Can i Use 75W-90 gear oil instead of 75W-85 for the diffs

I had my 2017 tacoma rear diff changed by the dealer because fill plug is stuck . Only cost 99$ . They used synthetic

$29 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90. They said it’s cheaper as it’s bulk oil .

 

$99 seems reasonable for dealership prices. However I got the oil to do both from Walmart for under $65 and the transfer case oil for $25 from Amazon. Stuck drain and fill pugs suck so I understand leaving that to a pro.

 

It's made by Warren, so good stuff. Their Supertech oil is also made by Warren. Run both with confidence.

 

What part of the country are you in @stickbug1 ?
Reason I ask...
I'm in Phoenix AZ. Hotter than the hinges of hell here for a solid two months and just toasty the rest of the time. I tend to cheat towards thicker oil's here because of the higher temps. Fluids that get changed multiple times a year like engine oil get thinner in the winter an thicker in the summer but never a wild swing just bumping it up one rating or down.

The difference between your two oils is negligible but running

$29 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90 gear oil in Manitoba, Canada will be a more noticeable difference than running it in the Sahara Desert.
So it's a "YES! But..." kind of answer.

 

I know. I'm using the motor oil too. I actually started using Shell Rotella gas truck cus I got a bunch of quart bottles on clearance not long after I get the truck new then switched to super tech. I noticed no difference in how the engine runs so I got full confidence in the gear oil too.
A few guys in oil threads question how good it is. I'd like to send a uses sample to Blackstone to prove it but this time I forgot to take the sample and had my drain pan mixed with gear oil.
Only problem with getting the ST gear oil is my local store shows it in stock online but it's never on the shelf. I ordered mine for pickup then it got changed to free home delivery.

 

Amazon carries Redline if you want to keep running 75w85, but it’s not cheap.

 

Why are you using 90 instead of 85?

 

I just changed mine with 85 140

 

Because there is very little difference between the two in viscosity. 90 is only a bit thicker at operating temp than 85. They spec 75w85 most likely for a tiny amount of fuel economy to meet government regulations. 75w90 is a more common gear oil so there the benefit of it being cheaper and much more available.

 

And I noticed in cab is much quieter . Can’t hear the diff howl now

 

that’s easy. If you want a challenge tell us how to replace the clogged manual trans breather atop the bellhousing and relocate it.

 

^You'll need to consult an endangered species (manual trans) specialist for that one!

 

I love how everyone thinks Amsoil is super expensive. Been running 75w-110 for years (because I tow during the summer). If you subscribe to an Amsoil membership you get 25% off all of anything you buy for 6 months.

out of all the oil brands I’ve used Amsoil ALWAYS changed the cleanest (noticeably).
Get good lubes, especially if you like peace of mind and driving your rig hard

 

$14 GENUINE TOYOTA GASKET KIT FOR TRANSFER AND DIFFERENTIAL SERVICE

https://www.amazon.com/gp/aw/d/B017V4BAXI?ref=ppx_pop_mob_b_asin_title

 

I didn't buy new crush washer gaskets. I just re used the original ones. They don't seem to be leaking at all. I don't think I would reuse them again though.

 

Yes

 

The fact you have to subscribe to an oil membership is

 

not if you buy $100+ worth of products

 

Anyone know the orientation of the crush gasket for rear diff drain and fill ?

 

yes