The dealer run lube center is telling me I need to change the front and rear diff lube ,because I have 24000 miles on my 2007 Sierra 4 wd. This seems like a bit too soon . Any opinions ?

DLJ

 

There should be a suggested service interval in your manual. What does it recommend?

 

Thanks for replying,the manual has intervals for everything but the differentials. I'll check with a different dealer.

Thanks again DLJ

 

Im gonna say its every 15k.

 

My Chilton manual only goes up to 2006 but it says to change every 60,000 or 48 months, but it has a side note and it reads - Perform this procedure at half the recommended interval if operated under one or more of the following conditions...
...in heavy traffic where outside temp regularly reaches 90 degrees or higher
...in hilly or mountainous terrain
...frequent trailer towing
...if the vehicle has been driven through deep water

 

Yeah it could be that too. Really though you wanna change it if its past the time with not as many miles on it. The fluid will collect condensation overtime. Just like the oil in ur motor but it is set up with PCV to the intake to suck out the vapors of moisture to keep from building up inside the motor. That is why some rear diffs have ventilation tubes. So it is safer to change it anyways when in doubt, IMO.

 

I just changed mine at 173,000 miles (99 Sierra 3.73 gears) and it didn't look that bad when I took it out - I tow a 3500 lbs bass boat all summer, and thought it would be ugly. Replaced with amsoil sever gear 75w140.

 

I don't think the differential oil need any changing for 10 years or more. I've taken axles apart that came from junkyards and the oil in them looked fine, and that was before the synthetic lubricants of today. I had over 180K miles on my 99 Silverado when I had to replace the parking brake assemblies and the oil in the rear axle was fine. I replaced it simply because I had to drain it out. It comes from the factory with a synthetic oil, so that should last you a lifetime. I used Mobil 1 gear oil for it. Gear oil is made to last and under normal conditions (barring water contamination), it can last a lifetime.