2016 GMC 2500 6.0

royg6677 · September 15, 2017

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 · September 16, 2017

Will be waiting for the test outcome results.

The test methodology is on track to diagnose properly. I still worry about your 85.15% load factor without calculated wind resistance drag. The trailer they will be using will be much closer to the 50% load factor to see operational outcome.

If the jerking is still present at the new lower load, head for trans torque convertor clutch solenoid engage / disengagement "mechanical operation". If the problem disappears, it's the truck being over the maximum tow capacity with all the drags added on, that have not been calculated.

Too bad you never scaled (full tank of gas) the truck / trailer for full loaded weight. That can be found at truck stops, moving companies and metal scrap yards. Some of these places have "truck scales". You'll be shocked at what your true actual weight will be.

2016HD · September 17, 2017

It does not Matter what the frickin wind resistance and or load on the truck is. Weather it was at maximum load or 50% Load. The truck should pull and or shift correctly. Im sure there is a programming glitch or he ended up with a bad converter solenoid!! Stop trying to over diagnose a simple problem! Im sorry but most techs and dealerships have no idea how to diagnose a mechanical problem anymore. They look straight to trying to avoid warranty claims or electronic programming and electronic failures. Im betting this problem can be duplicated without a load on the truck. If not its an easy read while driving the truck and connected to a diagnostic scanner.

I dont care if the truck was in a 100mph head wind and had been overloaded buy 50%. Has nothing to do with what the transmission and or converter is supposed to do.

OP. please keep us updated on the problem. And sorry if i missed it but if you shift down and apply more throttle does the issue go away? 2000Rpm while under a heavy load is not the correct rpm to be trying to pull at. Make it eat and shift into the correct gear and bring the rpm up over 3000. then once up to cruising speed you should beable to cruise on flat ground in 5th with that weight.

grizzlyltz · September 17, 2017

It does not Matter what the frickin wind resistance and or load on the truck is. Weather it was at maximum load or 50% Load. The truck should pull and or shift correctly. Im sure there is a programming glitch or he ended up with a bad converter solenoid!! Stop trying to over diagnose a simple problem! Im sorry but most techs and dealerships have no idea how to diagnose a mechanical problem anymore. They look straight to trying to avoid warranty claims or electronic programming and electronic failures. Im betting this problem can be duplicated without a load on the truck. If not its an easy read while driving the truck and connected to a diagnostic scanner.

I dont care if the truck was in a 100mph head wind and had been overloaded buy 50%. Has nothing to do with what the transmission and or converter is supposed to do.

OP. please keep us updated on the problem. And sorry if i missed it but if you shift down and apply more throttle does the issue go away? 2000Rpm while under a heavy load is not the correct rpm to be trying to pull at. Make it eat and shift into the correct gear and bring the rpm up over 3000. then once up to cruising speed you should beable to cruise on flat ground in 5th with that weight.

I agree 100%

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royg6677 · September 17, 2017

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.

2016HD · September 17, 2017

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.

Thanks. This is what i figured. And should be an easy resolve for a good tech with a scanner. Really sounds like an update is needed. Or you have a miscommunication between pcm and tcm while under load. Wasnt blaming that you were babying the truck. Just looking for the throttle an rpm situation. Either that or the converter solenoid is sticking or faulty etc. Does the truck do this while its in Tow/haul mode as well?

Edited September 17, 2017 by 2016HD

sdeeter19555 · September 17, 2017

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.

This is why I think it's the transmission's clutches...not enough to pressure to keep them tight.

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2016HD · September 17, 2017

This is why I think it's the transmission's clutches...not enough to pressure to keep them tight.

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Gm had an issue with the 2014 and earlier trucks occasionally having a torque converter shudder problem while under load. Pretty sure a recall. was issued for the TCM to be reprogrammed etc. I Dont remember the whole issue. Have not seen it with the 2015 + trucks. But it is probably the same situation.

sdeeter19555 · September 18, 2017

Never had a recall, and mine is a 2012...

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royg6677 · September 18, 2017

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.

4wdriver · September 19, 2017

Sounds like the old how many times can we make a guy come by here before he gives up.

royg6677 · September 19, 2017

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.

4wdriver · September 19, 2017

Hopefully the problem is identified

royg6677 · September 21, 2017

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.