I have an 04 1500 Ram 4x4 5.7 hemi quad with swb. The gears are 3.53. I bought this without knowing anything about towing and at the time only intended on towing a pop-up trailer which we never felt behind us. We upgraded to a 25 foot camper approx 5,000.lbs. When in the hilly areas we noticed that we really have to work to get up some of the hills. We have only modified the truck with a K&N air intake kit so far. What should we do to give this truck a higher towing capacity? I have heard changing the rear gears would help? How much would something like this cost? Would my fuel mileage suffer? I have 12,000 miles on the truck now and would get screwed over by trading it for a 2500 ram. Thanks Howard
Changing rear gears is certainly the best bang for the buck. 3.92 should be fine, but if you live where speeds are rarely >65mph'ish, you might even consider 4.11. As to cost, that can vary. To simply change the gears, you're probably talking about $200-300 per axle. The front axle is usually a little more, because it's tougher to get to. If you don't already have LSD, you might consider that. Dodge trucks with the corporate 9.5" rear are pretty famous for lunching the carrier bearings at 60-80K miles. If you take it to a shop for a gear change, have them put some quality bearings in there. Then you never have to worry about it.
Lower gears give you more "grunt" and will get the load moving faster... they will also make the truck run at higher RPM, so your hiway mileage will decrease... Some folks say that lower gears raise the MPG in town, because the truck doesn't have to work as hard to get moving???
IMHO, the K&N is doing what it does best, making noise, and what it does even better, letting more dirt into the engine.. other than that, it's worthless..
On the other hand, I have to wonder if you're towing up grades in OD?? We have a 99 ram quad cab, 2wd, auto, 5.9 gas, 3.55 rear end... we haul a travel that's 5,000# dry, probably close to 6,500# loaded with all our crap, and it takes a major grade to slow us down a lot... you have more horsepower and more torque with the hemi, so you should out tow us by a big margin.. Does your Ram have tow-haul mode? Are you using it?
A General rule of thumb is that if the truck is "hunting", or up and down shifting a lot, you should have OD locked out... We always tow without OD, figuring that you can't hurt it to lock out OD, and our MPG is the same or better with it locked out... YMMV
You'd to want to change the front as well. Why make a 2wd out of a 4wd. Changing to 3:90 or 4:10's will cut into you fuel economy. Throw out the K$N and put the stock filter back, that way you can hear your wife while she's telling you that you bought the wrong truck. What do you mean by "race up"? You might want to see just how bad things would go if you were to trade up to a 2500 with the Cummins. You are going to be tossing a grand anyway at this one and then you probably won't be totally happy with it. Right now there are some decent deals around.
this statement is probably the best bet in my opinion if you look at most owners manuals it will say something to the effect that if you tow or haul anything over a certain weight (practically any trailer or anything with any size in the back) that they recomend you use tow/haul or o/d off. now as far as your truck having the power to pull 5,000 lbs?? id think you would be fine. a good 1/2 ton should be able to handle a camper of that size no problems.
The front and rear gear ratios need to match. Otherwise, when in 4x4, one set of wheels will try to turn faster than other. Does strange things to the handling.
Depends on the type of driving you do. If most of your driving is 65 mph or less, it may actually improve it by keeping the engine closer to it's power peak. I would expect your towing mileage to improve or stay the same, because you won't need as much throttle opening to do the same job. OTOH, if you live in Montana, and routinely cruise along at 85 mph, changing gears will probably decrease mileage.
Depends. Many times the rpm's climb dramatically because you've downshifted in to 2nd to make the hills. With better gearing, you'll only be down in to 3rd.
Over the years, a lot of testing has been done on Dodge engine to see what makes more power, and what doesn't. A good open element air cleaner was one of the few items that did (although not very much). I wouldn't get rid of it, but I would figure out a way to shroud it to prevent the noise intrusion into the cab. I have one on my truck, and although I can hear it, it certainly isn't intrusive. Are you sure the noise is from the air cleaner? Try putting the stock parts back on and run the same route.
