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Showing results for tags 'hard shift'.
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09 Silverado Hard Shift
Russell Brandon posted a topic in Gen III and IV Small Block & DrivetrainMy 09 silverado 5.3 4x4 has shifted hard into 2nd and some into 3rd for several years now. A few months ago I decided to fix it. Codes were for transmission control solenoids, module, oil pressure sensor, misfires...etc. codes like P0700 P0717 P0521 P0523. I replaced all 3 shift solenoids, oil pressure sensor, and immediately the truck shifted like new again and it lasted for a few days or a week. And it started shifting hard again. Really hard. It's so frustrating. And it's throwing all the same codes again. Recently, my truck started misfiring so badly the entire truck was shaking. It was running on two cylinders. All of the ignition colis were failing all at once and the truck was not drivable. Btw, I just changed out those ignition coils, plugs and wires just two years ago, all Ac Delco plugs/wires and duralast ignition coils. So anyways, I replaced all of the coils plugs and wires again this week and the engine no longer misfires, running on all cylinders again. And for a few hours after, there was zero hard shifting now. It was running great, like new again. Shifting smooth as could be. But after making it into the city and hitting traffic lights and stop signs, it didn't take long for the very hard shifts to come back. I've read on this and have been dealing with this in time and parts for so long now. I've read about ground wires could be the cause of all of this. I have replaced everything the computer has suggested, and for a short time after the repairs, the truck would run like new. But the hard shift always comes back. I know there's people out there that have had this same problem. I've read a lot about it but without actually finding the grounds for these specific sensors, I've hit a dead end. The issue just keeps coming back as it's obvious there is a root cause I am not getting to. Please share any knowledge or experiences on this topic. And any knowledge of the location of these grounds may be at. Thank you!
I am having two issues with my 2000 GMC Sonoma 2.2L 2WD single cab pickup truck. It has the 4L60E transmission in it, which is what is causing issues. It currently about 146,000 miles on the truck itself, but has a rebuilt transmission in it with about 60,000 miles. The reason I replaced the transmission the first time was because it wouldn't shift out of first gear and there was a loud cranking, grinding sound. Reverse also wouldn't work. I first noticed issues with the original transmission during a 400-mile road trip across generally hilly terrain. I wasn't towing anything, nor was it loaded with much except a large suitcase and my wife and I. About midway through the trip (traveling 60-70 mph), what I believe was the TCC failed to engage. I'm a complete noob when it comes to transmissions and TCs, but research on the web led me to surmise the TCC was the issue. As I was in the fourth gear, the RPMs jumped up from 3k to 4k, with no change in the accelerator position. I was not at WOT. The tachometer would remain at the higher RPMs for about 30-60 minutes until it would randomly drop back down to the normal cruising rate. This cycle would repeat multiple times throughout the trip there and back. Not realizing there was a major issue (and being pretty broke), I didn't have my truck checked. About a month later, the transmission did the grinding, clanking sound and went caput. That's when my mechanic recommended a transmission replacement. That was about six months ago.Two weeks ago, I took a job that requires me to travel about 20 minutes on a 70 mph interstate to get to work and back. I also drive the entire time throughout my 8-hour work day. The temperature outside has been nice (70-75 degrees), and I'm never revving the motor past 3k RPM. So that's the history. Sorry for the lengthy explanation. I wanted all the facts in there. Here's the two problems I'm encountering. 1: Hard shift into second gear. The transmission jerks when it shifts into second gear, but it doesn't happen all the time. It seems to happen after I drive for a while, or travel at interstate speeds after cruising around town for a bit. The odd thing about this is that when I turn off the truck and let it sit for about five minutes, the problem disappears, and doesn't return for more than an hour or two. When it happens again, I just park, turn off for five minutes and continue on until the next time it begins shifting hard. 2: TCC disengaging again on interstate. This has only happened once and it was today. But I don't want to destroy another transmission waiting to figure out the issue. I was traveling home, and at about halfway through the trip of 20 miles, the RPMs jumped from 3k to 4k at a cruising speed of 68 mph. Again, there was no change in the accelerator and I wasn't running WOT. But I had driven the truck for about six hours straight (minus a stop here and there for restroom, lunch, etc.). When I got off the interstate, the hard shift into second was even more pronounced. I then pulled into the nearest parking lot, let the truck sit off for five minutes, and the problem vanished. Side note: The SES light came on about three weeks ago, stayed on for three days and went off. Earlier this week, the light came back on. I haven't checked the code yet. That's this weekend's task. I will update the post with the error code when I get it. Soooo... Anyone have a clue what's going on? I sure don't.
Have an 06 2500 HD. Transmission will drive all day long at speeds under 50 mph and never shift hard. If I drive 7-8 miles at 65-70 mph, like on interstate, once I slow down and stop and start again, tranny will shift hard between 1, 2 and 3rd. Once I park it for 15 minutes, it's back to normal and no hard shifts. Tran temp gauge does not indicate any overheating.