Hi, I have owned my 07 quad cab hemi since new.

The window sticker says that it has both. Under the "customer Preferred Package 26G" it says 3.92

Lower on the sticker, under the "multi speed auto transmission" it says 3.55 axle ratio.

The truck has the factory tow package, and was a "Thunderroad" 4x2.

 

I believe 2WD's typically have 3.55's. Just because it says tow package on a sheet doesn't really mean anything too special. I mean why wouldn't a truck have a tow package? lol. But it could be a option so it's possible you have 3.92's. I believe your glovebox has a sticker (unless thats the one you were talking about) and I think you can also check about the differential for a tag or something. I can't give specifics because I haven't done this myself haha.

 

You probably have the 3.92s, the 4x2 with auto typically comes with the 3.55s but the 26G pkg probably gave you the 3.92s.

 

if it lists it on the sticker, my guess is you have it. manufacturers aren't big on listing all the options you didn't get.

several ways you can verify this as well. one would be the build sheet, which you could request from the dealer by giving them your VIN (3.92's are listed as code DMHP). There is also the glove box sticker, diff tag (I can't find the tag on mine so I am not sure if that is a year specific deal or what). Also when you service your diff (which being an 07 I would think your at or over 30k miles and this should be done if not all ready done) they label the ring gear on the outside edge.

nateroach

 

What size wheels? If they're 20s and stock, the ratio is likely 3.92 17s generally got 3.55s

 

They are 20s. Thanks.

 

I did the diff a few thoussand miles ago so im not going to open it up again. I'll check the glovebox or the build sheet. From what everyone is saying, sounds like it got the 3.92.

With the bigger wheels/tires, does that negate the effect of having the better diff for towing?