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I can't pull this trailer

14K views 29 replies 22 participants last post by  RnEmOvr 
#1 ·
I don't know what's going on, Cummins are built to pull. This past weekend I loaded my Chevy on my dad's 35' gooseneck and brought it home, 15 miles. My last truck, (2006 Mega Cab 3500 SRW, G56, 3.73, 37s), screamed in 5th trying to hold 65 mph. Before anyone blames it on the 37s, my current set up is 2006 Reg Cab 3500 DRW, G56, 3.73, 33s, and it had the same problem. Intake, exhaust, programmer were all the same on both trucks.

*This is my 4th 2006 Cummins, all have pulled this trailer the same*

Old truck, (didn't haul both, just wanted to see if they fit).



New truck. The Chevy was about a foot too far back, but it was fine.





-AFE stage 2 intake with S&B filter and filter and pre-filter
-4" straight exhaust, no cat, not muffler
-Bully Dog Triple Dog

This past weekend it was pretty windy and I was driving straight in to it. I also know that my chevy is like pulling a giant shoe box down the highway. 5th gear, pushing as hard as I could, trying not to smoke my clutch, I was holding at 1200*. Each tire and wheel on the Chevy weigh around 250 lbs, and the rockwells weigh 1100-1200 lbs each. The rest of the truck is just a small block Chevy 1/2 ton 4x4, not that heavy.

I don't think the trailer is at fault? I've hauled the Chevy and a Jeep TJ on this trailer with my dad's Duramax, and it pulls it easy. It's not just his truck, he gets a new demo every 5,000 miles and I have pulled this with 6 of his trucks. I have also pulled the same set up on our shop truck, 2006 Reg cab 3500 DRW Duramax and it pulls it easy.





I would think that my black dually would tug this around all day long without breaking a sweat? Even unloaded, this trailer is a challenge to pull. I know it's a big heavy trailer, but should it be this hard?
 
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#2 ·
Dumb suggestion but I would assume that the plug is a six round, so I would check how the wires are hooked up for the brakes. I know i have hooked up to some trailers and the brake wire would be in the center instead of the side, and my brother rented a truck one time and it had 2 in the bed one was labeled old and the other new and those adapter things from 7 to 6 are all wired with the brake in the center. I have a 02n 2500 and I've pulled a 40ft, unloaded but able to pull it fine, and i see 3500 dully pulling them every day hot shoting. Like I said dumb suggestion but worth checking
 
#5 ·
That's a good idea, and the first thing I checked. It's a 7 pin, both my bumper plug and bed are wired the same as the pigtail.

Something is definitely wrong (with either the truck or trailer) if it's difficult to pull UNLOADED....
It's not "difficult," just heavier than I think it should feel. I'm not really complaining about it unloaded, I just threw that in there. I know it's a big trailer, and I'm going to know its back there. Comparing an automatic Duramax to a standard Cummins is apples to oranges, but it blows me away how my Dodge's have struggled hard and the duramax's cruise right along without a problem at all. It is tiring pulling this load with my dodge, and with my dad's truck, I have pulled 6 hrs up and down hills comfortably, never having to plan an ascent up a hill.

I've pulled trailers, (mainly with Chevy's), since I first started driving around in the pasture. The two 24 valves I've had got the job done, but I didn't pull anything this heavy with them. I see hay haulers with similar trailers, loaded down with round bales that have to be heavier than what I'm pulling.

I guess I need to have one of my friends that hauls heavy with his cummins drive mine and see what he thinks.
 
#3 ·
I was thnking the same thing about the plugs. Actually rewired a trailer wired for an older chevy to work with my dodge.
 
#13 ·
Where I work, they swap a couple of wires under the trailer. That way if someone steals the trailer and plugs in the trailer, it will put the brakes full on all the time. Maybe they did that with the trailer??? Just because the wires match in the plug, does not mean they are connected that way on the trailer.
 
