DIY Transfer Case Fluid Change How-To (4 Viewers)

Cypher

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A few weeks ago I decided it was time to change the transfer case (T-case) fluid and starting doing a bunch of research here on Mud. I found lots of good info in lots of different threads so I thought I would document the work and put everything into one thread. It is definitely a super easy quick one :banana: job. The longest part of the process was waiting for the T-case to drain completely. From start to finish, I was done in 30 minutes including clean-up.

Most of the folks on Mud have replaced the fluid with full synthetic. The most popular seem to be Mobile1, Royal Purple, and Amsoil. A few have used the Amsoil Heavy Gear Oil as they tow on a regular basis. Choosing any of the well known name brands is a safe bet. A fluid hand pump will make the job much easier but the T-case can be done with the standard squeeze bottles. Some Cruiser owners have mentioned the synthetic fluid helps alleviate the gear whine that often comes from the T-case of Cruisers on a cold morning.

Here is what you need:
- 1.4 quarts of Gear Oil GL-5 75W-90
- Fill/Drain plug gaskets/washers which are a couple of bucks each from Toyota (part number: 90430-18008). These are not required and the old ones can be reused of they are still in good shape.
- Latex or similar protective gloves (if you have ever smelt old gear oil, you know that you DO NOT want to get this stuff on your hands)
- 24mm or 7/8in socket/wrench
- 12mm socket/wrench
- Paper or shop towels
- Drain pan (not pictured)
- Torque wrench (not pictured)


PB240123.JPG





It is suggested to drive your Cruiser around a bit before the replacing the fluid. This will warm up the fluid and help in the process of draining the T-case. Park your truck on level ground to ensure proper drain and fill. As with anytime you are going to get under a vehicle, take all the required safety measures and precautions such as using wheel chocks and using the emergency brake. It is a good idea to clean of any loose dirt and grime from the fill and drain plugs before you start. It is important to not introduce any foreign material into the T-case.

If your Cruiser is equipped with the factory T-case skid (or aftermarket skid) remove this first with the 12mm socket for ease of draining. For those who may not be familiar with the T-Case, it is the the center gear box, on the driver's side of the transmission, that the front and rear drive shafts are connected to.

PB240120_modified.jpg




Remove the fill plug with a 24mm socket. This is important since you do not want to drain the T-case and then not be able to get the fill plug off (rule of thumb for all fluid changes).

Position your drain pan under the drain plug and slightly to the rear of the vehicle, the fluid comes out fast and will overshoot your pan if you are not ready for it. Remove the drain plug with a 24mm socket. Do not confuse the drain plug with the fill plug. Take note of the differences as indicated in the picture below (D = Drain Plug, F = Fill Plug).


PB240124.JPG



PB240125.JPG




Let the fluid completely drain from the T-case.

While the fluid is draining this is a good chance to clean up the drain plug. You will most likely notice a small amount of metal shavings on the magnet the drain plug is equipped with. A small amount of shavings is normal wear. If you have lots, it is recommended you get your T-case checked out.


PB240127.JPG



Replace the drain plug with a new plug gasket. Again be sure the plug is clean before replacing. It is not a bad idea to ensure there is a little gear oil on the threads of the plug. Torque the drain plug to 27ft/lbs. It is extremely important to not over tighten the plugs! You will crack the T-case…

Fill the T-case with 1.4 quarts of fluid or until the fluid begins to come out of the fill location. If the vehicle is not parked on level ground, it is recommended that you at least ensure that you get 1.4 quarts into the T-case.

Replace the fill plug with a new plug gasket. Again be sure the plug is clean before replacing. It is not a bad idea to ensure there is a little gear oil on the threads of the plug. Torque the drain plug to 27ft/lbs. It is extremely important to not over tighten the plugs! You will crack the T-case…

Finally, replace your skid plate and you are done!

Now take your old gear oil to a location that can properly dispose it such as Autozone, Checkers, O’Riley, or the like and take pride in some DIY Cruiser maintenance. FYI, gear oil can be mixed with engine oil and recycled at the same time.

