Please fill out the following to ask a question. MAKE:Oldsmobile MODEL:Silhouette YEAR:2001 MILES:215,000 ENGINE:3.4L DESCRIBE ISSUE....I have a customer with an '01 Silhouette (4T65-E) that won't fully shift into 4th gear. It will "hunt" for a few seconds and then drop back into 3rd. The only code is P1811 - maximum adapt and long shift. Naturally, the first thing I did was to drop the pan, change the filter and refill. When that didn't work, I sent him to another shop with a flush machine and had it fully flushed. Still no change. I don't get why a line pressure problem would only affect the 3-4 shift and not any of the others. I'm tempted to replace the 3-4 shift solenoid but don't want to give my customer any false hopes if that doesn't have any chance of fixing the problem. Like I said, the trans seems to perform just fine until it wants to shift into 4th. Thanks in advance for any suggestions.