Does differential oil really need to be changed?

Most differentials need a fluid change at about 50,000 miles. If left too long or if the fluid starts to run low, the differential will become noisy and can eventually fail. If that happens, the gears can seize, locking up the rear wheels and potentially causing a lot of damage or even an accident.

How much should it cost to change differential fluid?

Differential Fluid Change Cost Changing differential fluid isn’t too expensive. The fluid itself can cost between $30 and $80, and labor will run between $40 and $70.

What kind of oil do I put in a rear differential?

There are two types of differential fluid. One is mineral oil, which is a natural, crude oil-based fluid. The other is synthetic differential fluid, which is created in a lab. As with all synthetic oils, synthetic differential fluid oils can be fine-tuned for optimal performance.

What is the standard SAE oil use in differential?

For example, most modern gearboxes require a GL-4 oil, and separate differentials (where fitted) require a GL-5 oil. While they take the same form, the viscosity grades for gear oils are on a different scale than the viscosity grades for an engine oil. The viscometrics for gear oils are standardized in SAE J306.

How much does it cost to change the rear differential fluid?

You could have a quick lube place do the same thing for about $160-$180. Or as you said do it your self but there is probably no drain on the rear, have to suck it out. The fluid is probably 75w-90 in front and rear, maybe 80w-90, and ATF in the transfer case.

Does 2007 Tahoe have a rear main seal leak?

I have my 2007 Tahoe in the dealer now for a rear main seal leak, and a pinion seal leak. Both are covered under warranty. They told me that I should probably change the front and rear diff fluid, as well as the Transfer Case fluid while it is in there.

What type of fluid does the front differential take?

The front and rear differential takes synthetic gear oil, the transfer case takes about 3qt of Auto Trak II fluid if you have an auto 4WD button, or ATF if you do not. You can tell by the fluid color, Auto Trak II is blue and ATF is red.

What is the PN number for rear differential fluid?

The differentials in the GMT800s and 900s are both lockers and limited slip. That bulletin you posted Ted is probably for something else, the weight of fluid is not what’s in the manuals. The PN# for the rear diff fluid in 2005 was 12378261 and the current numbers are posted above and also 88900401.