If I missed something or you have a good tip to add, post up!
 
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rusty_tlc

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The "gaskets" are more correctly referred to as washers. It the olden days they were designed to crush when tightened and were not re-usable. I believe the aluminum ones you picture can be re-used as long as they are in good shape.
 
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Nice write up and pictures. Thanks.

The case drains fine without the skid plate removed although you may have to wipe a little oil off of it at the end.

I don't think there is any reason to measure the fluid added as the case cannot be overfilled. Full is where the oil drains out of the fill hole (is level with the bottom of the hole).

Enviro note : Used gear oil can be mixed and recycled with used engine oil.

Practical note: Since you will smell of gear oil (sulfur based antiwear additives are what smell) and so will the garage you might as well do the diffs at the same time.
 

Copenhagen1

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Practical note: Since you will smell of gear oil (sulfur based antiwear additives are what smell) and so will the garage you might as well do the diffs at the same time.

Do the diffs use the exact same gear oil? If so, how much do they hold and is there any other additives that need to go in there?

I am being lazy. I know this has probably been covered before but as long as you brought it up.....:D
 

Cypher

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The "gaskets" are more correctly referred to as washers. It the olden days they were designed to crush when tightened and were not re-usable. I believe the aluminum ones you picture can be re-used as long as they are in good shape.

Yes you are correct. I have added a note about this in the parts needed section. Thanks!

It's no big deal if that happens. Just flip the truck over and the drain becomes the fill hole. :)

Great write-up!

Thanks! And yes, flipping the truck over would make the drain plug into a fill plug HAHA! :lol:

Nice write up and pictures. Thanks.

The case drains fine without the skid plate removed although you may have to wipe a little oil off of it at the end.

I don't think there is any reason to measure the fluid added as the case cannot be overfilled. Full is where the oil drains out of the fill hole (is level with the bottom of the hole).

Enviro note : Used gear oil can be mixed and recycled with used engine oil.

Practical note: Since you will smell of gear oil (sulfur based antiwear additives are what smell) and so will the garage you might as well do the diffs at the same time.

Nice! Good to know gear oil can be mixed with engine oil and taken at the same time to be recycled. I have added this to the write-up.
 
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Thanks for the great write up and pictures Cypher.

The fluid in the hundy's t-case was recently changed when it was in for service earlier in the year, but next time this post is going to come in real handy.
 
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Do the diffs use the exact same gear oil? If so, how much do they hold and is there any other additives that need to go in there?

I am being lazy. I know this has probably been covered before but as long as you brought it up.....:D


Yes, it's the same gear lube.

The exact amounts are in your owner's manual (back).

IIRC, it's about 5-6 quarts total, for the front and rear diffs.

No additional additives are needed, but you can add some lucas in there if you want.

I did my XF Case and diffs at once, I did a mix of ~30% Royal Purple and 70~ Mobil1 in each. I think I got 8 quarts total, and had a little M1 left over...

I also did a drain/refill on the Trans (about 6-quarts), an oil change, and greased the driveshafts while I was under there and had the skid plates off.
 

TheFuzz

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IIRC, we have a how-to for the diffs and tranny in the FAQ but there isn't a writeup on the t-case in there yet. This needs to be added! Thanks for the great write up.
 

Cypher

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IIRC, we have a how-to for the diffs and tranny in the FAQ but there isn't a writeup on the t-case in there yet. This needs to be added! Thanks for the great write up.

Thanks Fuzz! True, I was not able to find a t-case how-to in my research across the forums and thus the reason I created this one. There is lots of good info out there in lots of different threads, just not in all one spot.
 
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Thanks

Doing this tomorrow. Nice,neat and precise. Thanks

After doing a little research I want to use the royal purple product and three hours later I'm more confused than I was before. Is it okay to use the http://www.royalpurple.com/gear-oil.html (max gear) for all three componets or just for the front and rear diffs. And use the http://www.royalpurple.com/manual-transmission-fluid.html (Synchromax) for the transfer case?

