DIY: Differential Oil Drain & Fill

[Tundradrenalin]

Here’s what I did to drain and fill the differential gear oil (LSD) in my 2005 Tundra 4wd Access Cab. The process is basically the same for all models Toyota Trucks. This was a pretty simple process and knocked out two of them in under an hour with help from a fellow TSer BAD BONEZ BJ.

Tools Required:
Differential Gear Oil – SAE 90, 80w-90 or 75w-90 will do.
24mm Socket
Breaker Bar (optional)
Torque Wrench
Gloves
& a bunch of rags


Recommended Lube:



Preparation:
- Let the pumpkin cool down, hot oil isn’t much fun to get on your hands.
- Lay down something disposable, cardboard or something. Your old gear oil might smell very bad and can stain just about anything.





Step 1:
IMPORTANT, remove the FILL plug bolt first. Some oil will start to drain out.



Step 2:
- Remove the DRAIN plug bolt now.



- Let it all drain out.



Step 3:
- Jack up the driver’s side rear wheel so the differential drain hole is near parallel with the bottom of the pumpkin.
- This will allow the most oil to drain out from the base, where the most debris might be hiding out.



- This is a good time to clean the bolt plugs. The drain bolt has a magnet on the inside of it to capture larger pieces of worn gear shavings.
- Clean this off with some brake cleaner or the like.



Step 4:
- Replace the drain plug bolt (torque = 36 ft.lbs) and start filling the differential with oil. The gear oil bottles are conical enough to get the majority of the oil in there. Try getting about 2.5 – 3 quarts in there, then replace the fill plug bolt (torque = 36 ft.lbs).
- Take the truck out for a quick spin to disperse the oil within the gear housing.
Step 5:
- Repeat Step 1. Continue to fill the gear oil until you see the level of the oil inside the fill hole about leveled off with the bottom of the hole. Or just fill until you get some minor dribble like what you saw when you took the bolt off the first time.

- You may need the fluid pump, like we used here:


-Your filled rear diff should look like this on the inside:


- If you want to replace the crush washers, here are the Toyota Part#s. <LINK>
Front Transaxle –
Drain: 90430-24003 (copper flat washer/gasket)
Fill: 12157-10010 (metal crush washer/gasket)

Transfer Case –
Drain: 90430-18008 (aluminum crush washer/gasket)
Fill: 90430-18008 (aluminum crush washer/gasket)

Rear Differential –
Drain: 12157-10010 (metal crush washer/gasket)
Fill: 12157-10010 (metal crush washer/gasket)
(courtesy of TSer maxtorqe)

Good luck and have fun!


Reference post #1 from devinsixtyseven.
Reference post #2

[ddvk]

One correction to this process.. Thoroughly clean both bolt surfaces before doing gear oil changes. IT IS A MUST. Dirt injection can result in elevated wear numbers.

Looking at pic2 it looks pretty dirty, high chances of dirt injestion.

[Tundradrenalin]

Thanks man, I agree. The before and after of the bolt cleaning is pretty amazing and that step should NOT be skipped.

[HOGWILD]

Great post and my 06 DC used a 10MM hex socket for front Differential Fill plug and a 3/8" drive torque wrench! Just did my 30K and once again great post!! why the different washer on front diff drain? i will be working up different pump for the next time, i did not enjoy the slow cheap pep boys pump at all!

[Sigr6]

I just did this a few weeks ago with that same RP oil.

How often do you change yours? I think I read somewhere that it's 15k for rear dif and TC and 30k for front dif but i'm not sure.

[Tundradrenalin]

Originally Posted by Sigr6

I just did this a few weeks ago with that same RP oil.

How often do you change yours? I think I read somewhere that it's 15k for rear dif and TC and 30k for front dif but i'm not sure.

This was my first time changing the rear LSD. The truck has 27k+ miles now, so I'm probably going to make this a 30k interval even though RP says 50-100k. The '05 manual says replace limited slip diff oil every 30k, and it wasn't very hard anyways. And we all need excuses for more hands-on Tundra time!

Will be doing the front diff and t-case sometime real soon. blackmbj and I will attack both our trucks at the same time again.

