royg6677

This past summer truck went thru additional testing replaced torque converter. All this testing and torque replacement did not fix problem. GM has decided to buy the truck back. I want to thank all that tried to help me thru this process. RRG

4wdriver The info they gave me is contained in Document ID 4530678. It refers to code P0777 firm 3-2 downshift reprogram TCM Jun 7 2016. I did not have any displayed codes that I know of I think they thought that this may help my condition. Service labor code 2810155 - Control solenoid valve and transmission control module assembly reprogramming with SPS.

It's been some time long story short the TCM update did not help at all. I will continue with dealer next spring when I have 5th wheel out of storage. I am going to replace slider hitch with a standard fixed hitch to see if that is at fault. I do not think that is the problem but I want to get to the bottom of this problem and not have the hitch be in question. Till next spring have a great Thanksgiving, Xmas and New Year.

Dealer called me and told me there is some sort of update to transmission I think TCM he does not think it will help but it goes in tomorrow for update. They are also doing to reset the shift learning ???????? Will let you know after my next trip 10/19 for 4 day.

After about 50 miles of driving and recording computer data the jerking/bucking continues. The unlocking of converter stops the bucking and when it is reengaged starts up again. They are going to contact GM and see if there is anything to do. They are to contact with results by end of week. My hitch may come into question. Service manager says that it is not a engine problem. Will keep you posted.

The service manager, one of the dealer owners and I did the test drive with the trailer and equipment approx between 10-11k and the truck did not jerk and buck. On Monday we will be doing the same with my 5th wheel camper. Will let you know the results of that test. I did the driving.

Dealer service manager called today they made arrangements with Penn Equipment to use one of their trailers loaded with a mini excavator to get total around 10K. I will be present when test takes place this Thursday. I think they are at least trying to determine whats happening to cause jerking/bucking.

Just got a call from dealer service manager saying they could not duplicate condition with there camper. I have a appointment the 25th to go with service manager and one of the owners and my 5th wheel for a test drive. 2016HD this happens in tow/haul mode in manual and drive.

2016HD If I get on it from a start no problem. It is after I am up to cruising speed that the problem starts. 5th gear cruising at 60 MPH is around 2100-2200 rpm. Giving it a little throttle to keep it going at 60 I am in the area where it starts jerk/buck. The truck runs fine if you put the boot to it. You do not have to have your foot in it all the time and this is when it shows up. Cruising and only needing a little gas to keep it rolling is the problem. I sure hope this puts a end that I am babying the truck. Not the problem period.

I do not know what the pin weight is. Advertised pin weight is 1880lb empty. I would guess that it is around 2000 - 2100lb. The test they are going to do on Monday are with a bumper pull camper around 7K. Another thing about the test that was conducted with my 5th wheel I was in manual in 3rd and 4th gear and when converter was locked and the tech unlocked it we were going up a slight grade to show him how it jerks/ bucks and this is not to be confused with chucking. I know the difference. It feels like the engine would be missing or cutting in or out. If the transmission is in 4th gear at about 50 mph the rpms are around 2100rpm if it 5th gear at about 60 mph the rpms are about 2100rpm. That is what is annoying trying to drive and increase throttle a little and truck starts to shake. Not cool RRG

Motor City Rick When I lightly pressed brake and was on gas at the same time and converter unlocked should i have noticed a slight rpm change? I did not notice any change at all. When I took test drive with service supervisor and he unlocked converter with computer jerking stopped and rpm increased. I guess I am lost. I also do not think I am over taxing the truck. It pulls just fine except for the jerking/bucking within the 2100 thru 3200 rpm range. I hope they find the problem It feels as if the engine is missing but they do not think it is the engine. RRG

Motor City Rick I just got home from a trip with camper and tried several time to just touch brake pedal did not change jerking or bucking within the RPM range mentioned. Thanks RRG

The jerking/bucking happens in at least 3,4 and 5th gears. I am not babying truck. I travel around 55 to 60 and if you check this is in the rpm range I talked to you about it is very annoying. I have to drive around in manual and shift to try to stay away from this situation.My truck is a 2016 GMC Sierra 2500HD DC 6.5 bed 6.0 410 gears B&W hitch and is stock with less than 6K miles. According to manual 5th wheel trailer Max weight 14100lb GCWR 21200lb Dealer called to bring truck in for testing again dealer owner has a travel trailer they want to test with. Will let you know the out come. Test date 9/18 Thanks all RRG

Motor City RickCamper loaded the way I am towing about 11200 lb I do not have any fluid in my tanks. What speed---It depends in what gear the truck is in. It does not happen at any certain speed. 2000 rpm everything ok in any gear from 3rd on at about 2200 on up jerking starts stops jerking at about 3200 rpm in the same gear you are in. On a level road on light acceleration increasing speed no jerking as soon as I reach around 2200 rpm it starts to jerk. Hope I answered your question I hope that I do not have to do what you are saying will fix this condition

I started towing a 5th wheel camper and experience a jerking in the truck in any gear above 3rd gear and between 2200 rpm and a little above 3000 rpm. If I manually down shift causing rpm to be above 3200 rpm and above it will stop jerking. I took truck to dealer with camper attached and duplicated jerking in the above mentioned rpm range, he had computer connected to truck and when he unlocked converter jerking stopped. He locked converter and jerking started again within the 2200-3000 range. GM and he does not think it is a converter is the problem still waiting for them to contact me. Has anyone had a similar problem and what was the resolve?