Sign up for FREE! Become a GM-Trucks.com Member Today!
In 20 seconds you can become part of the worlds largest and oldest community discussing General Motors, Chevrolet and GMC branded pickups, crossovers, and SUVs. From buying research to owner support, join 1.5 MILLION GM Truck Enthusiasts every month who use GM-Trucks.com as a daily part of their ownership experience.
How's it going , new to forum and hoping someone could shed some light. I have a 2019 silverado custom 5.3 w/ 6 speed trans with about 37k. A month ago the truck threw error p0741, it would Rev high and not want to shift so dealer replaced tcm and new fluid. A few weeks past and code comes back with trans temp running around 215* when it did so dealer replaced torque converter and said it was good to go. I took for a extended drive of so.e city and a Lil hwy for around d 1hr and Temps climbed to 225*. Is 225* high? Doesn't seem normal and dealer is saying they. Ant find anything wrong
Ok so I have a 2015 gmc sierra 1500. after backing up and putting it into drive I get going for about 5 to 10 seconds ill get a jarring lock up for a split second. First time it happened I was going about 40 and I bounced off the steering wheel and left a little skid mark. It sounds like either my transfer case or transmission is locking up but it literally lasts for a split second then goes away. also I've noticed that after shifting from reverse I hear a loud transmission whine before it does it. This has happened at least 30 times for about a year and dealer says they can't recreate it.
It's the 6spd tranny
Also I know all about the normal GMC transmission clunk when shifting I have that too but I've learned to live with it. This is something else entirely. Its dangerous and I can't find anything on any forum mentioning this issue
I have a 2004 Chevy Astro van 2WD 4.3L with a 4L60E automatic transmission and something is seriously wrong, but I have yet to figure it out. I definitely need some help. I usually do all my own repairs and I am very mechanically inclined, but this has me stumped. I even consulted a friend who knows a lot more than me and he was puzzled and asked that I share with him what was wrong once it has been diagnosed. I would probably be willing to drop the big wad of cash down for parts for a remanufactured transmission if needed, or for a remanufactured rear end and new axles.... BUT the van is not worth spending $1,500 (or more) times TWO. I need to definitively be able diagnose the problem so that I can decide how much I'm going to have to invest to get it going again. I bought it used from a municipal police department that used it as a crime scene investigation vehicle and it has no hitch on it, so to the best of my knowledge it has never done any towing. Here is what happened and what I have checked thus far....
I pulled out of the driveway at work and after I had cleared the 2 lanes of oncoming traffic and was in the crossover in the median I let off of the accelerator and heard a slap, pop, or bang that sounded like it came from the right, rear corner. I instantly thought it might be trouble as it sounded like clapping/slapping two solid bricks together. I hoped it was just something I ran over. Then I pulled out and accelerated up to 55 mph. Then about a 1/2 mile down the road I heard what sounded like driving on a tire that was completely flat. I pulled off the road to check out my tires. I was surprised when they all looked fine. I realized something had to be wrong and I wanted to get my van to a better spot where I could investigate further. I put it in reverse to back up a few feet to better align me with the area I wanted to drive to, but the van would not move backwards. I wondered if something with my rear brakes had broken or locked up. I was able to move forward in D, but there was a good amount of resistance as the engine was struggling to move the van forward. There was a good clear spot nearby where I parked.
I thought somehow something had broken in the rear brakes and bound things up preventing the van from moving as normal. I jacked up the van and removed both of the rear wheels, removed the pads & rotors, then propped the calipers out of the way. I put the transmission in neutral. I replaced the rear wheels as it was easier to rotate the tires by hand than trying to rotate the lugs on the hubs by hand. The tires spun freely by hand, but after about 10 revolutions there was a clang noise and the tires stopped. I rotated the tire in the reverse direction and it no longer made the driveshaft move as it had been in the forward direction. Then the clang noise again and the tire stopped rotating in the reverse position. Both front wheels easily rotated when spun by hand, so the binding wasn't coming from the front
This made me think that it was possibly something going on in the rear end. I pulled the cover and I saw no obvious problems with the differential. I have the G80 rear end which I had never seen that type of rear end before. When I moved my tire forward by hand slowly there was no movement in the rear end, but when I put my foot on the tire and give it a spin the tire moved a lot and the rear end moves a little. I didn't see anything that looked worn or damaged in the rear end. I cleaned up the parts, cover, and magnet and put the cover on with a new gasket and replaced the fluid. While both the rear wheels were still off the ground I cranked the van. It was still in neutral, but both rear wheels were slowly rotating forward. Then I shifted into Drive and, with the engine idling, the wheels would pulse several rotations forward, then slow to almost a stop and then repeat the pulse & near stop. I couldn't understand why the surge and slow was taking place. Then, I drove it the 1/2 back to work to leave it in their parking lot. The van made all sorts of popping, grinding, and clanging noises. When I stopped I put the transmission in neutral, but it would not roll backwards. I tried reverse and the nose of the van dived down and the rear bucked up, but the van never traveled any distance in reverse. I pulled it forward a few feet into the nearest parking space. The van did throw a MIL code on the way back to work, which was a P0756 (PCM sensed an irregularity in shift solenoid B).
I thought that I might need to remove the driveshaft and see if the transmission would turn the output shaft while in reverse. Also, I could try to see if there were and weird noises, pulsing, or resistance to the output shift turning when in Drive. But, I wouldn't necessarily know for sure the tranny was good if it only misbehaved while under a load.
I had ordered a set of shop manuals about a week before all this happened, and they have now arrived but I wanted to see if anyone had any ideas about how to diagnose my problem before I resorted to the shop manuals. I get bogged down in them because there is soooo much information in them.
How can I definitely determine if the problem is my tranny, my rear end, or both?
Here is a video link on YouTube showing when I had the rear end cover removed:
Here is a video link showing when the rear end cover and fluid were replaced and both rear wheels were off the ground in Neutral and in Drive with the van running:
I dont know if this allowed in here but i will soon have some 2020 RST factory 20inch take offs wrapped with nitto ridge grapplers in 275/55/20 with more that 50% tread left that i wont need as i will be getting new wheels and tires soon. Anyone in GA interested? New the rims are 395 from Detroit wheel and tire website may be cheaper somewhere else let me know. And Nittos new are 1000. So all new this is a 2600 dollar package not to mention TPMS so i will consider taking 1700 for the set. Sorry i dont feel like shipping out of state unless you do all the leg work and tell me where to take them to drop off within reasonable distance to me.. Atl area..... Otherwise i can meet half the distance between me and you. We can work out details if interested.
Recently Browsing 0 members
No registered users viewing this page.
Who's Online 54 Members, 0 Anonymous, 2,586 Guests (See full list)
- Derek Klein
- Ryan Gauder
- Ricky Jordan
- Paul 2020RST
- Gray Fox
- Logan Russo
- Stephen H
- Jim Johnston
- Super 8