Changed all diff fluids, does this seem right?....

[camshaft]

So I spent the day changing all the fluids on my 05 CC 1/2 ton. It has about 20000km and I feel bad about not changing the fluids until now (other than oil), but I was pleasantly surprised with the little amount of metal fillings that actually came out of the front and rear diffs.

 

I used about 1.75 ltrs in the front diff. Almost 2 ltrs of Autotrak 2 in the transfer case, and about 2.25ltrs in the rear diff. The diffs received royal purple fluid. I was surprised that only about 1.75ltrs of rear diff fluid came out. Is this fairly common for GM to be this low in the rear diff?

 

I filled the rear up to about 3/4 inch below the fill hole.

 

I was just curious as to if my amounts were fairly consistant with everyone elses, that's all.

 

Plan on doing the tranny w/ mobile 1 in the near future.

[rjirvine]

Thats about what I put in my 2000 Silverado 4x4. Good luck with the PITFA tranny bolt.

[pm26]

So I spent the day changing all the fluids on my 05 CC 1/2 ton.  It has about 20000km and I feel bad about not changing the fluids until now (other than oil), but I was pleasantly surprised with the little amount of metal fillings that actually came out of the front and rear diffs.

 

 

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Actually, you changed the fluids in the differentials and transfer case way too early. Even with severe service, such as frequent off-road use or pulling heavy trailers, you do not need to change the fluids before 30k miles (about 45k kilometers). With normal service, 60k mile intervals are plenty.

[asilverblazer]

Atleast with changing them early you can get the "break-in" trash out of the diffs, after that the 30K interval is fine.

 

Ideally I would like to change out all the fluids, after about 5K, or after the first few heavy tow/hauls... That would get all the assembly junk and break-in material out, after that I would expect to see very little material in the fluid, even after 30,000 miles.

[snoman]

Actually, you changed the fluids in the differentials and transfer case way too early.  Even with severe service, such as frequent off-road use or pulling heavy trailers, you do not need to change the fluids before 30k miles (about 45k kilometers).  With normal service, 60k mile intervals are plenty.

 

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There is not such thing as changing it too early if you plan to keep it a long time and actually the diff lube should be changed within the first 1000 miles or so if you plan to tow to get breakin grit out of it. While a lot of people do, you should never tow on a new axle for about 1000 miles and you should change the lube too (same with engine) it will not make much differenc if you plan to trade it every few years or so but it will if you plan to keep it a long time like I do.. Also if you tow a lot, 30K mile is too long to leave fluid in there.

[camshaft]

I changed the engine oil at 800km, and only tow a 1500lb tent trailer. So I dont feel too bad about leaving the diff until now.

 

But I totally agree, you cant change oils too soon or too often enough.

[pm26]

IBut I totally agree, you cant change oils too soon or too often enough.

 

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So why not do it every 100 miles then?

 

Actually, you can easily destroy both your differential and transmission if the oil gets excessively hot. Changing the oil, no matter how often, will not make any difference in such case. A good aftemarket finned aluminum covers and larger transmission oil cooler and oi temperature gauge will do a lot more for you when towing heavy loads then very frequent transmission fluid and differential gear oil changes.