read end fluid?

[saabpowered]

Ok here's my problem, I have a 2006 toyota 4 runner v6 2wd its getting to be that time to change the fluid and ive notice its starting to make some noise so i am wanting to go ahead and change it. Now here is where I am a bit confused. what gear oil should i use and what weight should i use. I have some 75w-140 but it says heavy duty use and i do tow a 20ft boat so would this be a better bet? Or should i go ahead and put the 75w-90 that it calls for? My next question is should i put an additive in as well. I have read that toyota 4runners use the brakes to help with wheel slip instead of a locking diff not sure how true this is, any advice would help thanks!!
( I have looked around the form and nothing really helps answer this particular question)

 

[m85476585]

My next question is should i put an additive in as well. I have read that toyota 4runners use the brakes to help with wheel slip instead of a locking diff not sure how true this is, any advice would help thanks!!
( I have looked around the form and nothing really helps answer this particular question)

I would go with the recommended viscosity, or close to it. I used Mobil 1 75W-90 with no issues.

No limited slip additive is needed. The differential is a regular open differential, but the computer will apply the brakes to control a spinning wheel. That will only happen on slippery surfaces, like boat ramps, snow, or uneven trails. It works incredibly well in my limited experience.

 

[fdbyrne]

The manual in my 2004 called for SAE 90 gear oil which is nearly impossible to find. I went with 80w-90 in the rear and 75-90 in the front and transfer case.

 

[saabpowered]

I would also like to add that the rear end howls. it has done this since i bought it. i do have an a/t tire on it but i have noticed that it howls more when i first drive it but after a bit it does quite down. any ideas what this might be?

 

[RPS13]

Could be a crushed pinion bearing spacer. Happened to me as well. The bearing then loses preload and it gets eaten up and makes all sorts of noise at different speeds.

I run 90W-140 I think in the rear end because it gets down to like 36 deg F maybe a few times a year, otherwise it's hot. No mileage hit, and it does tend to drown out a little bit of gear noise you get with lots of power and some of these trucks. Gears are adjusted right, if a bit on the loose side of backlash (better lubrication when towing), but it gives out just a hint of gear noise. Most people can't hear it even after I point it out though, so maybe my wife is right and I'm crazy.

 

[smokey73]

by all rights, the 75w-140 will work. The book recommends 75w-90 and that is what you're "supposed" to use. I would assume that they recommend that weight of oil, mostly based on fuel economy numbers more than anything. The 140 oil will be thicker when it's cold, but at operating temp, they will both be pretty close to the same viscosity. In the end, it's your car, and your decision. Check the plug when you drain the oil. There will be metal stuck to it. If it's more than just a paste when you wipe it off, you might have a bearing letting loose. You don't want to see any chunks

 

[Top Shelf Synthetics]

I have been using Amsoil Severe Gear for 8 yrs now in my '03. Works very well in Arizona heat, I recommend it. Here is a link if you would like to learn more. AMSOIL Severe Gear® 75W-90 No additive needed.