gomezza

I was reading in my 99 4runner's owners manual about the Gear oil for the rear. It says that if it is above 0F use SAE 90 and if its below use 80W-90. Where in the world can I buy pure SAE-90 oil!? Did toyota make a mistake when they wrote this? I mean they made the front clear w/ ADD 75w-90.... Anyone know whats going on here... Thanks guys!!

H-

superjoe83

just use 80-90 it will be fine, or if your in a cold climate use 75-90

kevin444

Im using redline 75w-90 synthetic.

gomezza

But what I want to know is did toyota make a mistake writing that or is there really a SAE-90 ?

superjoe83

Ive never seen it, maybe they have it at the dealer

gomezza

haha no... i went to the dealer and they use 80w90 i've done a search for it and found nothing! 80 is the weather correct? and 90 is the weight of the oil.. so sae-90 would be the same thing... right?

superjoe83

not exactly, 80 means that the oil will flow like a standard 80 weight when cold (freezing) and will flow like a straight 90 weight when hot (200 degrees), 80-90 varies its thickness with changes in temp, reg single weight oil will have a constant thinning rate, so basically a 80-90 flows good when cold and will protect like a thicker oil when hot

gomezza

thanks for your help guys... i just didnt want to put the wrong oil in there. I plan on having this rig for a long time (unless gas hits 3.00 a gal)


H-

4Crawler

iTrader: (3)

Likely in some parts of the world, straight weight gear oil is more available and likely is less expensive the the more refined multi-viscosity oil. So Toyota probably writes the oil requirements to allow for this. I run various Redline synthetics in my '85:

http://www.4crawler.com/4x4/index.sh...ntheticGearOil

smiljko

It is avalible in my country -INA hipenol 90 ,but it is crap-it is for yugos,ladas etc.

Cape yota

I was reading the same thing this weekend. But I was wondering what "with A.D.D" and "except A.D.D" means. Can someone tell me what the A.D.D stands for?

4Crawler

iTrader: (3)

Usually that stands for: Automatic Disconnecting Differential

More info:
- http://www.off-road.com/toyota/tech/add/index.htm

Cape yota

Okay, Automatic Disconnecting Differential, got it. My question now is why does the manual specify two different capacities and viscosities for A.D.D and except A.D.D? Does this mean that some 4WDs came withouth the ADD?

4Crawler

iTrader: (3)

Yes, over the years 3 different front axle/hub setups, ADD w/ drive flanges and then either manual or automatic hubs with no ADD:

http://www.off-road.com/toyota/tech/aisin/index.htm

I imagine ADD has more moving parts that may not work with a thick oil in the cold, so they spec a lighter weight multi-vis oil. Also, the ADD mechanism may add or subtract some volume of oil capacity.

With gear oils, the two numbers are ColdWeight-W-HotWeight. So, when hot a 75W90 should be the same viscosity as an 80W90 or even a straight 90W oil (i.e. 90=90=90). The only variable is the cold weight, when cold a 75W90 is thinner than an 80W90 which in turn is thinner than a 90W (i.e. 75<80<90). Think of a straight 90W oil as 90W90. As long as you run something thick enough, when hot, to meet the spec, and the correct grade (GL-4 or GL-5 as needed) you should be fine. So if Toyota calls for 90W-GL5 oil, a 75W90 or 80W90 or 90W GL5 oil would all work fine. The multi-vis oils will simply not get as thick when cold, so they will have less drag and flow better when you start off in cold conditions.

I run a 75W250 gear oil in mine (Redline Heavyweight Shockproof) and it works great. The Redline oil base is a 75W90 and then special additives are used to resist thinning at high temps (thus boosting the hot viscosity from 90 -> 250). I like it for use in slow speed rock crawling, where you have very high gear loads and very slow gear rotation speeds. At 206:1 in low-low range, the tires may take 15-20 seconds to make one rotation and the gear oil needs to cling to the ring gear most of that revolution as it comes out of the oil pool in the diff until it comes around to meet the pinion gear. The Heavy Shockproof oil sticks like glue. I had an axle housing that I took off my truck in 2000 and it still have a thick film of Redline oil inside 5 years later.

woodworth

hey cape yota:

what beach is that, i've got a sticker for sandy neck. hope to use it more
this summer though. i'll look for you, i've got a 94 runner -grey

see ya

Woody

Cape yota

Roger, thanks for clearing that up with such a detailed and informative anwser!


woodworth, That is the outer beach at Nauset. One of my favorite places on earth. That reminds me, they start selling this years stickers on Thursday...