Beltbuckle Bill

Hi everyone, I have a 2010 Sierra 4.8L 2wd 4L60E that is having problems. Details as follows -189,000 km - I bought the truck with a freshly rebuilt transmission with paperwork to prove it. Work was done by local tranny shop -190,000 km - lost 2nd gear completely, taken to repair shop to be repaired under warranty. Once repaired truck had a very harsh 1-2 shift for a while but slowly mellowed out to what I'd call normal. Drove fine like this until now -195,000 km - lost 4th gear completely, 2nd gear slipping under heavy throttle. Slips even more when put in manual 2nd gear I drive like a grandpa and don't beat on the truck at all. I don't have a scan tool to check if it's commanding 4th shift but I'm guessing that's not the problem anyway. Based on some research I'm leaning towards a cracked servo piston/bad seal but need someone knowledgeable to chime in. Also curious how the harsh 1-2 shift factors in to all this. Thanks! Tom

Here's one for you guys. I'm having a hard time diagnosing this sound and am really hoping someone can help. I have a 2010 Sierra 1500 with 4.8 and 4L60E, 2wd. I've never heard a sound like this come from a vehicle before. It sounds like a massive old wooden door groaning. Not a squeak but a low guttural groan. Here are the symptoms -groan when accelerating hard off a stop, through 1st and a little into 2nd -If I'm light on the throttle taking off it makes no sound -truck in drive, foot on brake, it will groan when given gas -no noise in reverse -no noise at speed -different rpm does not change the sound it makes -might be worth noting I have what I think is excessive driveshaft rotational play when parked. Like it can be rocked back and forth too much. U joints appear good Something is not happy when the powertrain/driveline is torquing up