Gear oil limited slip or no slip recommendation

[Patrick0525]

Both AWD 14 Venza-120k mi and 21 RX350-17k mi call out Toyota LT non-slip gear oil. On the Venza, I have always used Mobil 1 Delvac 75w-90 with 5% Red-line friction modifier added which would make it closer to the Toyota LX limited slip gear oil. Delvac has zero limited slip additive. So far the Venza has received three transfer/rear differential oil changes with no known issues, chatter or unusual noise. It seems to run very smoothly.

Most synthetic gear oil on the market are considered limited-slip and one the reasons for making the Delvac+Red-line was cost ($30/gal) and general compatibility.


On the 21 RX350 was is the recommendation? Considering that both Venza and RX350 do not have the same transfer case/ rear differential, do I do a) or b)?

a) delvac + 5% Red-line
b) delvac and no additives

Maybe I am over-thinking this? Lol

 

[Rob_Roy]

If Toyota doesn’t call for a friction modifier in either application, why would you add it?

 

[4WD]

Both AWD 14 Venza-120k mi and 21 RX350-17k mi call out Toyota LT non-slip gear oil. On the Venza, I have always used Mobil 1 Delvac 75w-90 with 5% Red-line friction modifier added which would make it closer to the Toyota LX limited slip gear oil. Delvac has zero limited slip additive. So far the Venza has received three transfer/rear differential oil changes with no known issues, chatter or unusual noise. It seems to run very smoothly.

Most synthetic gear oil on the market are considered limited-slip and one the reasons for making the Delvac+Red-line was cost ($30/gal) and general compatibility.


On the 21 RX350 was is the recommendation? Considering that both Venza and RX350 do not have the same transfer case/ rear differential, do I do a) or b)?

a) delvac + 5% Red-line
b) delvac and no additives

Maybe I am over-thinking this? Lol

Wouldn’t Mobil 1 or Valvoline already have LSD FM’s?
(I use Delvac 1 “neat” in G80’s and e-lockers) …

 

[Lubener]

No limited slip, why use an additive or gear oil fortified for that type of differential?

 

[D60]

Funny this came up. While not the same vehicle I just did an '06 Taco 4x4. I used M1 75W-90 which is supposed to have additive.

I kinda thought I detected some chatter in my post-test drive, but it was subtle and almost seemed like something unrelated, so I left it alone.

About a week later I was chatting with the owner and he described what absolutely sounds like chatter. I did some more research and Tacoma forums seem to suggest if you use gear oil with no additive, you typically need a double dose of FM. If the gear oil already has FM, then add one bottle.

Some also said the M1 doesn't seem to do well at all in the Tacos in this regard, but that doesn't make sense to me. I have to imagine their base gear oil is just fine and the proper dose of FM is all it needs.

I grabbed some of the 7oz tubes of CRC (AutoZone) and the 4oz containers of Lubegard (O'Reilly). I think I'll try a full tube of CRC but open to input

 

[Marcozi]

Using a diff lube with frictions modifiers (for an LSD) in a diff that doesn't need a friction modifier will not damage the non-LSD diff.

 

[Patrick0525]

Using a diff lube with frictions modifiers (for an LSD) in a diff that doesn't need a friction modifier will not damage the non-LSD diff.

This is my thought exactly. I didn’t want to influence forum members comments.

 

[Patrick0525]

If Toyota doesn’t call for a friction modifier in either application, why would you add it?

My thought was to make the gear oil equivalent to Mobil 1 1qt bottles which is considered lsd.

 

[GSCJR]

Wouldn’t Mobil 1 or Valvoline already have LSD FM’s?

Yes

 

[Patrick0525]

If Toyota doesn’t call for a friction modifier in either application, why would you add it?

My thought was to make the gear oil equivalent to Mobil 1 1qt bottles which is considered lsd

Funny this came up. While not the same vehicle I just did an '06 Taco 4x4. I used M1 75W-90 which is supposed to have additive.

