Changing differential fluid

[John Staton]

So I have not changed diff fluid this on my truck since I got it, but since I got stuck this morning and my backend was underwater for over an hour while I waited for my son to come winch me out I figured maybe it was time. I did a search and there are no threads on it. A few questions:

1. any preferences on type of fluid?
2. Tips and tricks or things to watch out for? just a drain and fill deal right?
3. I usually get my FSM pages from posts and have never downloaded a copy. I thought I would be able to locate where they are on here, but was unable. Can someone point me in the right direction?

Pic for your entertainment. I have been through this hole many times and typically have no problem goosing my way through. This morning I neglected to get out of the truck and lock my hubs so I got stuck in 2WD thinking I was in 4WD. In the 5 years I have had this truck it was the second time for me to get stuck and both times it was in this hole. First time used the John Deere to pull me out but this time I called my son who purchased his first Toyota from a Mud member this year (97 4Runner, stick, with a winch). He was happy to come pull Dad out and give me a hard time.

 

[4runner2FJ60]

Nice rig! Its not a big deal. I would recommend running it around a bit first to warm things up like your engine for oil change. Pull both plugs and wait....maintain flat ground if possible. Reinstall with new gaskets and fill with a hand pump until it starts to come out top hole. Pretty simple.

Optional get allen head drain plug in case you ever scrape across a rock or other....

 

[John Staton]

Nice rig! Its not a big deal. I would recommend running it around a bit first to warm things up like your engine for oil change. Pull both plugs and wait....maintain flat ground if possible. Reinstall with new gaskets and fill with a hand pump until it starts to come out top hole. Pretty simple.

Optional get allen head drain plug in case you ever scrape across a rock or other....

Gaskets?? guess I need to order a couple. Any recommendations on fluid?? and I have a pump from when I changed my transmission and transfer fluid after my H55 upgrade I can use. From what I understood is a drain plug on the bottom and a fill plug on the top. I have not looked yet....need to clean up some mud first.

 

[MDH33]

Make sure your fill plug comes off before you pull the drain plug.

I drain and fill my Trans and tc at the same time I do diffs, so I just get a 5 gallon bucket of 90w, nothing fancy. Fill till they just overflow the fill hole.

a good 5 gallon bucket lid pump with a long hose is worth every penny.

Good call on the new fiber gaskets. I always need some but the auto stores never have the right size. Need to see if I can buy a bunch from Toyota next time I order something.

 

[4runner2FJ60]

Yes I think mine was 90w CarQuest - Advanced Auto brand. agree on fill plug 1st....it also helps to drain faster. It is the bolt looking thing on the front or back of diff depending on if your doing front axle or back. Drain is on bottom of course. More comes out than you would think so be ready......

 

[diesellibrarian]

There seems to be a couple of different FSMs floating around. This Body/Chassis manual has lots of great info, obviously, but doesn't seem to have the maintenance schedules etc. Here's a screencap from the "Maintenance" section of the other manual that I have.

 

[2mbb]

The differentials use a folded steel gasket

 

[John Staton]

Thanks...I upgraded to an H55 and had my transfer case rebuilt so I have low profile plugs on those and just ordered similar ones for both my diffs from Wits end along with the gaskets. From the comments it looks like you use the same oil in transmission, transfer case AND differentials?? I am guessing folks have the strongest opinion about what is used in the transfer case so was looking for guidance on what to buy for fluid based on changing all three at the same time. And any guesstimate on how much I would need for all three applications?

 

[Godwin]

The differentials use a folded steel gasket

View attachment 3216510

^^this. Steel on steel for the diff and transmission fill and drain plugs.

 

[Godwin]

Thanks...I upgraded to an H55 and had my transfer case rebuilt so I have low profile plugs on those and just ordered similar ones for both my diffs from Wits end along with the gaskets. From the comments it looks like you use the same oil in transmission, transfer case AND differentials?? I am guessing folks have the strongest opinion about what is used in the transfer case so was looking for guidance on what to buy for fluid based on changing all three at the same time. And any guesstimate on how much I would need for all three applications?

GL 4 for the transmission because of the material of the synchronizers, GL 5 in the transfer case and diffs.

 

[OSS]

Regular ole Sta-lube 80W-90 GL5 gear oil is fine

 

[John Staton]

Regular ole Sta-lube 80W-90 GL5 gear oil is fine

for everything....transmission, transfer and diffs?

 

[2mbb]

There is a 1986 maintenance manual in the resources tab (top of the page). As was probably the case in the 1980's there is no recommended replacement interval of these drivetrain lubricants for "normal conditions". However, the "severe condition" application recommends replacement every 15,000 miles. The examples of severe conditions don't seem so severe. Nothing about being stuck in a mud puddle!

