Will upgrading the 3.55 rear to 3.9 or 4.1 result in a performance gain in a '05 3.7? Does it matter that the truck has a selectable Tow/Haul feature? How much will this change out cost? Need a reliable response not a guess or maybe.

 

I went from 3.55 to 4.10 gears, BUT I have the 4.7 V-8

I paid $180 for the 4.10 Motive Gears
&
I also bought a Dana Trac-Lok LSD for $260 and had that installed too

It was $300 for the labor. They put in the LSD for free though since the stock differential has to come out anyways when you change the gears. I recommend having a shop do it though......the shop that did mine was specifically a Ring & Pinion shop.


Overall...I'm happy with it. Gas mileage hasn't really changed & it takes off a lot quicker now & responds better on the freeway.

 

Did it affect your speedo, or did you change the codes in the factory ecm. They told me anything above 3.91 affects the abs, but they didn't impress me at the dealership. Have you had any electronic issues with your computer? Thanks, Don.

 

Is your Dak a 4x4 or a 4x2. If 4x4, you'll have to change the ring and pinion in the front also to match.

 

Well according to a couple guys on Dakota-Durango that did the gear swap......the speedo is read off the tranny & the ring gear or something like that and it doesn't need to be changed in the computer

So no I didn't have them change the settings in the computer & like I said in the other post....my truck runs perfect. Just changed the gears & added a LSD, and the speedo reads accurate

Here's a post from Dakota-Durango:
http://www.dakota-durango.com/forum/...ad.php?t=14555