Long Life Diff Oil

[Kushog]

I have the long life diff oil in my 2008 Sierra Crew 4x4, at what kms should i change the diff oil?
Rick

 

[dirtclod]

Petroleum/chemical engineers have access to volumes of test data that most of us can't get or understand. One of them can answer your question. As for me (Backyard mechanic), dirty oil is doing its job, that's why it got dirty. But I don't like looking at dirty oil. So I cut the suggested manufacturers mileage in half. A 6,000 mi oil change, will be done at 3,000. But I must confess. I rarely change differential fluids, unless there's an issue. Yes, that is overdoing it.

 

[Z15]

Define long life? I don't trust the oems to place the best products in the vehicles when new so I change all my gear lubes within the first 5,000 and use the best synthetic. I have lot of $ invested in my GMC and Cadillac and I will never cut corners on cheap lubes. I have been using synthetics for over 30 yrs.

Stop Changing the Oil Every 3,000 Miles Already!


The idea that the oil must be changed in a car every 3,000 miles or three months is a myth that even Jiffy Lube admits is not true. Nonetheless, the majority of drivers still insist on changing the oil more often than necessary, prompting the state of California to launch an initiative to clue car owners in as to what’s best for automobiles, the environment, and consumers’ pocketbooks.

In all cases, the answer boils down to this: For today’s cars, it’s almost never necessary to change the oil every 3,000 miles.


[portion gaped]


Why do drivers insist on changing the oil so frequently? Basically, they don’t know any better. After years and years of marketing messages have pounded into drivers’ psyches that an oil change every 3,000 miles is a rule that must be obeyed, it’s become a habit—a bad, unnecessarily expensive habit.

re: http://moneyland.time.com/2011/12/19/stop-changing-the-oil-every-3000-miles-already/


2010 GMC Sierra ECSB SLT Z71 All Terrain
2009 Cadillac CTS4 Performance Sedan

 

[leftrightother]

I have the long life diff oil in my 2008 Sierra Crew 4x4, at what kms should i change the diff oil?
Rick

I have a GMC 07 and the service book says 50,000 miles or 80,000 km. I did my whole drive line when I hit that point cause the book says all items are due then. (Transfer case, rear diff, and Auto trans. Manual trans fluid isn't due till 150,000 Miles.) The way I look at it I put it in the shop get them to change all the fluids at the same time and I am good for another year. (I do a lot of driving)

I would also do as Z15 said and have synthetic fluid put into the rear diff since that is what GM says has to be in there. (At least it says that in the 07 owners book.)

Remember it is better to change it then not to, cause it's not cheap replacing a rear end.