How long before I can expect serious internal problems with 329,812 miles so far
You mean you haven’t yet? Sorry but I’ve never put that many miles on a vehicle. I’m honestly surprised.
About 7 years ago would be normally be “how long”. You are WAY outside normal for this SUV. Save your money for a newer SUV and drive on.
Could be tomorrow or ten years from now.
At this point, I’d rely on how often you’ve been changing the oil and other routine maintenance. Not changing the oil regularly is what slowly kills an engine.
Of course, stuff happens on even the best cared for cars. Such is life.
… and if the trans fluid hasn’t been changed 8 to 10 times so far, the transmission is actually well past being due for failure.
Yeah, I agree with the others. You are on very borrowed time with that thing. Count yourself very fortunate, but don’t expect the luck to last. Have replacement money ready to go.