check your differential fluid!!!!

[underthehood]

so, i was installing my INCHWORM E-LOCKER COVER today and decided to check my diff. fluid. it was BLACK and had slight metal shavings on the drain plug. also slight metal glint in the fluid. only 6500 miles on it with some hard wheeling and diff lock conditions. all i can do is hope for the best, but i know some new 75w-140 synthetic valvoline oil will help. P.S. i would not count on the Jiffy Lubes of the world to be checking this for you. do it yourself. 15/16 wrench or socket is all you need. i am interested to know if mine is an isolated case or if my fellow cruisers are having the same issues. and yes i do know all about the rear diff problems(breaking gears) maybe this is a precursor. like i said all i can do is wait and see.

[Stinkyfinger]

I switched all the diffs ,transfer and mt transmission fluid to synthetic oil at 18,000 miles. The front diff, transfer and transmission oil still looked brand new, but like you when I drained the rear axle it was black. I've changed out the diff oil before on other Toyota trucks at 70000 and 80000 miles and it would still looked like new oil.
I've never seen diff oil get that black. It would take excessive heat to darken the oil like that so soon, which could be adding to the problem of the rear gears breaking because they weren't heat treat right.
I'm all wheel drive, so I pretty much have the same power going to the front and rear almost all the time. So for the front to be fine and the rear to change like that would indicate that the rear gears were assembled to tight, causing excessive heat that would brake down the oil.
Since I've changed to synthetic 10,000 miles ago I've been periodically checking the fluid in the rear and it's still looks good. I think all of the heat and shavings were created during the first 1000 miles of break in.
I'm not worried about it because the synthetic oil made a huge difference in driving and mpg, and a set of 4.56 gears will be one of my next mods, hopefully in the next year or so.

[tddfj]

great info will be checking asap and inform the mdealer about what i find. have not done a lot of offroading but have put under a load towing a few times.

[tddfj]

just checked my rear diff oil. it is a real dark color. any one know what the oe oil should look like?

[LandCruisers4Life]

All your fluids should be changed after a few thousand miles. This crud you see is because the stuff is breaking in. I plan to keep using regular Castrol in mine until 20,000 miles and then switch to synthetic. Same with the gear oils. Use regular gear oils until 20,000 and switch to the good stuff. All the crud should have been worked out by then.

[underthehood]

does that STINKYFINGER come with a ''reach around"? ha ha just kidding. thats a great handle. thanx for the info. mine is the auto trans. sounds like synthetic oil is the key along with getting rid of the nasty oil due to break in. i know its not normal for diffs to break in like that but maybe with fresh oil the gears will stop wearing each other out so fast. its hard to believe that you get better gas mileage, but hey anything helps with these gas guzzlers.

[saskdiesel]

This is normal.
Change it if you want but its not a pressing need.
Whenever you check the diff magnet it will have metal stuck to it.

[Stinkyfinger]

The metal shavings are normal the pitch black color is not
I've changed the original diff oil on previous vehicles at 70,000 miles it had shavings in it, but it still looked like new oil. I have never seen diff oil turn that black. I thought maybe it was a special oil for break in, but the front diff and transfer oil looked brand new.
On a side note I gained 1.4 mpg switching to synthetic. I switched to royal purple about 5 months ago and I am still averaging 1.4 mpg more. The large gain might be because I'm all wheel drive(more moving parts), but you can never go wrong switching to synthetic.

[PhilC64]

Pardon the cut and paste but here is what I did.

1. Drive truck until fully warm.
2. Remove the fill and drain plugs with a six-point 24mm socket, catching fluid in a suitable container. Let it drain for a long time, gear oil is viscous.
3. Replace drain plug, using a new washer. Torque to 36 ft. lbs.
4. Pump or squeeze new Hypoid gear oil into fill hole until it runs out the bottom of the hole. It will take about 3 quarts, a little more if you don't have the locking diff.
5. Replace fill plug, using a new washer. Torque to 36 ft. lbs.

Any API GL-5 Hypoid gear oil will work. I used Valvoline Synthetic 75w 90 but Mobil 1 75w-90 is also good.

Here is the page from the service manual.

