Hi guys,

I recently bought a 2004 Quad Cab Laramie 4WD and want to tow a 7500 travel trailer with it. I've been researching and so far here is a summary of what I've found:

- Engine is the 5.7L Hemi with automatic transmission
- My axle ratio is 3.92
- I don't believe I have the tow package, the electrical wiring coming out of the rear bumper is only the 4 pin
- I believe I have the limited slip differential (inside the glove compartment, there is a specs label that lists the axle ratio 3.92 and limited slip differential but nothing about a tow package)
- The towing guide on dodge.com lists four possible weights of 7550, 8550, 8600 for my specs (not sure why the different values). Here is a link to that:

http://www.dodge.com/towing/D/vehicl...c+Transmission

- I have a hitch that lists 5000lbs as "carry load" and 12000lbs as "distributed load." I believe this must a be class III? Do I need a class IV to tow a 7500lbs trailer? Or should I install this "distributed loading" system on my trailer?

- I already emailed dodge for a build sheet, but then I believe what I found in the glove box was it, so I probably don't need that anymore.

What is the best approach to get the truck in a shape that can do the job? Should I be installing a tow package? What exactly is in a tow package anyways? I know I need the 7-pin electrical socket (instead of the 4-pin that I have) because the trailer has its own brakes.

I've already got a hitch, do I need a better hitch? Or can I go this "distributed loading" way?

Thanks,
Kaveh

 

Without the trailer tow package you probably do not have an auxiliary transmission cooler. I would make that a priority if I was going to tow that kind of weight.

A good weight distributing hitch will set you back about $200, get one. You'll control that heavy of a load much better with it.

7 pin for sure and you may even need a brake controller. The other thing I'd strongly consider is a set of air bags for the rear of the truck as I'm sure the tongue weight of a 7000# load is going to be rather high.

Depending on terrain, you'll probably see single digit fuel economy towing three and a half tons, not much you can do about that short of buying a diesel truck...

 

Factory tow package for my 05' was only the bigger battery, tow harness, 136 amp alternator, and class 3 hitch. The transmission lines do NOT go into the radiator, but rather into an external oil cooler. There was no change to a bigger cooler with the tow package option. I added an aftermarket cooler and fan to the existing factory cooler as I live in AZ, and I want my transmission to live. The best way to make it live is to not abuse it, change the fluids religiously, and keep the fluid cool.

Change you rear diff fluid as scheduled (every 30K miles or less), and use the best synthetic lube you can find with and add the friction modifier from Mopar. PN 4318060. Some lube already comes with friction modifier included, so read the bottles. Mobil 1 Synthetic Gear Lube 75W-140 is arguably the best, and has the friction modifier already in it. The 3.93 LSD rear is a nice piece, except for the dreaded clutch pack retainer failures that can take out the whole rear end. This is probably why Dodge recommends changing fluid every 30K, so the catastrophic failure might be avoided if there are metal fragments banging around the rear end. Lots of guys upgrade to an aftermarket LSD to avoid the worry about the clips. 04's seem to have a higher occurrence of failure that later years.... The clips were thinner for that year.

I'd recommend spending the extra money on an OEM (MOPAR) towing harness, rather than an aftermarket. You should be able to find one for as low as $70 + shipping. Part number 82207253AB. http://www.mopar-accessories.com/en-...=3060&pc=45981

The Tekonsha Prodogy or P3 brake controllers are very good. http://www.etrailer.com/Brake-Contro...sha/90185.html

You will also need a brake controller adapter cable to plug into the blue brake controller port that is on the left hand side of the firewall, under the dash board. http://www.etrailer.com/Brake-Contro...ha/3020-P.html

 

That's weird, according to Dodge's specs for 2005 (2004 as well), the only factory tow group listed is Class IV which includes:

AHC - Trailer Tow Group
BAZS - 136 Amp Alternator
BCQP - 750 Amp Maintenance Free Battery
DMH - 3.92 Axle Ratio
GPG - Power Trailer Tow Mirrors, Fold-Away
NHBP - Auxiliary Transmission Oil Cooler
NMCP - Heavy Duty Engine Cooling
XFHP - Class IV Receiver Hitch
XFKP - 7 Pin Wiring Harness
XFUS - Trailer Tow w/4-Pin Connector Wiring

All of these items also appear on the right hand (options) column of my window sticker. (yeah, I'm a hoarder, I keep the sticker in my glove box with the manual, LOL).

I can't even find where a Class III is even offered as part of a package. I can find a Class III hitch individually, but not as part of any tow group.


An excellent point and one I completely let slip by. Actually the clips were not changed until mid year in the '05 builds, most of the '05s have the thinner clips but about the last 25% of them had the slightly larger clips installed. I still see failures with even the newer clips, but not at the rate of the earlier ones.

Although I dunno if I agree with you that the 3.92 LSD is nice. The 3.92 gearing is sure a good bit better than having 3.55s for about any situation, but even the clip issue aside, the LSD isn't really on par with either Ford's or GM's offerings (I think the Z71 package LSD is on par with most of the better after-market ones myself). The Ram LSD often needs to be "prodded" into engaging by depressing the brake slightly or applying a touch of e-brake. Also, I think that any LSD with a bias of less than 2:1 isn't a very big advantage over an open diff, at least for my uses.

 

Thanks guys,

Question about the rear airbags, it seems to me that the function is to make the rear suspension much harder to keep it level under the tongue weight of the trailer? but then what happens when there is no trailer or payload? Does it impact the unloaded riding comfort? Do I take them off every time?

 

I don't have a factory towing package but my '04 has a factory transmission cooler in front of the radiator. Not sure if it's the same size as the one you'd get with the factory tow group or not though.

 

Personally, I wouldn't tow a trailer with that kind weight. Assuming you fit the truck with everything the tow package has, your truck will be rated at 8600lbs. Typically you shouldn't go over 80% of the max towing which in this case is 6880lbs. I am assuming that the 7500lbs is the dry weight. If that is the case, you have to add whatever cargo you have in there, plus passengers. She'll work pretty hard to pull that. Just my two bits.

 

I understand, but 7500lbs is my GTW, the dry weight is 5100lbs, so I think I'm safe as long as I don fill it to the max, but I'd like to be prepared for the worst.

 

Yes, they keep the truck level and more stable when hauling or towing a heavy load.

That is the beauty of air bags as opposed to add-a-leafs, you can easily adjust the amount of air in them. At minimum PSI you'd never know they were back there. Plus, they are very inexpensive and can be installed in the driveway with basic tools in about two hours.

I have a set with a max of 100 psi of air and have had 2200 lbs of river rock in the bed (way over capacity) and with only 40 psi of air my truck sat dead level.

 

Ah...I thought the dry weight was 7500. In that case you should be ok. My truck has the trailer tow package, and my trailer has a dry weight of 5077 lbs, and it pulls it no probs. Two big biggest things to consider is the tranny cooler and rear airbags. Sorry for the confusion!!