75w140 in transfer case and rear diff?

Ravenol FTMFW. (at least in my truck)

 

Good stuff, I'm running it and use 4WD about one every three months, I'll probably leave it in until 2026.

 

Same

 

You’ll probably want something thinner in the transfer case and rear when Winter comes around.

 

After the ECGS needle bearing mod, I put Lucas 85W - 140 in my front diff. In time I will probably will do the same in the rear diff. In a cold climate you probably want to run something thinner.

 

75winter-140 might be a bit thicker at ambient temp, but the winter or cold spec will be similar.
75winter-90.
Both oils get thinner when they are hot. The 140 will of course be a bit thicker than the 90 when they are hot.

 

Found this re: transfer case. A third party posting at
https://www.blauparts.com/blog/what-type-of-transfer-case-fluid-does-my-toyota-tacoma-take.html


Toyota Tacoma 75W Transfer Case Fluid
In the United States, Toyota started using transfer case fluid part number 08885-81080 in the Toyota Tacoma 4WD models in 2016. The 75W is an updated formulation compared to the standard 75W-90 gear oil that was originally recommended in the 2015 and older Toyota Tacoma 4WD models. Toyota transfer case fluid part number 08885-81080 is a 75W viscosity fluid and does not specifically identify with any GL (gear lube) specification, like the older recommended gear oils (e.g. GL-5).

The main reason Toyota chose to update to the 75W transfer case fluid was to improve the vehicles efficiency. By using a 75W transfer case fluid (vs the 75W-90), Toyota was able to improve the rolling resistance of the vehicle. This allows for less dynamic drag inside the transfer case resulting in improved fuel economy. The Toyota 75W transfer case fluid also offers better lubrication and flow to key areas of the transfer case when the transfer case is not given time to warm up. It also supplies better cold climate lubrication. These improved lubrication qualities offer improved transfer case longevity.

Some still choose to use 75W-90 gear oil even though the Toyota 75W transfer case fluid is specified. We feel this is illogical. The newer Toyota 75W transfer case fluid specification contains a more involved additive formulation, uses higher quality additives and advanced fully synthetic base oils when compared to the popular entry-level 75W-90 gear oils. The high-quality level of the Toyota 75W transfer case fluid formulation achieves the benefits of instantaneous quick lubricating flow, as well as, keeping excellent shear stability in high load heavy heat driving conditions.

• 2016-2020 Toyota Tacoma 4WD 3.5L V6 gasoline models use 08885-81080 or 08885-81081 transfer case fluid.

 

Well, I called my local Toyota dealer where I have previously taken it for service.

Their parts department stated for the 2016 Taco TRD Off Road, they use synthetic 75w/90 in the transfer case, the front diff, and the rear diff. No difference, same gear oil used in all 3 components.

I did ask if he was sure, meaning he was not quoting the specs for 2nd gen Taco. Nope, it was for 3rd gen. The only change was the 3rd gen getting the 0w20 synthetic for engine oil vs the 5w30 non synthetic for 2nd gen.

They do not sell it either. If you want to put in what Toyota uses, you have to get it by having the vehicle serviced by them. The cost they charge for 2 quarts of their branded synthetic 75w90 is $30 (CDN).

So this is different from what the owners manual states. Owners manual states just "75" for transfer case, no winter rated spec on it.

Very interesting. Makes me less concerned about the oils that were put into my Taco, but I will still go down to the 75w90 in my transfer case and my rear diff, but I am not in a rush now. We have a hot summer coming up so the 75w140 will cause no issues until I get this done either via the shop that did the work, or I might just do it myself. Plus I drive it very hard offroad 20 - 30 trips per summer, and a 4,500 ft elevation climb to start every trip.

So it depends on how my back is managing at that time. I have done 40 years of DIY on my cars and trucks but a lot less in recent years due to some messed up back issues.

 

i heard thicker oil gets rid of the 3rd gen diff howl

 

I never had a diff howl in my 2016 so no difference for me there.

 

If its synthetic you will be fine. Also with all the off roading you do just run it for 20K and swap it out.

 

In context: As good, if better at all.

 

Learn to comprehend a statement, marginal over is better. marginal under would be worse.

The PDF from your hero's states Amsoil is better. Better than dino or other synthetics.

I understand it's hard to admit when your wrong, but please try.

 

I’ve ran

$28 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90, 85w-140 (when I changed gears to 4.88’s for break in purposes) and now 75w-110.

I’m staying with 75w-110. Great for towing in all temps or cruising. Helps quiet down the “hum” some people hear when running 75w-90 as well.

this all for the rear diff.

min the front and t-case I run 75w-90

 

75W140 is good in the rear diff. Tolerates high temperatures (from wheelspin, towing) without breakdown. It comes only in synthetic. I've been running it in my 2nd gen and 3rd gen rear diff for years.

3rd gen transfer case should use Toyota LF oil or you might have difficulty shifting into 4WD in the winter. See: https://www.tacomaworld.com/threads/‘16-newer-transfer-cases.636057/ Redline MT-LV is an acceptable substitute: https://perryautolaval.com/products/red-line-mt-lv-70w-75w-oil-quart

 

Totyota dealer here puts toyota synthetic 75w/90 in all 3rd gen transfer case and both diffs, at least here. Just confirmed today. Not “75” as stated in the owners manual. I will be putting that in before winter. Lucas synthetic 75w140 in it now, and a hot summer has started here. Plus I drive it hard offroad and 4500 ft elevation climb each time before getting offroad so it will be fine until my next maintenance in a couple months.

 

Marginal in this context means "insignificantly different".

You place too much faith in Toyota's engineering spec. This is the same company that thought the 8in rear diff was sufficient for these trucks, that initially said the Auto-trans in the 2gen never needed fluid servicing, and had to recall leaf springs because of breakage.

Run Amsoil all you like. It's extra cost for no extra gain based on any credible information I'm aware of. Feel free to produce something I haven't seen yet.

 

Sounds like a good place to drop my thread that displays the differences of the common gear oils. No 75w-140 included yet though.

https://www.tacomaworld.com/threads/gear-oil-spec-comparison-nerdy-data-stuff.717149/#post-25523032

 

So you've shifted amongst 2hi-4hi-4lo a few times since the transfer case fluid change? If everything works then leave it.