Ive searched and read for three hours and havnt come to a definitive conclusion.

Thanks for any input.

-Girl
 
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CharlieS

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Another trick for filling is to use a long hose and let gravity fill it. I have a length of clear hose that I picked up at the hardware store that I keep aside for just this purpose. I use a 6' step ladder placed beside the vehicle, and a coat hanger hook to hold the bottle upside down toward top of the ladder (higher than the fill port on whatever you are trying to fill - diff/trans/etc). One end of the hose goes on the nipple on the quart bottle (hose is sized for a friction fit on the nipple) and the other end goes into the fill hole on the trans/diff/etc. I puncture the base of the bottle and walk away (have a #6 as they say on the 80 forum). It works like a charm and is not fuss, no mess...
 

Cypher

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Doing this tomorrow. Nice,neat and precise. Thanks

After doing a little research I want to use the royal purple product and three hours later I'm more confused than I was before. Is it okay to use the Royal Purple Gear Oil (max gear) for all three componets or just for the front and rear diffs. And use the Royal Purple Manual Transmission Fluid (Synchromax) for the transfer case?

Ive searched and read for three hours and havnt come to a definitive conclusion.

Thanks for any input.

-Girl

You're welcome! Thanks for posting up...

Based on my research, you are safe going with the gear oil in the front/rear diffs and t-case. However, it does sound like the Synchromax is good stuff and specifically calls out the t-case which is nice. Based on some quick searches, the Synchromax seems to be a few greenies more expensive than the gear oil but nothing to fret over. I say give it a try and let us know what you think!

Another trick for filling is to use a long hose and let gravity fill it. I have a length of clear hose that I picked up at the hardware store that I keep aside for just this purpose. I use a 6' step ladder placed beside the vehicle, and a coat hanger hook to hold the bottle upside down toward top of the ladder (higher than the fill port on whatever you are trying to fill - diff/trans/etc). One end of the hose goes on the nipple on the quart bottle (hose is sized for a friction fit on the nipple) and the other end goes into the fill hole on the trans/diff/etc. I puncture the base of the bottle and walk away (have a #6 as they say on the 80 forum). It works like a charm and is not fuss, no mess...

You can always count on gravity... Nicely done and great suggestion!
 

TheFuzz

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Why the hell is this thread not stickied yet?

Tons of great info here. I've PMed the appropriate people, I guess they are still on a holiday getaway...:D
 
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Soo I went ahead and changed every thing this morning. I ended up putting the Synchromax in the transfer case... I guess this was a no no lol. I was checking my e-mail and got this from Royal purple rep.

Good morning Mr. Riley



We recommend Royal Purple Max Gear 75W-90 (part #01300, quart bottle) for your front & rear differential (you do not need to add any limited slip additive), and your transfer case.



Synchromax is not recommended for your Land Cruiser. Synchromax is a lighter viscosity fluid used for transfer cases and manual transmissions which require a lighter viscosity oil.



The capacities you need for your 2004 Land Cruiser are;



Diff. front: 1.7 quarts

Diff. rear: 3.5 quarts

Transfer case: 1.35 quarts



The total Max Gear 75W-90 you need is 6.55 quarts.

Guess i jumped the gun a lil. I'll be changing it out tomorrow morning. Hope i didnt fark anything up.
 

TheFuzz

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I'm sure you're ok for the short term. As long as you change it out tomorrow I cant possibly see what damage could be done by running syncromax for 24 hours. Good information to know though, especially the capacities.
 

Cypher

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Good to know! Glad that the Royal Purple support guys got back to you. That really says something about them. There are not many companies these days that care enough to get back to a potential customer that quickly.
 
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Thanks for the great write up. Just completed the fluid change. I had to use a syringe to get the new fluids in because I didn't want to take down my Slee belly plate. With the info in this write up, everything went smoothly, though it took me about 60min instead of 30.

Thanks!
 

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