I've searched on several different boards and can't quite find a definitive answer that suits me, so I'll post my question here:

Is it ok to use Mobil 1 synthetic gear oil in 75w-90 weight in the differentials of a 1997 Toyota 4Runner 4x4 5spd (standard diff, no locker)?

I ask this because the Toyota manual calls for 80w-90 and I want to make sure it's not a problem.

Chris

 

I thought that 80w was only for BELOW zero applications?

The Chilton's I'm looking at says 90w for ABOVE zero F.

j/c - what was the price you saw on this Mobil 1 75w/90 and where?

~a

 

I'm using 75w-90. Isn't that similar to 90w at high temps? Anyway, I got the Mobil1 at a local parts store for $7.99/bottle.

Chris

 

I used Amsoil 80 - 90 in my rear diff. I highly doubt you will experience anything negative from going 75 - 90. You may want to switch over when you get a chance. It would bug me.

 

The manual recommends 80W90 on my rear diff, but I'm using Amsoil synthetic 75W90 in there right now and I don't see any problem at all. 80W90 is a little heavier than 75W90 so I guess it does not make any difference as long as there is oil in the differential case. The fluid in there is synthetic so I have a peace of mine knowing it will do it's job to lubricate the ring/pinion gear and bearing in there.

Noel

 

I was wondering the same thing before I did my fluids and found some info about others switching and using mobil1. Though I don't remember the threads, it was concluded that it was ok to use the same weight in the front and back. I couldn't find anything but 75w-90 at my local auto store. I did the switch last month and haven't had any trouble.

 

I currently run Redline in both diffs and my tranny. I used 75-90 in the diffs and Redline's MTL 90W in the trans. I've put on about 14k miles without any trouble. It even works with my Lockrite locker.

 

I blew a tranny using Redline.

1988 Mazda B2200.

 

I use 75W-90 Amsoil syn. gear oil in my diffs & transfer case. No problems here.

 

Care to expand? C'mon...details!

 

My lowrider-show-winner turned drag racer Mazda B2200 truck didnt like me slamming the gears at the track I guess.

I single-handedly blew the 3rd gear synchro after an amazing 17.6 @ 76MPH run in the 1/4 in which I beat a coffee-can Toyota Corolla with a 4 foot spoiler and 19-inch wheels.

How do you like them apples?

 

oh man, you gotta show us pics of this truck!

 

So maybe it wasn't the gear oil's fault? :pat: BTW, I dig them apples. I once had a no-show-goin', unloaded torsion bar havin', 2" block wearin', 17" Focal spinnin' 87 Yota. Maybe I would have given you a run for your money? Then again, maybe not...it burned so much oil that bystandards thought it was on fire as I roared past. After the axle seals started leaking it would do hella burnouts though!

 

Dude, that sounds sweet.

I will post some pics of my work of art this week.

One with the Roadsters, and one with the "speed" wheels - tucked of course.

 

this was barely touched upon up higher but with a locker should you change to a different gear oil?

Probably a stupid question but I don't know the answer yet :pat:

 

I was told by Redline that it would work fine with my locker. I would think that most gear oils would work for a locker because they are already designed with shear protection in mind (for the ring/pinion/spiders, etc.) Now if you run a clutch type limited slip (LSD) I would be a little more careful in choosing gear oil. Most manufactures will spec if thier stuff is okay to use in clutch-type LSDs. Most of the time all it takes is a few minutes to read the bottle or call the manufacturer.

 

Good grief. Once I finally start getting answers, they start flowing in. I still have the Mobil 1 in the diff, but I have all Redline fluids in my garage waiting to be poured in (gonna do the entire drivetrail at next oil change). For the diffs, I bought Redline's 75w90NS. It's a GL5 gear lube without the friction modifiers for LSDs.

I'm going to use MT90 for the transmission (5spd) and t-case.

Chris

 

I would not go straight 90 in the MT.

 

Read the product specs, it is not a straight 90w oil. It is a 75w90 GL4 oil designed for manual transmissions and transaxles. I've used it before in toyota MT's, it's a good product.

http://www.redlineoil.com/redlineoil/mtlti.htm

Chris

 

So, I'm going to do my tansmission and transfer case soon. The thing is, what weight should I go with? I'm going to be in Bozeman, Montana for the winter. For those of you who don't know, it get's quite cold there. Anyways, should I go with a thinner weight or should I sick with the stock recogmedations