my 2500 silverado runs at 2600 rpms to hold 60 mph, is this normal?
Sounds like tow/haul mode is on. Tow/haul does a lot with the vehicle including preventing your truck from shifting into overdrive so your transmission isn't constantly gear hunting on the highway. Look for an orange light that looks like a trailer on the cluster. The button should be on your shifter and chances are ur hitting it without realizing it. Whether this is happening or not the problem is your truck won't shift from 3rd to 4th.
Could be the TCC (Torque Converter Clutch) selinoid sticking. That will also prevent the transmission from shifting into overdrive. HTH. -Jim
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