[gaylonw]

I am sitting at the Toyota Store and I had them do a 4x4 Service as a result of this post.
The rear fluid was really dirty with Metal on the plug. Some of the debri was 1/2" long shavenings.
The front dif was better. (This is an Auto so you might expect that because most of the miles are 2x not 4x4.)
The transfer case oil looked new.
They also changed my armrests under warranty because the material is getting little fuz balls on it.

I would not wait till 30K to do the 4x4 service if I were you..............gm

[fjteddy]

Im at 44 000km the oil is still nice no shavings, good trail ride but will be going on synt at 48 000km.

[ATTILLA]

Worst filthiest rear axle gear oil I have ever seen, and at only 29k, several long slivers as well, black and stinky (no offense stinkyfinger), switched to synthetic and will replace every 6k until it is perfectly clean.... Toyota definitely has an issue here, IMHO.

[Stinkyfinger]

I wouldn't worry about switching every 6k.
I've run for 15K since switching to synthetic and the oil still looks good.
The purpose of running synthetic is better lubrication, but more importantly longevity.
I'll probably change mine when I hit 50,000 or 60,000 miles only because I do a lot of mudding and water crossings in the spring time.
Keep in mind any damage to the rear was already done during break in, so changing the oil more often won't help now

[ATTILLA]

Originally Posted by Stinkyfinger

I wouldn't worry about switching every 6k.
I've run for 15K since switching to synthetic and the oil still looks good.
The purpose of running synthetic is better lubrication, but more importantly longevity.
I'll probably change mine when I hit 50,000 or 60,000 miles only because I do a lot of mudding and water crossings in the spring time.
Keep in mind any damage to the rear was already done during break in, so changing the oil more often won't help now

It'll be just to get whatever I didn't get out of there the first time, you know how that heavy oil makes everything cling, it'll merely be another flush of the breakin metals...

[ckline]

I changed my rear diff yesterday and didn't notice any shavings. Figured I would because of trail time, but happy I didn't. It was filthy, but that was about it. I changed the MT gear fluid as well. I drive an 07' so they didn't put the synthetic in that model. In one day, I can feel its easier to shift. Don't know if it just because I changed it and I want it to feel smoother, or if it actually is smoother. I'm gonna hit the transfer case tomorrow and the front diff. When I was looking at the front diff though, it looked like the drain and fill was an allen wrench. AM I LOOKING IN THE WRONG PLACE? I kinda think I am, but I can't find a diagram of what the front looks like. Figured it would look the same as the rear, but I couldn't see it.

[ckline]

Originally Posted by underthehood

do it yourself. 15/16 wrench or socket is all you need. i am interested to know if mine is an isolated case or if my fellow cruisers are having the same issues. and yes i do know all about the rear diff problems(breaking gears) maybe this is a precursor. like i said all i can do is wait and see.

Also may want to pick up a 10mm Allen Wrench for the front diff. 15/16 is for the rear. Just checked with my Tech and I am looking in the right place. Maybe its different in the 08'?

[FirstToy]

whoa guys, lets not panic. I noticed this with the 4Runners as well. For some reason, the rear diff gets dark but I feel this is a normal condition and don't worry about it. In every Toyota 8" rear diff i've seen, the rear diff oil is dark even with few miles on it.
I would say to change it more often if it bothers you but I am not convinced there is anything wrong...

maybe someone can shed a bit of light on the matter but don't panic just yet

[ckline]

Originally Posted by FirstToy

whoa guys, lets not panic. I noticed this with the 4Runners as well.

For sure nothing to worry about because it is a Toyota. Going into the dealership and them letting me know how easy it was to do it myself...they suggested that if driven hard to change every 30k miles. I don't think they were just saying that, because they knew I wasn't gonna pay them to do it. Just the life blood of the truck, so its prolly a good idea to change it. With that said, I'm gonna have a booger of a time with the front diff. I stripped the allen bolt

[kp66]

Well finally got into my dealership today for the diff oil change. They told me to come back at 60 000KM
i said no thanks i have 24 000 km on my fj now and i want it changed to synthetic. So i asked for the service manager and told him what i wanted he said no need the oil in your diff will still look like new come back at 60k so i said i bet you my service bill its black as coal lol. He said cant do it but will swing something.
Well i did oil + filter, diff oil to synthoetic and tire rotation bill was $125.

