I have a 2007 1500 Quad Cab with the 5.7L engine. I recently purchased a travel trailer that weighs about 6000 lbs dry, 7000 loaded. Although my truck is rated to pull this without issues I noticed the rpms seem to fluctuate too much. Trying to drive around 2000 to 2500 rpms only works if I stay around 60 miles an hour. To drive 70 my rpms stays at 3000.

1. If I drive for several hours pulling a trailer with my rpms at 3000 is that too high?
2. How can I increase my low end torque to reduce my rpms?

 

GEARS, 4.56s... Believe it or not, even though that gearing increases RPMs at a rated speed, the tranny will not search for the right gear like it does now (that's what's causing your rpm fluctuation) and will settle into a higher gear for longer periods when pulling.

The only real way to increase low end torque significantly enough to notice would be to cam it with a cam ground specifically for this and going to a custom tune...

 

Welcome to DF.

First, before anything else, please read this:
https://dodgeforum.com/forum/dodge-ra...s-section.html

I will move this to the 3rd gen section for ya.

 

LT headers may help a pinch, but the shorter gears will certainly wake it up.

 

+1... but, for what it's worth:

shorter gears would be higher gears, and numerically lower.. taller gears are lower gears, and numerically higher.. think of them like cogs on a bike's rear wheel.. the larger the diameter, the lower the gear, the 'taller' they are.. on a 21 speed, or 28 speed bike, the front chain rings operate akin to your transmission output, and the rear cogs act like axle ratio..

the taller, the more times the output shaft has to rotate to rotate the gear once..

 

Can you tell me what I should look at for installing a new cam and gears? Brands, etc...Also, do you have any idea of the cost of each of these? I really hope I can find something to help with this problem as I don't want to buy another truck. This is my first dodge and I really am enjoying it.

Thanks for all the input.

 

You torque cams can vary depending on how wild you want to get. you could go with a Sidewinder form FRI and run off SC tune. If you want to go more aggressive and custom tune with SCT or Diablo you could go more aggressive with something like a crazy spartan, crazy jay, or crazy frog, from inertia. Other options would also include the KRC 210 and 210X which I believe are even a little more aggressive yet, and would require custom tuning. Weed could chime in and verify some of this info, as i am just repeating what I have read/heard, second hand.

Theses prices are based on all new parts, and could be found for cheaper if your keep your eyes open of forums etc. Price wise your looking at

Puts you at ~$1,000 - $1300, without labor.

If you go to a shop they will kill you on labor, if you know some one that could do the work or have a connection somewhere it would obviously be cheaper. Of course you could always do the work your self if you are up to the task.


Gears-
don't know if your 4X2 or 4X4 but the gears and master install kits (for motive gears) run about $280 (2wd) to $600 (4wd). labor to install can vary quite a bit from ~$200-600 per axle depending on the shop. Keep in mind these AAM diffs are not for everyone. there are not too many shops that set them up properly, so you need to thoroughly check them out before having the work done.


nateroach

 

What size tires do you have on the truck? Also, trailer tires are only rated for 65 MPH. I have a 4.1 gears that I can usually maintain in 4th gear so long as there is little head wind but I keep the speed to no more than 65 MPH towing. If you went to the 4.56 gears then you would be around 2625 RPM at 70 MPH. How much do you tow with the truck? There is nothing harmful about going 3000RPM all day long except for maybe noise. In the past we ran around 3000RPM at 70MPH with 3 speed transmissions.

 

Update-I just pulled my trailer for 200 miles and with overdrive disabled I can easily stay at 70 running at 3000 rpm. I get 7.5 miles to the gallon, this was with a headwind in hilly terrain. When I got to a flatter condition I can almost pull the trailer in 4th with my rpms closer to 2300, but sometimes it struggles to maintain speed and needs to downshift. If I could pull in 4th my mpg would be much better. Does it still sound like I need a cam or gears, or just more horsepower? I am running stock 20inch tires

 

Well, the 20s hurt for sure, your towing capacity is even 1000# lower with 20s as opposed to 17s. But if you are gonna tow on any kind of a regular basis, I'd seriously consider 4.56 gears.

I would just about bet the ranch you have 3.73 gears which IMO shouldn't even be offered in a 2500 or Mega gasser. They should just use the optional 4.10s standard and leave the 3.73 as entry level for the diesels which have the low end torque to make up for the gearing.

HP is not your problem, Furds with the 5.4 Triton pull better than Rams with the Hemi despite having a solid 100 HP disadvantage...