I have a 2006 Chevy Silverado 4x4 automatic transmission. It will only go in reverse, 2nd, and 1st. Wont go in drive or 3rd. i checked the fluid and it is fine. I'm going to get it to my mechanic. My question is would it be safe to drive it to the mechanic in 2nd gear or should I get it towed. Mechanic is about 20 miles away. If it is safe, at what speeds should I maintain?
This is a pretty common malady for the 4L60e transmission in GM trucks of this model. IIRC, the problem is most likely the sun shell is broken. If you were a mile away, I'd suggest you could drive it. Since you are talking 20 miles, the fastest you could drive it (reasonably) without causing issues for your engine would be about 20mph. That would mean it would take you about an hour to get there. By doing that you run the extreme risk of damaging the transmission further. My suggestion to you is to get it towed.