I was reading the trailer life towing guide and it says for the RAM 1500 I can have a max towing capacity of 7800lbs with
either

A) Requires 3.9:1 axle ratio.

OR

D) Requires 3.5/3.9:1 axle ratio.

I don't get it. Which is it? I understand the 3.9:1 axle ratio but what in the world does "3.5/3.9:1" mean? Seriously confused here.

 

sounds like a typo to me.

I know the rear end of the 1500 has the 3.54(I think) or the 3.92. the 3.92 will give slightly more towing ability since you are putting the engine at a higher RPM.

 

Don't think it's a typo because each edition of the towing guide shows the same thing.

 

you know. . .they could be saying 3.5:1 and 3.9:1 and just shortening it by one charachter by putting it like that 3.5/3.9:1, that is realy the best thing I can come up with

 

They're probably footnotes, meaning that if there is an A in the column then it requires the 3.92 Rear End. If there is a D then it requires either the 3.55 or 3.92 Rear End. If you could somehow scan an image of the page and post it up then that would help tremendously, but until then I'm just guessing, and that is my best guess.

 

This is the way it reads

Ram 1500 4WD 5.2 V-8 4,800 d,g,k
Ram 1500 4WD 5.2 V-8 5,300 a,g,k
Ram 1500 4WD 5.2 V-8 7,800 a/d,b,k (THIS IS WHAT I AM CONFUSED ABOUT!)

a Requires 3.9:1 axle ratio.
b Requires four-speed automatic overdrive transmission.
c Requires three-speed automatic transmission.
d Requires 3.5/3.9:1 axle ratio.
e Requires 4.09/4.10:1 axle ratio.
f Requires either a 3.5/3.9/4.09/4.10:1 axle ratio.
g With five-speed manual transmission.
h Towing not recommended with 3.21:1 axle ratio.
i California gcwr may differ.
j Requires towing package.
k Club Cab rating slightly lower.
l Requires 3.21:1 axle ratio.
m Requires manual 5/6-spd transmission.
n 4WD not listed by factory at presstime.

 

It's for the automatic, if you read footnote g, then footnote b, you'll see that they describe the transmission, so with the auto it doesn't matter what rear end you have, you're going to be able to tow 7,800 lbs.

 

This is easy as pie:

They put that into the wording in because they are both towing rear ends. Although, if you have a 3.9:1 you have more towing capability. If you have the 3.5:1 you have a substanial loss in towing about 2000 lbs.

Auto trans comes with a 4 speed usually.
Manual trans comes with a 5 speed usually.

Then they hook the trans up to rear end. Depending how much torque and HP at the wheels with added stress without over working the motor and drive componance is where they put their ratings. So first things first, you have 4 different setups, the buyer desides which combination he will choose. More power or less. More fuel econimy or less. And finally What he prefers. They are just tring to break down which set up you got. But to me your main problem is a typo.

 

The reason is because they came out with the optional Auto 5-spd transmission, which makes the towing capacity the same.. Meaning if, (like my truck) you have the 3.55 rear, and the 5spd auto tranny, you have the same towing capacity as a truck with a 3.90 rear and the 4spd auto... Gas mileage will change dramatically as well..

 

The 318 was never mated to the 5-spd. Only the Hemi and 287 were ever mated to the 5-spd.