75W-140 Gear Lube

[jcm414]

I need to change my differential/transfer case oil on my 4Runner. I was told by someone that works at an oil change shop that the best gear oil for my vehicle would be a synthetic 75W-140. However, my owners manual calls for 75W-90. I would appreciate any comments from the more knowledgeable. I'd like to know:

1. is 75W-140 safe to use?
2. if so, is there any additional benefit over a synthetic 75W-90? fyi - I do a lot of towing
3. if so, what brand would you recommend

Thanks in advance.

 

[Rand]

It will provide more protection... is it necessary.. thats the question.. you will also lose some mpg
probably 3% or so.

Are you sure your t-case takes gear oil?

 

[Pablo]

It may provide a bit more protection when warm. Hot day, pulling a trailer - 75W-140 would be good stuff. Ice freaking cold morning, ungaraged synthetic is good and thicker is not better when cold. Compare cold flow properties.

For the differential that is. Don't use 140 in the transfer case!

Amsoil Severe Gear comes to mind.

Where is cheeseland?

 

[dkcase]

quote:

---

Originally posted by Pablo:

Where is cheeseland?

---

Could be Switzerland. Now, if it were CheeseHeadland, maybe somewhere else.

Your point is well taken. If Cheeseland has a normal ambient temperature in the teens, or in the 90s, could influence what you say about a viscosity question.

 

[Jim Allen]

Cheeseland is Wisconsin!

1) Sure it's safe. Might cost you a touch of MPG in daily driving.

2) Towing = high gear oil temps. High gear oil temps = 140.

3) Any brand name "boutique" synthetic. I really don't think there's a lot to choose between them quality wise. They're all good! If you weren't in Cheeseland, I'd propose something completely different and recommend the LE 607 (even though it's a straight 90 mineral oil). It worked extremely well in my tests at reducing oil temps, but it has only a -11 F pour point, so Wisconsin might be a bit too cold. After the tests, I decided to make it my personal choice.

Aditionally, I would recommend that if you tow a lot, if it's heavy stuff (relative to your truck's GCVWR), to install a diff temp gauge. Doing so will give you the ability to monitor temps and that might help make the oil decision for you. I am surprised at how much I look at mine now. Case in point: I had to haul my 10,000 pound farm tractor on a 2500 pound trailer recently and towed about 30 miles at 65 mph (mostly level) and my truck's axle oil temp (a Ford F-250 with a 10.25 Sterling axle) stabilized at 125 degrees (45 ambient). That's after installing a Mag-Hytec cover, a Trutrac Limited Slip and LE-607 gear oil. In stock condition, with "regular old" gear oil, I can extrapolate from the earlier tow tests that I would have been at or over 200 degrees. It ran 170 empty.

 

[Jim Allen]

Let me add that I was talking ONLY about the axles, not the T-case.

 

[Jim Allen]

Toyotas use a Hotchkiss axle not a Salisbury (dropout vs integral). Every one I've seen has a drain plug.

 

[N Heat]

I've been contemplating this change also. I tow a trailer quite a bit with my old Yota pickup, and I was considering a change to 75 140 synthetic, but was worried about the winter temps. It rarely gets down below 10 degrees F here, so I would probably be OK. Jim, what is the LE 607 that you speak of?

 

[Islandvic]

I have run Valvoline Synthetic Blend 80-90 GL5 in my '96 Crown Vic and '95 K1500 Z-71 with OEM 3.73 locking diff.

Both seem to do well.

I belive if you have a limited slip diff (opposed to a locking diff) you may need a LSD additive.

LubeGuard and Amsoil make LSD additives.

Will the diff service be a DIY, or performed by the kwik lube?

Does the 4runner have a sealed diff, or one with a cover? I would drop the diff cover (if equiped and opposed to sucking out the fluid which most kwik lube's do) and clean it, then wipe down the bottom of the diff housing. My Z-71 had a built in magnet at the bottom of the housing that I had to remove all the goop from.

Good luck

what year is the toyo?

 

[Jim Allen]

LE607 comes from Lubrication Engineers, . It's an industrial grade oil that's used both in automotive and truck drivetrains as well as industrial gearboxes. It has some interesting additives, the main one being Almasol. I'll let you read up yourself at teh LE website, but it seriously reduced the oil temps in my diff... about 5 degrees over Amsoil in fact. Both oils significantly reduced my axle temps over dino 85W90 by reducing friction. Because of the relatively high pour point ( actually quite good for a straight 90), I don't think LE607 is for everyone, but I liked it enough to leave it in after the tests (shameless plug: which you can read about in Four Wheeler magazine in the July issue). My truck is either working like a dog or not working and it generally doesn't get that cold here.

 

[LC]

Why not use one of the best.
http://specialtyformulations.com/HDS-5.htm

 

[unDummy]

Food for thought, what would work better in the cold, a 75w synth or an 80w mineral oil??
Since you tow, your rearend will appreciate the thicker oil. Use the 75w140 synthetic.

Or, if you're paranoid, mix a 50:50 blend.

There are also those "110wt" oils here:
http://specialtyformulations.com/HDS-R.htm
http://www.torcousa.com/assets/files/rgo_racing_gear_tech.pdf

But, the 110wt hasn't been adde to the labeling yet. Hopefully, we'll see more 110wt's soon for those that want a thick 90wt or thin 140wt gear oil!
http://www.lubrizol.com/AutomotiveGearOil/j306_spec.asp

 

[ant]

Anyone try the Torco SGO? How does it compare to the more familiar Amsoil Severe Gear, Specialty Formulation HDS and Royal Purple?

 

[MolaKule]

quote:

---

LubeGuard and Amsoil make LSD additives.

---

Lubeguard makes them, Amsoil purchases them.