#6 ·
What gear ratio did these Chevys have? And what tire size? It seems that your truck is not set up properly for heavy towing. Also, 1200 is not too high for egt and id suggest switching to a Smarty or EFI Live.
 
#7 ·
The Chevy's have 3.73 gears (same as mine), and 285/e BFG A/T that measure out to 32.5" (0.5" shorter than mine). I guess it's time to try out a Smarty, can't hurt. I've been meaning to get one, but I always end up buying something else truck related at the time.

I have not tried towing this load with stock tires. And my Chevy might weigh more than I think it does. I'll try it out with stock tires and take it to the nearest scales and see what's really going on back there.

I just can't believe the drastic difference between the two types of trucks. I am interested to know why; that is why I started this thread. I will get as much info as I can to help diagnose even further.
 
#8 ·
It'd be easy enough to pull the trailer plug and take it for a small test run. Just be careful of the location since you'll have no brakes or brake lights. I'd find a back road and try it that way.

Mike
 
#9 ·
G56 with 3;73's is perfect for towing. I was dragging a 40 ft 8k flatbed around all the time and have had up to 21k on it and had no issues. sounds like something mite be hanging up in the drums on the trailer. I also think you carrying that truck to far back on the trailer.
 
#10 ·
I have a buddy with a 94 12v with 4.10s that will act about the same as my 07 g56 with 3.73s with a decent load behind it.
 
#12 ·
I'm betting, with the tires listed, that the speedo is at least 10mph off - if it's not been recalibrated for the larger circumference tires. .02
 
#21 · (Edited)
The speedo has been recalibrated for the tires.

I have pulled a lot of trailers in my short life and if the brakes were wired wrong, you knew it as soon as you started to drive away. The tires would slide . . . That being said I would adjust the brake pads on the backside of each backing plate as maybe they are too tight, BUT even with that the rims would be so hot to the touch after a few minutes at highway speed that I think you would have blown tires or had bearings go out by now.

My wife has a Chevy and it cruises down the highway no problem with any load, my dodge does turn a lower RPM and pulls the same loads with better MPGs but it sounds louder in the cab than the Chevy.
:agree2: looks like the brakes would either be on or off. Not half on...so to speak.
I thought about brakes dragging, but I've never had a trailer just drag the brakes. They were either on or off. I'll hook it up and check them.

I gross out at 30k and my truck pulls that load better at 75 than 65 because of my rpm range. I am around 0 sea level 50 300' so egts are not an issue unless I lug it in the 1800 range. The engines like 2100 rpms and above when really working. That truck and trailer combo is not all that heavy and you should not have a problem. There is an art to winding out the gears and I assume you know how to. Automatics makes pulling heavy trailers seem much easier.
Yeah, I know how to wrap out the gears when towing or at least I think I do. I normally shift around 2700-2800. Pulling our 6.2 cu yd dump trailer isn't that bad at all. That brings up another question. All of our other trailers work fine on both makes of trucks. I'm going to mess around with it this weekend. Brakes, wiring on the trailer, wiring on my truck, with and without the trailer plugged in, without my programmer, my brake controller, and I'll even try to get some videos.

Thanks for everyone's help. I know it's not easy diagnosing a problem on the internet, but I really do appreciate it!
 
#15 ·
I was wondering what truck you were driving this month, Ross. lol

I'd try what mikebol said, take it out somewhere, unplug the trailer and see what its like. our 20ft gooseneck did that to me a while back when I got the truck im in now....turns out my plug was wired differently and was dragging the brakes.

-Zach
 
#16 ·
You should have know problem towing that setup, it cant possibly weigh that much. As stated before maybe your brakes are dragging. I pull 18k up and down I35 all day long and I dont even feel it behind me. Im not far from San Marcos if you want to hook it up to my truck and see if there is any difference?
 
#18 ·
I have pulled a lot of trailers in my short life and if the brakes were wired wrong, you knew it as soon as you started to drive away. The tires would slide . . . That being said I would adjust the brake pads on the backside of each backing plate as maybe they are too tight, BUT even with that the rims would be so hot to the touch after a few minutes at highway speed that I think you would have blown tires or had bearings go out by now.