I kinda thought I detected some chatter in my post-test drive, but it was subtle and almost seemed like something unrelated, so I left it alone.

About a week later I was chatting with the owner and he described what absolutely sounds like chatter. I did some more research and Tacoma forums seem to suggest if you use gear oil with no additive, you typically need a double dose of FM. If the gear oil already has FM, then add one bottle.

Some also said the M1 doesn't seem to do well at all in the Tacos in this regard, but that doesn't make sense to me. I have to imagine their base gear oil is just fine and the proper dose of FM is all it needs.

I grabbed some of the 7oz tubes of CRC (AutoZone) and the 4oz containers of Lubegard (O'Reilly). I think I'll try a full tube of CRC but open to input

Please update us on ur findings.

 

[Rob_Roy]

Just run the Delvac by itself and save the FM for something that needs it.

 

[Patrick0525]

Just run the Delvac by itself and save the FM for something that needs it.

Too late I already spiked 1gal with fm and the other gallon of delvac is untouched.

 

[4WD]

Too late I already spiked 1gal with fm and the other gallon of delvac is untouched.

Mix them half and half …

 

[The Critic]

Funny this came up. While not the same vehicle I just did an '06 Taco 4x4. I used M1 75W-90 which is supposed to have additive.

I kinda thought I detected some chatter in my post-test drive, but it was subtle and almost seemed like something unrelated, so I left it alone.

About a week later I was chatting with the owner and he described what absolutely sounds like chatter. I did some more research and Tacoma forums seem to suggest if you use gear oil with no additive, you typically need a double dose of FM. If the gear oil already has FM, then add one bottle.

Some also said the M1 doesn't seem to do well at all in the Tacos in this regard, but that doesn't make sense to me. I have to imagine their base gear oil is just fine and the proper dose of FM is all it needs.

I grabbed some of the 7oz tubes of CRC (AutoZone) and the 4oz containers of Lubegard (O'Reilly). I think I'll try a full tube of CRC but open to input

I think I mentioned this in the other thread, but certain Toyota products from that era are extremely sensitive to chatter. For unknown reasons, M1 + additive seems to be the worst offender.

For similarly unknown reasons, conventional plus additive seems to work best.

 

[D60]

I think I mentioned this in the other thread, but certain Toyota products from that era are extremely sensitive to chatter. For unknown reasons, M1 + additive seems to be the worst offender.

For similarly unknown reasons, conventional plus additive seems to work best.

Interesting, they were saying dino 80W90 plus a double dose of additive was the way to go.

I still struggle to believe M1 is "faulty" in that regard. I'm not an M1 fan boi -- but seriously, it's just gear oil!

I dunno, I guess we'll see.....

 

[CharBaby]

In our 1st generation RX300 that was not a rear LSD Differential, I used Mobil1 75/90 synthetic w/LSD additive without any issue and the same for the FORMULA in my signature as it too does not have a rear LSD Diff.

 

[Patrick0525]

In our 1st generation RX300 that was not a rear LSD Differential, I used Mobil1 75/90 synthetic w/LSD additive without any issue and the same for the FORMULA in my signature as it too does not have a rear LSD Diff.

Collaborating information. My 14 Venza 120k has been on a diet of Mobil 1 75/90 + 5% Redline lsd additive for the last 80k. The 1gal Mobil 1 75/90 is lsd additive free.

 

[CharBaby]

I think what you’re talking about is Mobil Delvac 1

 

[Patrick0525]

I think what you’re talking about is Mobil Delvac 1

Correct. Mobil 1 Delvac

 

[CharBaby]

https://www.amazon.com/Mobil-Synthetic-SAE-Grade-122035-1/dp/B007WVI5G6/ref=asc_df_B007WVI5G6/?tag=hyprod-20&linkCode=df0&hvadid=693070740373&hvpos=&hvnetw=g&hvrand=1019608460495473385&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9052058&hvtargid=pla-1944227664869&psc=1&mcid=a59cc7a0c3ee3e4b9569226d32f61b08&gad_source=1