non factory tow, can it be installed?

[KERR]

So im looking at e bay and there is a crew cab 4x4 titan with out a tow hitch. The only real reason im looking at them is to tow with. So if i buy one can i take it to my local nissan dealer and have them install the hitch and be good to go. The wifes armada came with the tow package and does a grate job at pulling. The only problem is when i need to tow i take her ride and becomes not very friendly...

[KERR]

never mind i found the answer in another post

[Aquaholic]

Adding a hitch to a SE is 7500 lbs. Adding a hitch to a LE will tow 7200 lbs. If you find one with the tow package it tows 9500.

[SportCoupe]

OK, the factory tow package consists of the following.

-tow receiver
-lower rear gear ratio
-heavy duty rear springs
-tranny temp gauge
-heavy duty battery

Now, I can see only the rear springs being responsible for the increase from 7500 pounds tow to 9500 pounds tow, nothing else really. Please correct me if I am wrong.

[Yahooligan]

The lower axle ratio as well, the engine has to do less work since the lower ratio increases the torque multiplication. More torque (which is what actually gets you moving) to the wheels for the same amount of work from the engine. Higher gear ratios mean the engine has to work harder to accelerate since the engine will be in each gear longer and until a higher speed.

Think about the difference between starting off from a stop in 2nd gear instead of 1st gear. The difference isn't that great with the axle ratio, but it's the same principle.

Edit: The springs would only change payload capacity, which for towing a 7500lb trailer to a 9500lb trailer would be a difference of ~200lb on the hitch.

[BigA]

Originally Posted by SportCoupe

OK, the factory tow package consists of the following.

-tow receiver
-lower rear gear ratio
-heavy duty rear springs
-tranny temp gauge
-heavy duty battery

Now, I can see only the rear springs being responsible for the increase from 7500 pounds tow to 9500 pounds tow, nothing else really. Please correct me if I am wrong.

I didn't know the springs were any differant, the tow also has the bigger mirrors and wireing for trailer brake controller.

[dank78]

So just your gear ratio makes a difference of 2000lbs of tow capacity? That doesn't seem right.

[Yahooligan]

Originally Posted by dank78

So just your gear ratio makes a difference of 2000lbs of tow capacity? That doesn't seem right.

Why doesn't it? It allows the truck to tow more weight without working much/any harder because of the torque multiplication.

3.82:1 1st gear X 3.35:1 rear-end = 12.797:1 gear reduction w/ BT.
3.82:1 1st gear X 2.94:1 rear-end = 11.231:1 gear reduction w/o BT.

Say you're putting out 300lb-ft of torque at the crank. With BT you're putting down 3839lb-ft at the wheels. Without it you're putting down 3369lb-ft, a difference of 470lb-ft or 14% more torque with BT. More torque to the wheels means you can get a heavier load going with the same effort as a lighter load with a higher gear ratio, with means less stress on the engine and transmission.

[loufish]

So just your gear ratio makes a difference of 2000lbs of tow capacity? That doesn't seem right.

Actually that's about what most trucks see in the difference in rear gears for towing. It's more about the trans, taller gears means more torque the trans handles.