Changing Gear Oil -- Close enough?

[Bean Counter]

What do you need?
I used my mad rocket science skills to find them online.

1st gen Tundra and/or Sequoia. Need to do both. is that what you posted?

Thanks!!!

[jackelope]

What do you need?
I used my mad rocket science skills to find them online.

1st gen Tundra and/or Sequoia. Need to do both. is that what you posted?

Thanks!!!

That was for a 2003 Tundra. Honestly I don't know what gen is what.

[Bean Counter]

That'll work! Here goes nothin'..   

Close eyes + slam trigger! 

[thinkingman]

I just completed my gear oil change.
20 minutes start to finish.
Red Line MT-90 75W90 GL4 seems to be exactly what it wanted.

[Jason]

A week ago I changed the engine oil in my 02 Tundra and accidentally put in 5w20 instead of 5w30, so before I ran up and picked up the right weight oil I called and talked to a tech at my local Toyota dealership and he said I was fine running the lighter oil in the winter..hope this true?

[jackelope]

A week ago I changed the engine oil in my 02 Tundra and accidentally put in 5w20 instead of 5w30, so before I ran up and picked up the right weight oil I called and talked to a tech at my local Toyota dealership and he said I was fine running the lighter oil in the winter..hope this true?

Manufacturer doesn't specify that that is acceptable, but I imagine you're ok, especially in the cold weather.
I wouldn't do it in the summer time/hot weather.

[syoungs]

I could be wrong, but at least in fords, running without the friction modifier is terrible on the limited slip if equipped.

I try to stick to manufacturers guidelines on fluids, race cars might run synthetic in everything, but even running as hard as they do, they don't run as long between rebuilds ( least none of them that I know do)

[Bean Counter]

I bought the friction modifier for this go around. Thanks. However, in 60,000 miles I didn't have any problems with just the synthetic 75w-90 even in this hot desert I live in. But I don't tow or even have a heavy payload hardly ever. Would it be worse to switch back to conventional now that I'm running synthetic?

[syoungs]

I don't know if there's a conclusive answer for that, I would do it.

I know a lot of people say not to change to synthetic if it'd high mileage, cause it'll cause leaks, which I don't buy. If the seals are in good shape, they won't leak. Seals not leaking much, will leak more with synthetic though.

[Bean Counter]

Remember I'm talking about gear oil in the differentials

[syoungs]

Yep. Still seals in there though 

[Rick]

You can switch between conventional and synthetic without issue.

[Rick]

A week ago I changed the engine oil in my 02 Tundra and accidentally put in 5w20 instead of 5w30, so before I ran up and picked up the right weight oil I called and talked to a tech at my local Toyota dealership and he said I was fine running the lighter oil in the winter..hope this true?

You're fine. 5w-30 would likely shear down to a 5w-20 by the end of the oil change interval anyway.

I'd have zero issue running 5w-20 in the summer.

[thinkingman]

Go back to Dino oil with the friction modifier.
You'll be fine.

[Night goat]

synthetic oils  and seals dont get along very well, some seals hold up, but, whenever I switched to synthetic, I started getting leaks, and when they start, they dont stop

might be worth researching what oils you have been using and how the recipes have changed over the years, I know that Delo switched up thier recipe with their 15-40 oil, we stopped using delo at work because it is just too dry of an oil, we switched over to a 76/conoco phillips oil. for all the emmisions regulations, oil isnt what it used to be, since most oil for diesels have gone to a low emission formula, they omit zinc, phosporus, lead, and various other lubrication compounds

gear oil on the other hand, as it is not in a crank case, hasnt changed. I would presume that the lower the opperating temperature of a part the higher the viscosity you would want, which might suggest why the lube in the front diff is thinner than the rear diff to compensate for engine heat.

in a crank case, oil needs to be thin to flow, in a cold gear box, oil needs to be thick to stick and provide static lubrication, as a differential or some gear boxes have the gears partially submerged in lube.

the lighter oil in the winter is correct because it compensates for an ambient temperature diference, and being thinner, and colder outside, it takes less to heat and flow properly, compared to using a light oil in the summer, it would be too thin to properly lubricate, whereas a heavier oil will compensate for summer temperatures and provide correct lubrication.

the US Army did a study on motor oil and concluded that motor oil does not break down or otherwise "go bad", however what makes a motor oil "go bad" is contamination with acids, fine particulate matter such as metal wear, and soot, I recently installed an oil bypass filtration system that is supposed to filter oil so finely, it extends the service interval exponentially, to the extent that the company reccomends sending in oil samlles before doing an oil change, as depending on the level of contamination at a normal service interval, it will dictate 1) what is going on in the engine, and 2) whether or not an oil change is really necessary.

oil is pretty interesting