Changing Differential and Transfer Oil on 5th Generation

I wanted to make a post specifically for 5th generation diff and transfer case oil change. Hope this helps!

Tools you will need:

Torque Wrench (1/2 inch)
Socket wrench
24 mm socket
10 mm hex bit
10 mm socket
oil pan
oil pump: https://www.amazon.com/gp/product/B000BQW5LK/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
PB blaster

Parts you will need:
Differential and Transfer Case Oil. You can use OEM or a good synthetic. I used Mobil 1 75w-90 LS and it worked great.
If you aren't comfortable using aftermarket, you can buy the OEM oil, but in my opinion, they are overpriced.

Crush washer replacements:
12157-10010 TAKES QTY 3 TWO FOR REAR DIFFERENTIAL AND 1 FOR FRONT DIFFERENTIAL
90430-24003 TAKES QTY 1 FOR FRONT DIFFERENTIAL
90430-A0003 TAKES QTY 2 TRANSFER CASE

Do NOT reuse the original crush washers. They must be replaced with every oil change or you will experience leaks. Here's a kit that I found on Amazon: https://www.amazon.com/gp/product/B017V4BAXI/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

BEFORE YOU GET STARTED:
Spray all the bolts with PB blaster before you remove them. I did this and waited about an hour before I removed them. Some people like to wait overnight which is preferred, but I didn't want to wait that long.

Make sure your vehicle is on level ground or you will not be able to fill oil to appropriate volume.

HOW TO REPLACE YOUR OIL
Front Differential
Step 1: Remove skid plate using a 12 mm socket . There are 4 bolts that you will have to remove to access the front differential.

Step 2: Remove the FILL bolt using the 10 mm hex bit. Always remove the fill bolt first. If you remove the drain bolt, and then can't get the fill bolt off, you won't have any way to refill the oil.

Step 3: Remove Drain bolt using the 10 mm hex bit.

Step 4: allow time to fully drain. I pumped some extra oil through the system to remove any excess sludge, old oil, etc.

Step 5: Clean drain bolt, replace crush washer, and tighten to 48 ftlbs

Step 6: Add the new oil using the oil pump. Front diff calls for 1.2 quarts, but the oil will start to flow out of the fill hole when it is full.

Step 7: Clean fill bolt, replace crush washer, and tighten to 29 ftlbs

Rear Differential
Step 1: Remove the FILL bolt using the 24 mm socket.

Step 2: Remove Drain bolt using the 24 mm socket.

Step 3: allow time to fully drain.

Step 4: Clean drain bolt, replace crush washer, and tighten to 36 ftlbs

Step 5: add the new oil. Rear diff calls for 2.6 quarts.

Step 6: Clean fill bolt, replace crush washer, and tighten to 36 ftlbs

Transfer Case
Step 1: Remove the FILL bolt using the 24 mm socket.

Step 2: Remove Drain bolt using the 24 mm socket.

Step 3: allow time to fully drain.

Step 4: Clean drain bolt, replace crush washer, and tighten to 27ftlbs

Step 5: add the new oil. Rear diff calls for 1.1 quarts.

Step 6: Clean fill bolt, replace crush washer, and tighten to 27ftlbs


Overall, this is a pretty easy task as long as you buy all the parts first and have a good plan going in. It took me about 2 hours in total...pumping the oil is the longest part of the process.

 

Nice write up! For what it's worth, if you have an amsoil dealer nearby, they make gear oil in bags that is significantly quicker, easier, and less messy than using a pump. Just point and squeeze.

 

Thanks for the info! I'll remember that for next time. Pumping is a pain in the a**

 

Yeah that is really cool! Thanks for that.

 

on your use of mobil synthetic gear oil in the transfer case IMO not the proper fluid. this is the transfer case fluid new unused. see the special additives in this toyota transfer case fluid ..

mobil synthetic 75-90 does not have these additives this can cause bearing and other damage .. also may cause delayed engagement.. 30-40K miles is the recommended change.

 

When do I change the differential and transfer oil

 

Assuming you have a new or newer vehicle read your manual in the service interval section. Many people on this site have done it at around 3,000 miles and swear it's needed that soon. In my opinion (and only my opinion) that's way over-kill but hey to each his own! If your that concerned about doing it read the manual and move in Toyota's recommendation by 10,000 miles.

 

OP......Thanks excellent write up I was going to try my own when ready, I'll follow these steps and maybe even buy the washer kit and pump you show. I'm going to get the fluid(s) from Toyota so I'll need the pump. I really like the suggestion about removing the filler plug first some people may not think to do that. Mind if I make one small suggestion?? How about driving the vehicle first and warm up the fluids to aid in ease of draining?

 

Don't forget new washers for the drain and fill plugs when you get the oil.

 

Actually ordered the pump and washer kit from the OPs original post. Way to soon for me just putting them away.

 

Is it really 10,000 miles? I don't remember the manual saying a dif/transfer case oil change was necessary with the first motor oil change.

I guess I need to take a second look.

Edit: 1st mention of a dif (front and rear) oil change was at 15,000 miles at towing or heavy load conditions.

1st mention of a transfer case oil change was at 30,000 miles at towing or heavy load conditions.

 

No it's way further away I'm saying if you don't like their recommendation move it in 10,000 miles. I'm strictly guessing as I type this but the manual probably says like 60,000(ish) miles so I'm saying 50,000 should be comfortable.

 

Ah, I see.

I went through the manual this morning and there was no recommendation for changing the difs, transfer case or transmission oil unless the vehicle is used in "extreme" driving conditions. Towing, heavy offroad use, ect....

Not sure what to think about that.

