Gear oil?

Still trying to get my tacoma up to par, and am going to change the gear oil, as well as flush the trans. But I was told to use 90w gear oil and I can't find it anywhere. My truck is a 99 prerunner with the e locker in it, so I do not need a friction modifier but I'm just wondering what gear oil I should use since I can't find 90w, and if synthetic is worth it?

 

I run Amsoil Severe Gear 75W-90.

IMO, synthetic is worth it. See this for complete recommendations.

 

I looked into Amsoil but couldn't find their stuff at o'reillys so I'm running mobill 1 75-90, just out of curiosity how often should I change my diff fluid?

 

That's what I used for mine this past fall. Mobil 1 Synthetic 75w90 in the rear, center, and front diffs. And I think it's Dex 3 or 4 now for the ATF? Look in your service manual but I believe it's every 30k or 50k. I did mine @ 110k cause she was mainly a street/highway queen

 

I run Valvoline 75-90 dino gear oil. I off road the shit out of my truck. You will be fine running dino gear oil don't waste your money on the over priced over hyped synthetic.

 

Toyota recomends changing the rear diff gear oil every 30K. IMO, it really depends on how you use your truck. If it is your daily driver, then every 30K miles is adequate. If your truck sees a lot of offroad use, then more often is probably better.

The main advantage to synthetics is they usually have better shock absorption and heat dissipation properties. Synthetics are worth it if you use your truck hard.

My personal choice is Redline 75w90. http://www.redlineoil.com/product.aspx?product=57904

My local source is Carquest Auto and I use Amazon for an online source.

$26 Red Line 57904 75W90 GL-5 Synthetic Gear Oil for Hypoid Limited Slip Differentials - 1 Quart

http://www.amazon.com/Red-Line-57904-Synthetic-Oil/dp/B000CPCBF0

 

!st gens do just fine with non-synthetic. That's what they came with. Use what you want. Been turning wrenches for close to 25yrs for a living. Do lots of oil samples on customer equipment. Some run synthetic some don't. Have not seen any less wear with synthetic oil in those engines or transmissions.. Like I said I wheel my truck harder than most and have never had gear failure due to using non-synthetic oils

 

That's the beauty of tacomaworld. Everybody has a personal opinion. Good to hear that dino oil has been working out for you man.

 

No worries.

 

I also just stick with the good old stuff. Just change it out on time.

 

I run 80/90 dino.
Recommended by a long-time professional gear-box mechanic

 

I run

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

75w-90 severe gear.

Napa stores can get Amsoil products, btw.

 

Isn't the whole purpose of synthetic that you can run it a lot longer than dino?

 

I wouldn't say that's the "whole purpose" but it's definitely one of the benefits.

Synthetic lubricants also offer better detergent properties (cleaner running), lower pour point (better cold flow properties), higher TBN (improved resistance to acid formation), and lower NOACK volatility (less evaporation).

 

All this and at the end of the day I have had to rebuild engines and transmission that were run on synthetic oil that were no where near the engine life expectancy. Oil samples are your best indication of wear. I do shit loads. I work on engines, transmission and generators for a living. Hell I own the business. . Like I have stated before I have seen no benefit from synthetic oil. I know this from experience not just some sales pitch from a commercial or sales man. But real life experience working on servicing and rebuilding engines for a living.

 

Are you suggesting that there are no real world differences between off brand oil from Dollar General and Mobil One Extended Performance Synthetic?

Interesting (no sarcasm).

 

I run this in my rear diff, front diff, and transfer case. I use mt90 in my 6speed. you can probably guess i like redline... if you get redline get the "NS" formula as they dont have the friction modifier. Also id get 75-140 like the link takes you to. the 140 is nice piece of mind when pushing the truck hard and I still get the same gas milage as with a 75-90...

http://www.redlineoil.com/product.aspx?pid=39&pcid=4

but really its not necessarily the oil that really matters, just change it regularily...

 

What I am saying is I do tons of oil samples on engines. We don't use dollar general oil. But all that matters with oil is the API rating.