jtmaxx7

I'm planning on changing my diff oil this weekend. Any suggestions on which oil to use? I went to checkers last night and the Mobil 1 is over $11/qt. I guess that's not too bad considering it's not like motor oil where you change it frequently. Which brings me to my next question. I don't think it has been chaned, EVER and the truck currnetly has over 62K. If I it is a pure street queen is it okay to change it every 30K?

KZN185W

iTrader: (1)

You need to change it every 30k even if it's a street queen. I use Red Line 75W90. It has the LSD additives needed by the rear LSD.

progress4m

I used synthetic blend Valvoline 75W90 in the front and transfer case and 80W90 in the rear. It is a lot cheper then Mobil 1.
I think any good brand of oil will work just fine.
Just make sure that oil you will use for differentials is made for hypoid applications and has GL-5 reting.
Also if this a stack 4Runner more then likely you do not have LSD so don’t worry about LSD additives.

jtmaxx7

I saw the synthetic blend at NAPA yesterday, almost half the price of Mobil 1. However, since I'm only going to change it every 30K I think I'll go with a full synthetic for peace of mind. ~$36 vs ~$18 for 3qts, not going to break the bank over the 30K miles.
As for the LSD, I don't think I have to worry about that in my prerunner as well.
Thanks

Gerdo

I've been using full syn in all boxes and diffs. I saw about 2 mpg gain. It shifts better. Go full syn.

jtmaxx7

If I want to flush the diff a little before filling can I flush it with regular motor oil or cheaper gear oil? I don't really want to pay 11bucks for an extra quart to flush. I beleive in the manuel it calls for 2.8 qts for the rear which would leave me only .2qts to spare.

Ironmike4x4

Thread hijack: In my owner's manual it says to use SAE 90 for the rear axle, but cannot find anyone with synthetic. Can I use 80w-90 in the rear? TIA

progress4m

Yes, you can.

Ironmike4x4

Thanks. I did see your post earlier, just wanted to make sure.

jtmaxx7

Just came from Checkers, can you put mobil 1 75w-90 ($12/qt)? What about the Valvoline pure synthetic ($10/qt), has anyone tried that one?
Anyone regarding a flush with fresh oil?

jtmaxx7

I found Mobil 1 for $7.99/qt. Bought.

02SE

I've been using Mobil 1 75w90 in my transmission (5 speed), transfer case, front diff, and rear axle for 8.5 years. No problems at all.

As for flushing, I wouldn't bother.

I would drive your 4Runner a ways, so the gear oil is hot when you drain it though. This will ensure a quicker, and more complete drain.

jtmaxx7

Just finished. Takes a while to pump the new oil in though. Yeah as for flushing I just gave it a few shoots (had to make sure there was enough to finish the job) and let it drain for about 15-20min.
Oh yeah, there was some huge pieces of metal on the magnet. I would say about 1/4 inch in diameter. I threw it away when cleaning up, I ment to take pictures. Hope this is alright.
Thanks for all the advice, I feel confident about my choice in oil.

mkgarrison5

i noticed when i changed the rear diff i had flakes but nothing that big. mine has 79k miles and i dont think the front diff has ever been changed. thats next on the list for me.. if you use synthetic can you get more than 30k miles between changes bc i drive about that much a year! thanks guys

jjrgr21

i use royal purple, about $10 a qt fully synthetic and if you need a lsd additive it's already mixed in.

k_southman

Are all the above listed oils safe to use with the factory E Locker? I am leaning towards a full synthetic for front, rear and transfercase.

mkgarrison5

how long can i get out of a snythetic oil in my differentials?? i know change the regular oil at 30k mile but what about synthetic?

displacedAlaskan

I bought my runner back in November with 170,000 miles on it and am getting ready to start changing out the oil in the diffs and trans axle. I have no idea how often it was changed in the past, but I'm doubting that it was changed regularly if at all. Should I expect to notice a gas mileage increase because of the decreased friction after changing it out? I guess it probably would coast a lot easier...
Also, I read in the manual that I may need some sort of pump to put the new fluid back in. Is this true, and where can I get a pump?

Elton

i got this one from wal-mart when i change mine worked good heres my thread https://www.yotatech.com/forums/f2/finally-changed-gear-oil-116384/

91TPU

i bought a cheapo pump for like 5 bucks and it sucked so bad i didnt even use it, to be honest i didnt need to, i just tilted the bottle and squeezed the gear oil in, did it with both the front and the rear...