I wouldn't qualify as a driver in extreme conditions, but I would want to change all those oils at some point.

With most of my vehicles in the past, that oil would be changed around the 100,000 mark and I never had an issue up to 250,000 miles when I got rid of them.

The one vehicle (Ford Ranger) that I did change the oil religiously at 3,000 miles (motor) and 30,000 miles (dif an trans) went through a motor, trans, and rear-end all using Mobil 1. Probably just a Ford thing, but it didn't give me much confidence in Mobil 1 either.

 

Is the 3,000 mile mark a misprint? That is before the first oil change!
I read down below that between 30,000 - 60,000 miles depending upon driving conditions.
I usually do those & tranny fluid every 60,000 miles in my work trucks. My '94 Cummins Ram needs it every 15,000 but those torque monsters are known transmission eaters...

 

most change the transfer case oil at 30-40K miles .the rear/front diff needs to be checked for level and condition.. if looks grayish or black then change the diff oil...I did it @3K miles but now 25K on my runner the diff oil looks like new .. so a break in caused it.

transmission fluid also requires checking but it is a PITA to check the level.most change the transmission fluids 70-120K miles but that is variable depending on the operation ... high speed in hot climate do it at 70K if a mall princes then 120K miles

 

I did mine at 20000. I tow a lot and run in 4x4 frequently so I feel my 4 classifies under the extreme driving conditions category. I am approaching 30,000 miles and have not decided what to do with the trans (may wait until 60k) but I plan on changing the transfer case then.

 

Drained and filled the rear diff today on my 2019 TRD Off Road. Odometer was only at 4200, but after viewing the specs for the oem 75W-85 fluid, let's just say I was not too impressed and wanted to put in something better. I settled on Motul Gear 300 75W-90 full synthetic (no LS additives), as it meets both GL-4 and GL-5 and will work just fine in the transfer case if I ever need to top it off.

Factory fill was 2.8 liters, but it took 3.2 liters to reach the fill hole. The vehicle was perfectly level in my garage, and didn't move forward or backward in neutral.

The drain plug had a fair amount of paste and some fine metal flakes on it. The oil was dark gray, which I assume is from the paste. Guessing it's some kind of lapping compound to help the parts wear in together.

I used the correct oem crush gaskets, and was surprised to find out they are steel (same for the originals).

I'll probably wait until 60k miles to drain the front diff and transfer case. Just wanted a better fluid in the rear since it does all of the work in 2wd which accounts for almost all of my mileage.

 

Great write up. I’m due to change my dead dinosaurs too. My T4R is running like brand new and want to keep it that way. Antique tags coming in 2021!!!

 

Agree with you. Using regular synthetic gear oil can cause deterioration of the soft metal (brass, copper) bushings in the transfer case because of the high phosphates. Royal Purples Synchromax is also considered to be an acceptable replacement fluid for the transfer case and is significantly less than Toyota’s LF fluid.

 

I used Synchromax. Works great.

 

check the drive train fluids for level and condition ..3K miles I changed my rear diff gear oil .. very dark had specks in it.. 23K miles and gear oil looks perfect.. rear diff break in !!

 

I changed my rear diff fluid at 4200 miles just because I wanted to put in a better fluid. The factory fluid was dark gray - almost black, and there was a lot of black paste and fine metal on the drain plug magnet. The discoloration is no doubt caused by some kind of paste they add at the factory.

By comparison, at 4200 miles the engine oil was barely starting to darken, and that oil gets much hotter than the gear oil in the rear diff.

 

Does anyone add an anti-foaming agent like GM Limited slip diff’s?

 

I have a 1996 GM sedan with limited slip diff.. the toyota does not require any limited slip additive it is a open diff with no clutches. the GM limited slip diff have clutches which is why I have to add the additive so the clutches will cause the axles to slip. the axles are always in the locked position so If I did not add this additive the diff would chatter on turns .

using a synthetic gear oil like mobil 75-90wt with the LS on it will not effect the rear diff on Toyota.
on my GM sedan I must use the GL5 80-90wt gear oil .. conventional ...then add the 4OZ of the slip additive.

 

Not sure what others experiences are but I have never replaced crush washers on any vehicle I have ever owned. Even a honda civic i had with 250k miles on it changing the oil every 3k miles on my own and it never leaked.

Are the crush washers on Toyota's inferior?

Just asking.

Thanks!

 

Just the diffs. Well they are so cheap might as well...got these for nine bucks shipped...

 

Check that, I just researched and remembered my turd gen’s diffs, transfer case don’t have crush washers. Anybody want these?

 

Asked Toyota near me how much a gear oil change would be......$600 Jesus.....Found Toyota 75-90w gear oil at another dealership for $8.99 a quart, and they only had seven left....SCORE!!!!

 

It’s been 100,000 miles and over ten years since I’ve changed it......

 

Changing oil (engine, diffs, transfer, trans) on a short first interval is a good idea. All the new parts that the oil is lubricating will be breaking in and there will be a higher amount of very fine metal sluffed off as the rough edges get worn in which ends up in the oil and filter. Better to get it out of there than having it getting shoved through bearings for x thousand miles.

One property of gear oil os it’s ability to withstand and protect against the shear forces of gear teeth and bearing elements sliding past one another. Over time, this protection wears out and the metal parts wear directly on each other more and more (the oil starts to break down which causes more friction which causes the oil to break down more which causes more friction, etc etc.). Spending $ on changing the oil at the recommended intervals is less expensive than spending $$$$$ on having a tranny or gear box rebuilt, and way more convenient (and less embarrassing) than trying to get someone to tow your rig out of the middle of nowhere.