MY DIFF OIL WAS BLACK LIKE COAL AND MY TRUCK HAS NOT SEEN DIRT YET. (24 000 KM)
I got a free TRD hat $35 LOL

SO ALL YOU BEST GET THE DIFF OIL CHANGED.

TO ALL THAT GOT THIS THREAD GOIN ME AN MY REAR DIFF THANK YOU ALL.

[NCCruiser302]

Yikes! The new FJ just hit 20,000 miles, I think I'll take a look at the rear diff this afternoon. What's the best type of synthetic to put in it?

I'm especially concerned because my '87 60's rear diff is almost stripped, looks like the work of severe grinding, and I'm an easy driver. Maybe the engineers at toyota like tight rear ends

[NoHandleBars]

I changed mine out to RP Gear Oil at I believe 10k? And at 10k it was very dirty, I'd imagine people going up to 18-20k are running some high-risk of premature wear\damage.

[XDodgeFJ2]

Crap-never checked the first one, flipped it on a bridge overpass @33k doing 70, but it never complained-lots of mud in its past, just like the present one.That incident is the reason I BOUGHT A 2ND ONE, as the crash involved 3 guard rail impacts, with a 47'(state police measured)flight and inverted landing(rear pillars remained intact, and I walked with stiches and staples)-lotsa rain.Just checked my rear third member fluid....UGLY. Will flush and replace-though this IS the one that sees the constant force applied function, but, oil spotting on towels left lots of metal.... but, I got faith(thats the reason I mentioned the crash) and suspect that is mostly break in metal, and the dark color is temp induced.Anybody done the 4:56 thing with the same results?3:73 probably puts a higher concentration
of as$ to the metal, especially if you've slapped bigger rolling stock aboard.Mine is currently @ 16k-but it has been pushing 35" tires and has seen lotsa mud(high temps accordingly)so what looks ugly may be just usage and stock fluid reaction to force and temperature.More money going to royal purple prods.....

[NoHandleBars]

Originally Posted by XDodgeFJ2

****-never checked the first one, flipped it on a bridge overpass @33k doing 70, but it never complained-lots of mud in its past, just like the present one.That incident is the reason I BOUGHT A 2ND ONE, as the crash involved 3 guard rail impacts, with a 47'(state police measured)flight and inverted landing(rear pillars remained intact, and I walked with stiches and staples)-lotsa rain.Just checked my rear third member fluid....UGLY. Will flush and replace-though this IS the one that sees the constant force applied function, but, oil spotting on towels left lots of metal.... but, I got faith(thats the reason I mentioned the crash) and suspect that is mostly break in metal, and the dark color is temp induced.Anybody done the 4:56 thing with the same results?3:73 probably puts a higher concentration
of as$ to the metal, especially if you've slapped bigger rolling stock aboard.Mine is currently @ 16k-but it has been pushing 35" tires and has seen lotsa mud(high temps accordingly)so what looks ugly may be just usage and stock fluid reaction to force and temperature.More money going to royal purple prods.....

Wow. Thanks for the life story. :-P

[joebob2586]

just changed out my front and rear diffs to royal purple at 13500 miles both front and rear diffs had black fliud with shavings in it. Supposedly royal purple will also decrease the running temp of the gears...we will see.

[NoHandleBars]

Originally Posted by joebob2586

just changed out my front and rear diffs to royal purple at 13500 miles both front and rear diffs had black fliud with shavings in it. Supposedly royal purple will also decrease the running temp of the gears...we will see.

RP has kick A$$ gear oil. When I changed mine out I instantly noticed a difference. I'm going to assume you have a manual if your front differential had black fluid in it.

[Niner]

Originally Posted by NoHandleBars

RP has kick A$$ gear oil. When I changed mine out I instantly noticed a difference. I'm going to assume you have a manual if your front differential had black fluid in it.

Front diff spins all the time on both the AT and MT since the CV shafts are always turning with the wheels