome! I did both diffs and the transfer case at 47K miles. I would say less than 5% of my driving is in 4×4 mode (2016 Trail Edition). I found that the transfer case oil was pristine and would venture to say that I could have easily gone to 100K miles without degradation. That said the rear diff oil was filthy black and definitely needed changing. The front diff oil was about half way between the transfer case and rear diff. I went with the Redline 75W85 for all three fills. The volumes you list in the table are spot on.

Guest
Guest
1 year ago

For us crazy Canucks up north, napa carries a esso 75w oil, (exxon for you yanks) in 20L pails for about 140 cdn , which work out to what 5 bucks usd (joking only slightly) they even have have a larger size. This weight oil seems common in mining equip in colder climates. All the dealers here use it but charge the toyota 75w prices…..

Jeff Mills
Jeff Mills
1 year ago

Owner – 2015 4Runner TRD Pro. Just got off the phone with the service department at my local Toyota dealership, Cloninger Toyota, Salisbury NC. Get This! They use and recommended for me to purchase the 75W-85 GL-5 for the Transfer case. I asked them repeatedly, (Two Different Tech Service folks) if this was correct and stated the SAE 75 LF recommendation in the owners manual. They said they use the same gear oil in all three , transfer case, front diff and rear diff. Go figure….. I’m going to use Amsoil Synthetic SAE 75W-90, API-GL5 Gear Lube in all of them.

Dan Lloyd
Dan Lloyd
6 months ago
Reply to  Jeff Mills

How well did the AMSOIL 75w90 work out? I just changed my front and rear using the AMSOIL, but not the transfer case. 1st service @10. I’m still deciding on transfer case lube. 2020 TRD OFF ROAD.

Matthew W Rebbert
Matthew W Rebbert
2 years ago

How many liters of the LF 75 transfer case oil did you use? I see 1.1 to 1.5 quarts which seems like I need a can and a half of that “liquid gold”. I have the 2017 Limited which is full time 4wd.

Don Love
Don Love
2 years ago

I used 1.1

william strumfels
william strumfels
2 years ago

Hears my two cents about transfer case oil..I bought a brand new 2011 4runner Trail back in 2011 and changed the transfer oil to Amsoil 75w/90 weight before I had 500 miles on it and at traded it in time with 115,000 miles for a 2019 Trail and had zero problems, or did I…Hears what I think I learned …Over the years the 2011 was hard to get in to low range,I just thought that’s the way it was and I hardly ever used low range so no big deal.But jump ahead to my new 2019 it snaps right in to low range ,the 2011 with 75w-90 never ever did that,or did it when brand new with Toyota 75w oil in it..see I cant compare I changed the oil at 500 miles so that was the whole time I owned it.. The question is now do I put 75w-90 in the transfer case and see if that weird problem happens again or just go with 75w Toyota oil?

Mike
Mike
2 years ago

Great write up! Just a heads up, you have the sockets needed and torque specs reversed for the differentials in the “Parts Required” section. Great trip reports and how-to’s as always.

Don Love
Don Love
2 years ago

Royal Purple claims that their Synchromax Manual Transmission fluid is a direct replacement for the Toyota Type LF fluid used in the transfer case. They show it on their website and in the FAQ section as being a compatible fluid. I have used it for years in my Tacoma transfer case and plan on using it in my new 4Runner. From my research the issue is there are soft metal bushings in the Toyota transfer case that may become damaged over time if using a fluid with high phosphate content. Synchromax is significantly less expensive than they OEM fluid and Royal Purple backs the product with a warranty that if the use of their product is directly related to a failure they will reimburse you for the cost of repairs.

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