Hmm. Yeah I understood it was uneven wear. So you are saying the culprit is the original ATF that Chevy used with the 8L90? And that replacing with the blue Mobil 1 as recommended is the hoped-for solution as, not being hygroscopic, it will potentially allow the clutch plates to start wearing more evenly, reducing deterioration and buildup of shavings in the fluid?
That re-tuning the transmission is not entirely necessary?
Quote:
Originally Posted by ctrlz
The shudder is not a property of the fluid. It is the result of uneven wear on the clutch plates. Once they are partially worn, and you replace the fluid, the hope is that they start to wear normally again and the bumpy bits even out. Let it go too long, and you can't reverse the process.
Normal transmission fluid has friction modifiers allowing the clutch plates to engage smoothly and then lock. The defective fluid is hygroscopic. The presence of small amounts of water interferes with the engagement of the plates, resulting in a slide-grab-slide-grab type of engagement. It's like putting a bit of dish soap on a slip-and-slide vs. just plain water.
|