 

[John Staton]

There is a 1986 maintenance manual in the resources tab (top of the page. As was probably the case in the 1980's there is no recommended replacement interval of these drivetrain lubricants for "normal conditions". However, the "severe condition" application recommends replacement every 15,000 miles. The examples of severe conditions don't seem so severe. Nothing about being stuck in a mud puddle!



View attachment 3216566

View attachment 3216569

View attachment 3216570

good info, and hey, that was a big mud puddle, lol. In all seriousness, I have never changed it and dont know when it was changed before I got the truck so just something I have thought about doing. Using getting stuck as my motivator. What I need to do is order that new front bumper from trail-trailor and get that winch I have been thinking about for a while now. Need to see how mean uncle sam is gonna be to me this year first.

 

[cps432]

for everything....transmission, transfer and diffs?

You can use gl-5 in the transmission and it will be okay. However, it is a fact that there is an additive in the gl-5 that bonds to brass stronger than brass molecules bond to themselves. Theoretically, and I’m sure in many real world scenarios, the brass syncros in the transmission can wear out faster. This degradation happens on a molecular level and it’s only when the friction between the additive bonded brass molecules is greater than the molecular bond of the brass/brass molecules.

In short, put gl-4 in there like Toyota suggests. If you don’t have any gl-5 will work just fine. If you run 5 in there for a long long time I imagine the synchros will be worn slightly more than if you ran 4. It won’t cause catastrophe. It’s not like you’re running a race engine through that transmission.

 

[g-man]

That's a good idea to check the gear oil now. I mean, if the seals were bad your going to have water mixed in there and milky gear oil.

While your down there check your breather valves. They are on a short piece of hose that comes off the axle housing and mounts up on the frame. They can get stuck. Spray some lube in the valves and work them by hand to make sure the springs are lubricated and things are moving.

Get a hand pump for putting the gear oil in. Believe me it's messy trying to use a sqeeze bottle and refill it from a gallon or 5 quart bottle. A pump with several feet of hose on each side. One goes in the gear oil jug the other end in the fill hole. When it starts to roll out of the fill hole your done. Don't bother stopping to check with you finger it's just messy and slows everything down. Have some scrap cardboard to catch overflow, plenty of rags and some nitrile gloves.

 

[John Staton]

That's a good idea to check the gear oil now. I mean, if the seals were bad your going to have water mixed in there and milky gear oil.

While your down there check your breather valves. They are on a short piece of hose that comes off the axle housing and mounts up on the frame. They can get stuck. Spray some lube in the valves and work them by hand to make sure the springs are lubricated and things are moving.

Get a hand pump for putting the gear oil in. Believe me it's messy trying to use a sqeeze bottle and refill it from a gallon or 5 quart bottle. A pump with several feet of hose on each side. One goes in the gear oil jug the other end in the fill hole. When it starts to roll out of the fill hole your done. Don't bother stopping to check with you finger it's just messy and slows everything down. Have some scrap cardboard to catch overflow, plenty of rags and some nitrile gloves.

Thanks...I bought a nice pump refill setup as I changed my fluids after the break in of my H55 some time back. Sorry for all the newbie questions, but I am looking for one fluid for diffs, transfer and transmission and changing them all at once.....and from what you said maybe I just go GL4, something like Sta Lube GL-4 or my son uses this Redline that is GL4 for his '97 4Runner (stick) but it is about 40% more expensive:

Looks like I would need 3 gallons to do all three jobs. I will have to research the breather valves. My son recently bought a 97 4Runner from a mud member and bought a kit to extend his breathers for creek crossings and I read somewhere that mine already has something similar, though not as long. Thanks for the input.

 

[OSS]

and from what you said maybe I just go GL4, something like Sta Lube GL-4

The Toyota manual states that the transmission can take a GL-4 or GL-5 gear oil …. but the differentials must use a GL-5 oil. Do not use a GL-4 oil in the differentials.

If I recall- decades ago, Sta-Lube’s ubiquitous gear oil that was found at every auto parts store had a label that said GL4 and GL5. That’s no longer the case and they no longer make that oil. So my Sta-Lube recommendation above is no longer valid.

 

[John Staton]

The Toyota manual states that the transmission can take a GL-4 or GL-5 gear oil …. but the differentials must use a GL-5 oil. Do not use a GL-4 oil in the differentials.

If I recall- decades ago, Sta-Lube’s ubiquitous gear oil that was found at every auto parts store had a label that said GL4 and GL5. That’s no longer the case and they no longer make that oil. So my Sta-Lube recommendation above is no longer valid.

thanks for the clarification...reading back I see the FSM reads transmission/transfer is GL-5 or 4, but differential needs to be GL-5 so looks like this would do for my one for everything:

 

[John Staton]

doing this over the weekend along with power steering fluid change. Should I worry about a torque setting for my differential, transmission or transfer case plugs....or just snug them up like I do when I change my oil??