Is there a oil for both differential and transmission.

can I use a certain oil for both the transmission and rear differential. 2000 2.4 Tacoma mt. The stores around me only carry valvoline and mobile1

 

I've been using 75/140 Mobil in both for several years and it ain't blowed up

 

I've been using Valvoline 80-90W in all my vehicles for 45 years without problems. I change the trans/diff/transfer case/diff oil about every 20-30K miles, and the motor oil (also Valvoline) every 3-6K.

 

What does the owners manual call for in terms of viscosity and GL rating? That's what matters.

Some vehicles use the same in both, others do not. And there's certainly no reason not to use an off the shelf name brand that meets spec.

I'm assuming your trans is manual? Be sure that if the spec is GL4, that's what you use. Using GL5 can damage syncros.

If you have notchy shifting, I recommend trying

$34 Ford XT-M5-QS Full Synthetic Manual Transmission Fluid - 1 Quart , black

Ford XT-M5-QS. It's pricey, but works quite well. Be very careful at your Ford dealer that you get the exact number. There are a couple other of their products that are close in number, but not the same product.

 

Thanks for the responses the manual says gl4 or 5 and I know any of that is fine for the differential but I was reading online that gl5 is bad for the transmission I'm guessing just a myth. So mobile1

$30 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90 or valvoline synthetic for my manual transmission and rear differential is fine?

 

Gl4/5 Lucas in my diffs, trans and t-case.

 

I went to Autozone and put 75w90 valvoline in rear dif and pennzoil synchromesh in the transmission that they recommended is this ok for my truck

 

No idea, if it doesn't say gl4 or gl5 on it it's not what the manual recommends. However it could be perfectly fine.

 

Just looked at the bottle it says gl3

 

I would like to see some published material from a reliable source stating the conditions under which GL5 can damage the synchronization mechanisms in manual transmissions. I've been using GL5 since 1990 without synchro problems.

 

Typical internet hype. If Toyota says I can use gl5 in my manual I trust them. Imagine the warranty claims if it truly hurt the synchros

 

Neither you nor @skeezix read what I posted correctly. I said "Be sure that if the spec is GL4, that's what you use. Using GL5 can damage syncros."

In the SCCA world I came from many a transmission that spec'd GL4 developed syncro issues, all of which were running incorrect fluid. Never saw a failure on one running GL4.

Directly from Wiki https://en.wikipedia.org/wiki/Gear_oil

EP additives which contain phosphorus/sulfur compounds are corrosive to yellow metals such as the copper and/or brass used in bushings and synchronizers; the GL1 class of gear oils does not contain any EP additives and thus finds use in applications which contain parts made of yellow metals.


GL-5 is not necessarily backward-compatible in synchro-mesh transmissions which are designed for a GL-4 oil: GL-5 has a lower coefficient of friction due to the higher concentration of EP additives over GL-4, and thus synchros can not engage as effectively. Also, transmissions which explicitly call for GL-4 oil may have been designed around this lower concentration of EP additives and thus may contain yellow metal parts which GL-5 will corrode.

If the spec is GL4/5, yes, that means you can run either one.

You've heard of Redline MT90 I'm sure. Folks around here like it. GL4. From their specs "Safe for brass synchros, as it lacks the reactive sulfurs found in most GL-5 oils that cause damage"

There are many Amsoil lovers around here. (not me). From their site we find

"Replaces GM part #12346190 and Chrysler part #4874459. Examples of transmissions and transaxles requiring a 75W-90, API GL-4 lubricant include certain models of Hyundai, Infiniti, Kia, Lexus, Mazda, Mitsubishi, Nissan, Suzuki, Toyota, Volkswagen and Hino.

Examples of street rod and muscle car transmissions include Muncie, Borg Warner, Saginaw, Ford Toploader, Dearborn and New Process."

Also note I did not tell the OP to use GL4. I don't know what his particular trans calls for. All I did was offer a caution that if it asks for GL4 specifically, use it.


I stand by my original post, and the above is enough evidence why.

You use what you wish, believe what you want. I'll go with the combo of experience, engineering specs and tribologist testing results.

 

His trans calls for gl4 or gl5. Both are acceptable by engineers at Toyota

 

Which he posted after I asked the question.

As I stated, yes, either can be used in that case.

 

The rear ends are specced for

$30 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90 if I remember correctly. But you'd have to look that up on the transmission, I drive an automatic so I don't keep up on the manuals. Amsoil Severe Gear is supposed to be the cat's meow from what I understand, I plan to give it a whirl when it comes time to change out my gearbox oils.