Review on Enhance Transmission Performance with GM Genuine Parts 29535617 Automatic Transmission Fluid Pan Magnet by Michael Crossman

These are the updated magnets for the 4T65E gearbox. You need two of these. One goes into the steel pan and the other goes to the filter. The original magnet is pathetic, like a cheap plastic laminate fridge magnet, and gets saturated with metal shavings very quickly. Unfortunately, the filter doesn't catch these shavings, and they clog the transmission oil, allowing some of them to circulate. This causes the PCS to drop line pressure, causing your transmission to appear to slip. The transmission then gives code P1811 and shifts very hard. Also, during normal driving, the transmission fluid can begin to overheat, reaching approximately 230 degrees Fahrenheit or more. I had the exact same problem: my gearbox didn't dare to change gears, it seemed to slip a lot and overheated during normal driving. However, the liquid did not discolor and did not smell burned. I dropped the pan, put in those magnets and flushed the cooling lines with Kooler Kleen. I then went for a test ride and after a few minutes of riding, the shifting improved dramatically to normal. I drove it until it was up to operating temperature and saw that the fluid no longer overheats. This most likely happened because the radiator was flushed with Kooler Kleen. Try this solution if your 4T65E transmission seems to be slipping but the fluid color is normal and does not smell burnt. Most likely this will solve the problem. I also recommend flushing the coolant lines with Lubegard Kooler Kleen to remove swarf from the coolant in the radiator. If you have overheating problem, this might solve it. If it doesn't, you may need a new transmission cooler/cooler, or your TCC relief valve may be defective and need to be replaced. The Kooler Kleen universal tip is only available from O'Reilly Auto Parts and fits flush lines.