That's OK. We all gotta learn some time.
For reference, here's a little chart to compare speed and rpm's in different gear ratios:
I've got an 04 Durango Hemi also, 2WD, 5 speed auto. With the tow/haul engaged should it be shifting into fifth gear? The manual says it will stay out of overdrive but is OD different than fifth? I tried using the cruise control while towing, at seventy mph it wouldn't stay in any gear longer than a few seconds (kept shifting up/down). I'm probably towing close to 6000 lbs., mostly tow on level terrain to slightly rolling. I'd like to be able to control the shift points, maybe keep it out of fifth altogether. Thanks, B A R
LSD stands for limited slip differential, sorta like GM's posi rear. While helpful for traction on dry and somewhat slippy roads, it can cause fishtailing on wet roads in turns until you get used to it.
Without question. Your 4WD is not going to work very well if both axles are always trying to turn the wheels at different speeds.
In the city, it may actually improve but on the highway without towing, it is going to drop. The amount really depends on how fast you like to drive.
No, because it will always be running faster and have more torque due to the lower gearing.
The easy answer to that is to lose the K&N. You will find that it really isn't doing all that much for you.
When in tow/haul mode it locks out 5th gear. I believe 4th is still OD and 3rd is 1:1. On flat terrain mine will sometimes shift to 4th but often stays in 3rd. It does not shift back and forth. 4th can pull my trailer at 65mph. Any slower and it's bogged down and struggles. It really needs to stay in 3rd when towing unless very flat and over 60mph. Up steep hills it will shift back and forth between 3rd and 2nd so I manually shift to 2nd on the steep grades.
There have been some transmission programming changes so you might check with your dealer as to what you already have.
A lot of what you're feeling, ("I just seem to really have to put my foot in it to get up the roads in our White Mts.") is quite normal for towing.. you just get used to it.. When we were towing a little tent trailer, we'd zoom up grades... but when we switched to a 6,000 pound (loaded) trailer, we pretty much doubled the weight of the truck and added 4 wheels... you're not going to pull hills the same towing as you do not towing, unless you have 2 or 3 times the power that the truck need to move itself..
We went to the coast for the weekend, and that involves pulling 3 or 4 small (1,500 foot or so) hills... one is a 3 mile, 7% grade... we did about 40 mph up it at about 3,500 rpm... no big thing, we made a lot of noise going slow for a few miles, the engine and tranny temp stayed ok, and we went down the other side at the legal limit.. My guess is that if we had a K&N (or just NO filter) we would sound like we were doing about 6,000 rpm.. lol
The thing that helped us the most wasn't mechanical, it was mental: We had to get into the mind set that this was a Recreational Ve chicle, so we should relax and enjoy the trip... if we're in a hurry, we leave the trailer home and stay in motels.. YMMV
Even a 3.92 is not likely to be enough for you needs (nor a 4.10) You have a few problems here. The biggest one is the engine itself which is GREATLY over rated for truck duty. The HP ratings look inpressive on paper but most towing and trucking is done below 3500 RPM where the Hemi is kinda gutless and no intake filte change or exhaust change is going to fix this. Chysler should have modified the cam timing and ports for less peak HP above 4000 RPM and more usable HP and torque at lower RPM?s where you need it in a truck. It also lacks displacement which mean torque too. (even the old 360 has more grunt below 3500 RPM in the seat of the pants than the Hemi does) How do you fix this? GEARS!!! Get the engine RPM up under load so that it can make more power because nothing you can do short of super charging is going to make it deliver more low torque at lower RPM?s so forget trying that. When you consider gear ratio you must factor tires size and the loads you plan to haul. A 4.10 would be bare minimum here with a 4.56 a better choice if you have some serious towing to do. These ratios are not as high as they sound with 32 inch tires and OD and I doubt the mileage will change much with a 4.56 because the engine will be cruising at a more efficent RPM and with a 4.10 it might even improve a bit when not towing and the 4.56 should improve towing MPG a noticable amount. A engine uses the less amout of fuel per HP hour producted when it is operating near it torque peak (which is also were peek VE occurs) and seen the Hemis is at about 4000 RPM you never realy get there ever in daily driving and going through gear getting moving with a 3.54. With a 4.56 you should be able to tow 8 to 10,000 lbs without too much fuss, even in hilly terrain and still cruise nicely in OD.
