Quote:
Originally Posted by C66 Racing  All,
I changed out my factory fill diff fluid with AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 a few weeks ago, sampled the stock fluid and submitted it to Blackstone Labs. The fluid had 10,636 miles on it.
The results weren't good. Here is their quote:
"We normally expect to see high wear in factory fill differential sample, though these levels are a little excessive, even for that. Iron was the dominant metal and shows some serious wear at steel parts. Chrome, iron, and nickel are all alloys in steel, and should read well below average considering the short oil run. Universal averages show normal wear levels
after about 29,000 miles oil use. Copper, lead, and tin show poor wearing bronze parts like a bushing. Suggest having this oil changed out if you haven't do so already and resample in 5,000 miles."
You can see the full report on this page of my dealer website: 2006 Cadillac CTS-V Used Oil Analysis Factory Fill Differential Fluid
My recommendation for those that haven't changed out the stock fluid - change it early, whether you chose AMSOIL or another fluid.  |
I recently changed out, and saved, my factory fill at 13,600 miles. I have ordered the oil test kit from Blackstone, but it has not arrived yet. Although, it may be awhile (weeks) I will post my analysis when it arrives.
Based on the appearance of the fluid I drained, I believe it should have been changed it much sooner. Unless and until I see evidence that the rate of contamination has subsided (such as an oil analysis or visual inspection) I intend to change the fluid with each oil change.