[2XOverhead]

Great job!

The oil looked pretty dirty at 27k. I got about 75k on mine (10k by me). I don't know if mine has ever been changed so I'm going to change mine soon.

I noticed that half of your LSD has a hump on the right side, does '02s have the same LSD? Mine doesn't have the hump and I don't know if mine's a limited slip.

Again, great job.

BTW: nice sweatshirt.

[BamZipPow]

If you drop the spare tire a little, you should have enough room to tilt and squeeze the bottle into the fill hole...

[MtTrout]

A turkey baster works pretty well to top it off, just be sure and buy your own to avoid getting in trouble with your wife from stealing hers.

[MOREPOWER]

Good info I did it to my Tundra at 30k even used the same Royal Purple fluid looks like grape syrup. I'm going to keep doing it every 30k.

[imjin]

Thanks for the 6 gasket part #'s. They came in handy when the retarded parts counter guy at Haley Toyota not only told me that the fill plug on the front diff. didn't have a gasket, but he also didn't know what the transfer case was and couldn't tell from the exploded diagram that there was one. Even his buddy working behind him said the same thing, so I ended up leaving that day with just 3 gaskets; 1 for the front drain and 2 for the rear. Sometimes you just can't argue with stupid. I came back the next day armed with the part #'s and no explanation what they were for. I figured as little as I had to make him think, the better.

Just an FYI on the dealer, if you're in the Richmond area, avoid Haley Toyota like the plague. I don't let them touch my vehicles, but I will use their parts counter since it's near my house. Now I'm not sure that's even a good idea.

[shreve121764]

I just changed fluids in the front and rear differentials and the transfer case. I let each drain until I couldn't wait any longer, but still was not able to get the full amount in that the owners manual states. I put 3 quarts in the rear and it was already coming back out the fill hole, the manual states 3.7 quarts.

Can any of these three fluids (F&R diff and transfer case) be overfilled? Will overfilling cause any problems?

I was surprised that the fluid in the rear and transfer case looked new, with 31,000 miles. The front looked slightly darker, but still much better than I expected.

Very little metal dust on the magnets.

I used Lucas synthetic.

[Tundradrenalin]

Originally Posted by shreve121764

I just changed fluids in the front and rear differentials and the transfer case. I let each drain until I couldn't wait any longer, but still was not able to get the full amount in that the owners manual states. I put 3 quarts in the rear and it was already coming back out the fill hole, the manual states 3.7 quarts.

Can any of these three fluids (F&R diff and transfer case) be overfilled? Will overfilling cause any problems?

I was surprised that the fluid in the rear and transfer case looked new, with 31,000 miles. The front looked slightly darker, but still much better than I expected.

Very little metal dust on the magnets.

I used Lucas synthetic.

Sounds like you had a good gear oil change experience.
Did you jack up the axle as in Step#3 above? That should allow more to drain out.
How about the fill and test drive in Step#4? That would allow the oil to disperse throughout the housing.

About overfilling the gear oil. Normally the gears sit in a shallow bath of oil, so when action they spin through the pool and collect lube as they move. You would think that overfilling would mean more oil to go through and thereby creating more resistance. More resistance would essentially reduce the effeciency of the gears. But since the fill hole is set at the position it is, instead of being above the housing, it creates an overflow port. So overfilling while at an even ground level should be avoided automatically.

[kathyricks]

Originally Posted by shreve121764

Can any of these three fluids (F&R diff and transfer case) be overfilled? Will overfilling cause any problems?

Yes and that's why I think the flll plugs should be installed loosely so you can drive the truck around the block, then park it on a level surface, crawl under the truck and do one final check of the gear oil level before final tightening of the fill plugs.

Overfilling any drivetrain component can lead to foaming of the lube or damage to seals and a permanent leak. That's why ALL carmakers strongly advise against overfilling any componet.

[papayasalad2002]

Nice post. I used this today...changed out my rear differential fluid... it sure was pretty nasty! The overfilling info is useful...I'll double check tomorrow to make sure that baby wasn't overfilled. Thanks.l