Front Diff and Transfer Case Oil Change Howto

@jspadaro hows the mobil 1 helped?

 

Just got an 07 Tacoma and plan on doing this fluid drain this weekend. Thanks for the post

 

Lets say a fellow was feeling lazy (and didn't have a 10 mm hex) and only drained the fluid out of the front and rear diff (using a 24 mm socket).

1.) Are the front diff and transfer case 'connected'?
2.) Do the front diff and transfer case use the same fluid? (75w90)
3.) Is it "worth doing" if you only do the front and rear differentials (because, as mentioned, you don't have the tools/time to remove the skidplate and the 10 mm hex fill/drain plugs)?

I guess I'm a little confused about the relationship between front diff and transfer case....thanks for enlightening. I got under my '06 TRD Sport and was expecting to find the 10 mm bolts, but couldn't find them. I think they're under the skid plate, but (dumb question) < i'm pretty sure I don't have a skid plate??

 

1) only by the drive shaft, no fluid exchange
2) yes
3) worth doing? depends if it needs it or not.

the transfer case is on the back of the transmission, and splits the drive to a rear and front drive shaft, and has the low range reduction gears in it too.

standard RWD setup:


4WD setup

the red thing is the transfer case, the yellow is the front differential and drive shafts.

these pics aren't toyota specific, but apply to all conventional drives.

 

Thanks for the explanations, Leftcoast.

Another question: Any recommendation on a conventional (dino, non-synthetic) oil to use in an '06 with mechanical LSD? Sounds like they (mechanical LSD's) don't like the synthetics....Mobil1 sounds like a common choice, but not sure if the mechanical vs. e-brake has an impact on which dino oil to use.

 

I thought it was the automatic LSDs like ford 'positraction' that didn't like some synthetics. I'm using redline in mine, have had no problems to date.

 

Is it Better to change the diff/transfer case oil when engine (and tranny) are hot? If so, what kind of driving would be a good way to "gently" warm them up? Hills better than flat driving?

 

warm oil drains faster and more complete, take for a 20 min drive and change it after

if too hot, then wait for it to cool off

 

T55 is also the size of the bed mount bolts, so you can get more than one use out of it. I found that out when adding another set of D-Rings to the front of the bed.

I slightly stripped my drain plug about a year ago when I tightened the plug after a change. I picked up a spare drain plug off Amazon which came in handy yesterday when installing the ECGS bushing. Old plug was completely rounded off and nothing I had was sticking in it. Ended up having to use a blue wrench, hammer, and chisel to get the old plug moving.

Shitty design with crappy pot metal on a plug that is torqued over 40 pounds. I damn near rounded off the new one and that was only getting to about 30 pounds of torque.

Remains of the old plug:

 

I just did my 3rd diff oil change (90k). These threads always help and I keep referring back to them when I do maintenance to check torques and what not. While draining the rear and front diffs I looked at the gears and saw something concerning. There is rust forming. It isn't forming on the contact surface of the teeth but it still concerns me.

I don't do water crossings. Could it be from condensing moisture forming inside? I tried to look around the web and found that this happens. Not sure why.

 

I wouldn't worry about it...Also, that fluid coming out looks pretty clean. I changed mine at 30,000 a few times and the fluid coming out was clean too. I'm now waiting until closer to 50,000 to change it out from now on.

 

Interesting as that is the drain and many of those parts would be under the gear oil. I looked at mine on Friday and everything was bright and clean inside. The surface rust probably won't kill anything though.

How often do you use or "exercise" your front diff?

 

I'd say about 10%

 

I did the transfer case a long time ago and the fluid was just fine and dandy, I also did the rear diff and it was just fine as well. Anyways I am working on the front diff rn and I have gotten the fill plug loose but cannot get the drain plug free. I have soaked it multiple times w/ PB and "tapped" it a couple times with a ball peen but all I have done is begun to strip it. I still have some grip on it but it just will not break free. What should be my next move? thanks for the help

 

I ended up having to use a torx bit with an impact gun. Don't quote me but I think it's T55

 

The previously mentioned impact and T55 may work. If you haven't rounded it out completely and all you have is simple hand tools, try some heat before going back to your methods I use a torch on just about everything. Don't burn your house or your truck down though.

