Gear Oil Question

[DC runner]

Replacing the Gear Oil. Want to go full Synthetic. Local shops don't have Synthetic 80w-90.

They do have Royal Purple 75w-90 full synthetic.

Anyone run that weight? Any issue with it being "too" light for the winter? As we move into summer, I am not concerned right now; as the temp will keep it at the 90 viscosity, but is the 75w too light?

 

[Lexus LX]

75w-90 is the recommended viscosity.

 

[DC runner]

Err? Not according to my service manual....

I have the v8, full time and my manual and service manual states 80w-90, but if 75w won't make an issue.. then, good.

 

[DC runner]

From the service manual:


HINT:
If necessary, fill the rear differential carrier assembly
with hypoid gear oil.
Oil grade:
Hypoid gear oil API GL-5
Recommended viscosity:
Above -18°C (0°F) SAE 90
Below -18°C (0°F) SAE 80W or 80W-90
Capacity:
Front differential carrier assembly:
1.35 to 1.45 litters
(1.43 to 1.53 US qts, 1.19 to 1.27 lmp. qts)
Rear differential carrier assembly
3.00 to 3.10 litters
(3.17 to 3.27 US qts, 2.64 to 2.72 lmp. qts)

 

[MikeInNH]

75w-90 is fine.

Full synthetic will have a wider range anyways. Royal Purple is fine..Although I find it expensive to other comparable products.

 

[mrpanic7]

I'm getting ready to do my diff's also, which synthetic you guys run and why?

 

[DC runner]

Thanks!

Found it odd that they didn't carry Synthetic 80w-90. Maybe not popular...

 

[Dawg4Runner]

Replacing the Gear Oil. Want to go full Synthetic. Local shops don't have Synthetic 80w-90.

They do have Royal Purple 75w-90 full synthetic.

Anyone run that weight? Any issue with it being "too" light for the winter? As we move into summer, I am not concerned right now; as the temp will keep it at the 90 viscosity, but is the 75w too light?

You should be fine running that. Just make sure it's API GL-5. Also make sure it has additives for limited slip if you're running limited slip. BTW, the current spec for 2003-2008 4Runners is 75W–85 API GL–5 pursuant to TSB DL003-07

The differential gear oil used in 4Runner and FJ Cruiser vehicles has been changed to a 75W–85 GL5 synthetic gear oil beginning with the 2008 model year. This new synthetic gear oil is compatible with 2003 – 2007 model year 4Runner and 2007 model year FJ Cruiser differentials. Please refer to the Parts Information section below for information about this gear oil and use this gear oil (or equivalent) when filling front or rear differentials with oil.

Why not just run Toyota factory fluid. It's exact spec and it's synthetic.
PN 08885–02606 (LSD)
PN 08885–02506 (non LSD)

 

[MikeInNH]

Why not just run Toyota factory fluid. It's exact spec and it's synthetic.

Probably because Toyota DOES NOT make fluid. It's made for them by one of the oil companies and then the Toyota label is slapped on it...and the price is multiplied by 3.

 

[Zuke]

I use Mobile 1 75w-90, why? because I get it for $5qt at advanced auto parts.

 

[DC runner]

75w-85, odd. Neither of my two closest AUTO parts stores even sell that.
Why, Toyota, why? Oh wait, to promote more money?

My understanding is that most runners have LSD. Did they put in locked diff's?

 

[Zuke]

My understanding is that most runners have LSD. Did they put in locked diff's?

They do not have LSD in the 4th gen. (its an electronic braking system) The late trail edition had a locker. Using the oil with the LSD additive already added will not hurt anything.

 

[DC runner]

Gotcha. So open rears and it uses the VSC system as an electronic slip control.

 

[geurillawarfare]

Replacing the Gear Oil. Want to go full Synthetic. Local shops don't have Synthetic 80w-90.

They do have Royal Purple 75w-90 full synthetic.

Anyone run that weight? Any issue with it being "too" light for the winter? As we move into summer, I am not concerned right now; as the temp will keep it at the 90 viscosity, but is the 75w too light?

New recommendation is 75W-85. Good luck finding it. I put Mobil 1 80-90 in mine, has been working fine.

 

[MikeInNH]

You do NOT have to get 80w-90 gear oil.

Full synthetic 75w-90 is perfectly acceptable.

 

[DC runner]

Yea. I saw the royal purple is 17.99 a Qt, and the Mobil 1 Full Synthetic is 10.99, the Castrol and Valvoline full synthetic are 7.99. So, yea. Royal Purple is a bit pricey for my taste.

 

[black_120]

I use Mobile 1 75w-90, why? because I get it for $5qt at advanced auto parts.

I'm getting ready to do my diff's also, which synthetic you guys run and why?

New recommendation is 75W-85. Good luck finding it. I put Mobil 1 80-90 in mine, has been working fine.

Yea. I saw the royal purple is 17.99 a Qt, and the Mobil 1 Full Synthetic is 10.99, the Castrol and Valvoline full synthetic are 7.99. So, yea. Royal Purple is a bit pricey for my taste.

Use an online coupon for Advance Auto parts and pick up in the store. You should be able to get it for $5-6 per quart.

I went with M1 because of the coupon and it can be found anywhere.

 

[GMZ]

Go with Mobil 1 75w-90

 

[jimithing]

I just changed mine today and used Mobil 1 75w-90. BTW, for anyone looking to do this soon the Autozone's around here have it on sale for $6.99/quart. Not sure if that's a nationwide sale or not.

 

[message]

I run RP 75w90 throughout and definitely noticed a difference after the change. Less road noise and even gained about 1-2mpg.