These "rated" towing ratings are not based on any real science because some of them are overly generous. THey do not factor in wind drag (because a 8k low profile load on a flat bed will tow easier that a 6k high profile travel trailer) and whether ground is hilly or flat is a factor too Also if a vehicial can tow 5k well, 6k will not break the bank. Personally I do not care what any factory tow guide says because a hemi in a big SUV with 32 inch tires and a 3.54 axle ratio will have a tuff time with a 5k travel trailer especaily if there is hills. Tires have gotten bigger and trucks heavier but axle ratios have generally stayed the same. To me a good tow vehical for the weight being towed can tow the load up just about any hill on you will see on the interstate without downshifting below drive and not have to be floorboarded either. If you are reaching for the floor and/or second gear a lot you have exceeded your capacity. WHen you gear axle lower/deeper it does two things, it increases the amount of wheel torque put down to ground in any selected gear and it allows the engine to crank up a little more and to be closer to its torque peak when climbing a hill in drive at speed which gives you maximum pulling power.
A very general and unfounded statement. new 1/2 tons are usually geared to squeak that last 1/4 mpg out on the rigged EPA MPG dyno test. I half ton truck with 31 ot 32?s tire on a heavy extended or crew cab with 3.42 (GM) or 3.54 (Ford/Chysler) makes a poor towing platform for a 5000lb travel trailer. I recently drove a new chevy Z71 extendend cab with a 310hp rated aluminum V8 and 3.42 gears. It was very strong above 3000RPM if you wound it out in 1st and second but it was lacking in drive and a flat out snail in 4th/OD. I shudder to think how poorly it would tow a 5k travel trailer than it is rated to tow. A Hemi in a CC dodge truck with 3.54 gears would be about the same or maybe just a tiny bit better. I do not care if it is rated at
345hp or so above 5000RPM as you do not tow at 5000 RPM and it is seriously lacking below 3000 RPM too. Dodge has really screwed some truck owners with that combo. It would be more managible if they would increase the Hemi?s displacement in the truck by 30 or 40 cubic inches but I do not see that happening. It is like they are forcing your hand into a profitable (for them) $6 or7k option Cummins if you want to tow anything of any real weight while you add an extra 600 lbs to front end of truck too. They could offer more axle ratio option for the gas engine but then that might take away Cummins sales. There is a crew cab 1 ton dualie at a dealr near her with a Hemi in it and it has been sitting there for about 8 months now. We drove it for grins when my freind was looking at Cummins power trucks and it was a bit of a slug and would be a joke with a big trailer on it too. When Dodge replaced the V10 with the Hemi in a truck they really screwd up because the V10 might have used a bit more gas but it would pull very strongly too, much better than the higher HP rated hemi that replaced it.
Guess you have never lived there, I have and the faster you go the more power it takes though some think otherwise. Drag is not constant and it climbs A LOT after 70 MPH or so AND most of Montana is about
4000 to 6000 feet above sea level (except for eastern plain and the high line) and your engine loses power as you go up in altitude (approx 3% per 1000 ft) and no tweaking will make up for the loss either. Also the higher you go and the thinner the air the more you need gears to haul the load especailly on hills. You REALLY feel it above 8000 feet or so when you suddenly realize that you have been floor boarded on a long hard climb but did not know it because the engine does not sound floorboarded because it is down on power so much. At time like this you want all the gears you can get sometimes and OD would be totally useless above 5000 feet or so in a 4x4 unless you are geared pretty deep to begin with. In the old day (from about the 50?s through mid 70?s or so) trucks that used to ship to higher elevations from factory came with deeper gears to offset power loss but as emmission and MPG rating tightened they phased it out to ease certification.
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