If you have rounded it out completely, you can get it out with some heat, a hammer, and chisel. A new plug is needed after that. They are probably cheap at the dealer, but can be had for $10 on Amazon.

While I suppose you can reuse the rounded out plug, you would have to chisel it back in the other way. Not recommended as you'll have no idea how tight it gets and there is only so much beating that POS soft metal plug will take. See my above picture for how the plug gets slightly fucked up while chiseling on it.

 

Ordered Ravenol for our other vehicle. While I was putting it in, I opened up the taco transfer case and took a little finger dip out of the t-case to smell and feel it. then I felt the front diff with the mobil 1 75/90 fill. The front diff is a little more slippery and onion smelling than the t-case fluid.

the ravenol 75w feels and smells JUST like the fill thats in the taco t-case. It's just a little thicker feeling and less slippery than mobil 1 75/90.

Ravenol site says it meets TOYOTA 08885-81081,which is nowhere but a search pulls up lots of russian sites. The sites show:





and this, so the russians be like: WTF is this? why are there two different types of 75w for toyota. At least I guess because I can't read Russian. So toyota is just confusing everyone with this 75w crap.

I ordered two bottles from Amazon at just under $15.00 each. NO sulphur smell out of the taco t-case fluid I sniffed and none out of this one. Figured if it smelled, felt, or looked different I'd just save it for next time I have to change our other vehicle, since ravenol is spec for the audi.

Mobil1 75-90 is around $12/13 around me. Paid the extra dollar and change from amazon to get this one.

Since it smelled the same, felt the same, and is 75W, I put the other bottle in the taco.Some little bits of metal out of the factory fill but still pretty clean. Most challenging part is figuring out how to open the bottle. It's a friggin 3 step process I couldn't figure out so I just took a pair of scissors and said eff you. You'll see what I mean.

Went 25 miles in 4hi in sand, rocks and crap today. Felt fine. nothing clunked. nothing grenaded. Drove to and back 120 miles each way. no problems.

So...go

$30 mobil 1 75w90 mobil 1 104361 75W-90 synthetic gear lube - 1 quart (pack of 2)

mobil 1 75w90 like others and not meet spec? or spend $1 more and not meet spec? but at least put something in that smells and feels like spec? OR, lets keep this discussion going like the 4runner groups have, since 2012!!!! and put in what you want as long as it's not 0w20 motor oil like some people had in their diffs?

So now: valvoline max life flush in tranny (about 4000 miles since flush) 75w90 mobil 1 in front diff, 80/90 valvoline in rear diff, and ravenol 75w in t-case. I forget why valvoline in rear diff? I have 4 bottles of mobil 1 75/90 on my shelf. I think valvoline just to flush out the rear diff a bit because it was so dirty before I put mobil 1 75/90 in? maybe a little thicker to see if my howl went away? I really can't remember why and it was only a month ago or so. I remember I had a reason though. I just know it's not 75/90 because I saved the 4 bottles of mobil 1 for a near future flush. Everything's felt fine and everything's got a new fluid in it now. Have another trip in two weeks. I'll let you know if anything explodes.

 

I inadvertently put the redline MT-75W90 GL-4 oil in the front/rear diffs, along with the manual trans. Am I gonna be ok or should i switch to the 75W90 GL-5 in the front/rear diffs ?

 

i wouldnt worry about it. I always just put 90w in mine lol

 

Rounded the 10mm hex on the front diff drain plug. Ordered a new one this morning but need to heat it and drive in a T55 torx per recommendations I have seen from others that had the same issue.