well i just got my truck and i cant seem to know what kind of diff setup i have. of course i don't have an LSD but i don't know if i have 3.55 or 3.91. my truck has stock 20". i used to send my VIN to a member here and he will check and get back to me but it seems he is busy or doesn't check his inbox lol. i would like some help plz. thanx

 

lsd only came with 3.92 so looks like you have 3.55

 

Rez is right, if you know you don't have an LSD, then you've got the 3.55 or the 3.21s. On the sticker it'll say 3.92 as an option. On the 1500s there's also a sticker on the diff on the passenger side that will say the gear ratio.

 

are you saying that if you have the 3.92 you will always have the LSD?

 

Yes, that is my understanding.

 

ill look for that sticker. in my old 2004 i had a sticker in the glove box that stated the gear ratio i have...

 

Correct. The LSD is only in the 3.92 and 4.10 gears. The 3.21 and 3.55 ratios are an open diff. You'll still have ESP on all ratios though, so that's something at least.

 

If you send me the last 8 of your vin number I can find out for ya. I work at a dodge dealership.

 

Look on the front of the passenger side on the rear axle for a sticker with ID info. The gear ratio should be on that. It is on mine (3.92).

Rob

 

X2 - I did not trust the window sticker when buying so I did this on the dealer lot !! A year later and I can still wipe off the axle sticker under there and see the ratio.