Hi Scotty. I have a 2004 GMC Yukon XL 5.3 with 219,000 miles. Consistent oil changes have finally removed the sludge in the dipstick tube, and I no longer have to guess now. Problem is, now I realized the transmission is overfill massively high. Guessing about 5 quarts overfilled minimum. It's been like this for over a year, and just now. My father doesn't know what to do, but it's dirty looking. I don't know if it's dirty from being over the service interval, or if it's metal shavings from all that pressure. Having differential serviced with it by an actual mechanic that I personally go to, not chain store again. Should I chance it with a full service and throw some Lucas Trans Slip in? Thanks!