2014 3500 DRW Groan when loaded

[NickSullivan]

Hey All,
I loaded up our new camper, Arctic Fox 1150 and the horses this last weekend for the first time. The truck did great except one issue. While starting from a slow speed and then trying to accelerate up a hill the truck would shift to 2nd or 3rd, while at a low RPM and trying to build RPM and torque the truck would start to groan very loudly and it seemed to come from the back half of the truck. If I let off on the fuel it would go away. If I locked out 3rd gear and floored it the sound was not present. I kind of feel like its a torque converter issue, like its not locking up and slipping. Or maybe the carrier bearing? I don't know and the dealer wants me to bring the whole truck, camper and horse trailer in and leave it with them. I really do not want to do that but I may have too.

 

[Joseph Donnelly]

Were you in tow/haul mode? Could the hitch setup be making the noise? What is the combined loaded weight?

 

[NickSullivan]

Were you in tow/haul mode? Could the hitch setup be making the noise? What is the combined loaded weight?

Yes we were in Tow/Haul Mode. I am not sure what the combined weight is yet. I have not had a chance to take it across a scale yet.

 

[Wertles]

Are you sure it's not exhaust drone? While pulling, 3rd gear on up drones quite a bit at 1800-2000 rpm. It revs through first and second too quickly to really notice it (4.10's on mine) but shows up like an angry bear by third gear. You may run into it in second with 3.73's. I was quite surprised to find it on a truck with a stock exhaust as I never noticed it at all on my stock 5.9. Once the MBRP went on it, it was VERY noticeable.

 

[NickSullivan]

Yes, I am positive it's not the exhaust drone. It's very loud, enough to scare my wife.

 

[mpaulson]

On mine when loaded I notice that on the highway when climbing I'll push the throttle a little more then it's like some valve opens under the hood or something and I get a deffinent/sudden change in the tone of the engine, a growl like you are talking about. It's like when I get the peddle down at a certain spot, I can push just a hair more then the sound is there, back off just a little, it's gone, just like a switch at that particular throttle percentage or something, kind of like popping the four barrel carb open when you lay into it. This also happens at anytime, loaded or not when I get the power on aggressively. I'm thinking this is normal from the sounds of this thread??? Of course I'm in tow/haul and about 25,000# total with lots of wind drag.

 

[Deleted member 995608]

There's been some discussion about the drone on forum 'B'

http://www.cumminsforum.com/forum/2013-general-discussion/1091330-cmon-already-really-650-miles.html

 

[NickSullivan]

Right now I believe it was caused from having the air bags inflated to 80 psi thus causing the drive shafts to be at a slight angle. I unloaded the camper today and took my dump trailer out for a load of gravel. They loaded 5.2 tons in the trailer. The air bags were at zero psi. No issues at all. I won't know for sure this is the problem until I head out next weekend with the camper and boat.

I am installing a compressor with wireless remote for the air bags right now. This will give me the opportunity to play with the air while we are driving.

 

[Cummins12V98]

Wow 80psi?

I have 8,780# sitting on my 4 rear tires. I run 30psi just enough to help the ride.

 

[Wertles]

It doesn't happen to feel like running over rumble strips on the side of the road does it? Just pulled my 5th wheel home. Going up a hill at about 25-30, it for a moment felt that way. I lifted, it went away, it didn't happen again the rest of the way home.

 

[NickSullivan]

I think we finally are getting this issue figured out. My passenger side front coil spring was not seated in the coil bucket or the rubber isolator correctly. This cause the spring to be pushed up tight against the frame rail. I'm hoping this is finally the culprit for this resonance/vibration that comes on when we are loaded. This could be loaded with just my empty dump trailer, it didn't have to be a lot of weight. It was very repeatable and would always start around 1900rpm.

 

[Hoefler]

It is exhaust drone, mine has done it since new. Shows up when pulling a heavy load and the engine is doing its thing at a lower RPM. I have played with it enough, that I can replicate it with a light load and the right hill. Look at the exhaust, there is weights welded to the pipe in front of the rear axle, this is to help with the resonance of the torque vibration sent down stream from the engine. Very common with low RPM and high torque engines.

 

[NickSullivan]

Nope, it was the coil spring hitting the frame. That issue is fixed. Now they have to figure out why the new coil spring wants to go right back to where the original did. Its at a frame shop right now.

 

[SnoKing]

I thought is was the weight of the camper hanging off the frame brackets half the time! Maybe that is when the spring pops out of place? Just remember to cross control steering while inverted!

Do you do a wing loaded roll like the 707 did over Lake Washington to keep the horse on their feet?

View attachment 88741

Snoking

 

[NickSullivan]

Take a look at the pictures of the new spring. It wants to go right back to up against the frame rail.

 

[NickSullivan]

Sorry, I don't have any idea why they are sideways this time.

The dealer is out of ideas. Now they are waiting on Ram. Next Monday will be 4 weeks the truck has been in the shop. Its taken me two years just to get them to believe me that there was something wrong with this truck. I am not sure what to do now.

 

[SnoKing]

Is something wrong with the angle of the spring pad that makes in angle off toward the frame rail. Maybe you should have a good frame shop look at it? SNOKING

 

[NickSullivan]

Its been at a frame shop all week. They say it looks good. Granted this is now a Chevy dealership telling my Ram dealership it okay. I asked my dealer yesterday if I could take it to another frame shop and they said they didn't want to do anything without Ram specifically telling them what to do. Part of me thinks its the front axle or trailing arms. Either the pad on the top of the axle is welded in the wrong place, meaning tilted forward. Or, the front axle is pushed forward too far. You would think this would be noticeable from an alignment.

My axles pumpkin is also hitting the track bar bracket mount. So, something is definitely not right.

 

[SnoKing]

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[Hoefler]

In for service Saturday, talking with the service manager, there is a new bulletin out that addresses this to the T. Aisin equiped trucks that experience a drone bewtween 1800-2000 rpm under moderate to heavey acceleration when heavily loaded. Replace the torque convertor. Mine will be here by Wednesday and installed Saturday.