While looking at used trucks how will I know if it has the 3.55 or 3.92?

 

Plug the VIN into the page here and it will give you a build sheet of the factory equipment, including gears. I know it says Jeep, but ignore that. It works for any Chrysler product.

You can also ask the salesman for a build sheet print out. If he gives you a puzzled look, and asks what that is, you should probably ask for a different salesman. But if you are too nice for that, then ask him to request it from the service department, they should know what you mean.

Alternatively, you can look at the differentials underneath the truck. Front and/or rear pumpkins should have a sticker on them with the gear ratio. Found mine on the underside of the front differential. See the "3.55" below? Thats your gear ratio.


2009-2012 1500s will have a lot of 3.55 gear ratios, with a few of the 3.92 units sprinkled in, as 3.92 was an option. 2014+ will have a lot of 3.21 geared trucks, as the 8-speed reduced the "need" for 3.55 or numerically higher gears. 2013 was an odd year, where 3.21, 3.55, and 3.92 gear ratios were offered for the 8-speed trucks, but I don't believe 3.21 was offered for very many, if any, 6-speeds.

 

Thanks . Appreciate that. I'm not above crawling under a truck to take a look.

 

Mine has a sticker right on the axle, but as Jason stated you have a few options.

 

Yup, if you're lucky. I had no such stickers, and I was a little worried right away after purchasing my truck, because some 2013s and 2014s were sold supposedly with 3.55 or 3.92 axles, and FCA put in 3.21s by accident. Owners didn't know it unless they looked at the stickers on their axles/differentials. Their build sheets and window stickers said the ratio they paid for, but what actually was installed was different.

Very relieved when I found the 3.55 on my front.