My wife has a Chevy and it cruises down the highway no problem with any load, my dodge does turn a lower RPM and pulls the same loads with better MPGs but it sounds louder in the cab than the Chevy.
 
#20 ·
I gross out at 30k and my truck pulls that load better at 75 than 65 because of my rpm range. I am around 0 sea level 50 300' so egts are not an issue unless I lug it in the 1800 range. The engines like 2100 rpms and above when really working. That truck and trailer combo is not all that heavy and you should not have a problem. There is an art to winding out the gears and I assume you know how to. Automatics makes pulling heavy trailers seem much easier.
 
#22 ·
Just a note, this truck has an Impulse trailer brake controller in it. I've always used Draw-Tite. I'll be sure everything is in working order and not sending any light brake signals.
 
#24 ·
I'm lost as to why you need to jack up the trailer???

Has anybody tried to drive anywhere with the hot wire and brake wire switched? You DON'T go anywhere . . . Same thing as jacking the little slide on your controller all the way to max and attempting to drive, it ain't going to work.

If Mr. Chariot has towed for hundreds of miles like this then it isn't a brake issue as he either a) would have burned the crap out of the pads, magnets, etc if they were adjusted too tight or reversed as some people think b) the brakes don't work and he doesn't use them when he stops. I don't thing either of them are right so its a truck problem IF there really is a problem. I have a Dodge in the garage and a Chevy sitting out front, trust me, the Chevy just runs and you don't notice if it even struggles at all, and it has 4" exhaust with a small muffler but its not loud at all. The cummins is loud inside, especially when climbing a hill. It runs lower RPMs but the noise is louder maybe making you feel like its working harder.

Main thing I would look at, is what are the EGTs, boost, RPMs, and gear at a few different speeds with the load you are talking about. Get those numbers and I can throw you some numbers back to compare with (your a stick right?)

Last thing I will say is hauling a flatbed with weird oddball crap stacked on it (aka mud truck or in my case a bunch of flatbeds stacked on top) suck aerodynamically. There were a few times I had running across the Mojave desert where I was in 4th just maintaining 4th gear fighting the stupid headwinds. Once I dropped out of Tehachapi into Bakersfield I could drop into 6th and cruise at my normal 65.

Report back :thumbsup:
 
#25 ·
Last thing is having the Jeep in front of the mud truck helps a lot aerodynamically. And why are you worried about smoking the clutch? Is it slipping?
 
#26 ·
I appreciate it, I'll get numbers at different speeds, against and with the wind. My clutch isn't that bad, I can slip it in 5th unloaded if I floor it just after shifting from 4th. Valair and Smarty are next on the list to call. I would not be surprised at all if it has to do with aerodynamics now that you mention it like that, it does make sense.
 
#27 ·
You don't mention the age of your trailer, but I would be looking for a rubbed wire that may be letting some current bleed over into the brake signal. I searched for weeks to find a running light wire with a bare spot; just enough voltage bleeding through to drag the brakes (and only after dark when the lights were on). Then again, if the D-max pulls it fine, it may be as simple as a dirty connector on the truck. Perhaps not likely across several Dodges, but I would check the easy (cheap) stuff before I started spending $$.
I see nothing wrong with taking the unloaded trailer to an empty backroad and unplugging from the truck for a short tow. This will verify beyond any doubt if the problem is electrical related. May not fix anything, but it could at least eliminate any questions in that area.
Good luck, I know how frustrating these problems can be when troubleshooting takes you in several very different directions at once. Process of elimination is the only way to get to the bottom of it.
 
#28 ·
i agree with this.


I would find an empty strech of road, and brig it up to speed empty and see.

IMO there is no way your dully won't be able to stop that trailer empty. something ain't right, that trailer can't be more then 5-8K empty.


, my 99 hauls heavier, so does the 08. without trailer brakes i have been abke to stop it, so there is something wrong here.
 
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