I have several questions about rear ends. I have a 97' 2500 4x4 with a 4:10 rear end in it. I would like to go to a higher gear ratio such as 3:73 or 3:55. Which would be a better bet for me to swap to? And is there a certain type of rear end that they put in 4x4's. The 4:10 is killing me on fuel mileage and my RPM. At 70 mph Im at 2500-2750. I need you guys help because I dont know a whole lot about rear ends. If anyboby has a rear with 3:73 or 3:55 gears that they would like to swap or sell please let me know or if you know of somewhere that I could get one reasonably priced. I would like to find one that is relatively local. I live outside of Bryan, Texas. All the hints, tips, and help I can get will be greatly appreciated. Thanks!

 

The other gear ratio mopar uses is 3:55's which is what my 97 has, running those at 75 mph I'm running almost exactly at 2k rpm. I avg. about 19 or 20 depending on how heavy my right foot is. Not to beat a dead horse but if you decide to change it remember to change both the front and rear gears or you'll tear the transfer case to pieces.

 

Thats what I really needed to know was if I needed to swap front and rear. I really don't want to sound stupid but i honestly don't know much about the gearing.Are the front end and rear end geared 4:10? If i need to swap them both what will it cost me? I need the fuel mileage difference and I want more top end than what I get with my 4:10. And the way yours is set up it sounds like you get way better fuel mileage and RPM than me.

 

Yes you would have 4.10 gears in both axles now. If you change one you will need to change both front and rear. Cost won't be cheap.

 

Ok so does anyone have an estimated guess on what it would cost me to swap both axles for 3:55 and does anyone know where i might could get some at a reasonable price?

 

See if someone will trade you.

Or check a gear shop.

 

I have a front ring and pinion that I will sell its 3.55 set out of a D60. Let me know if you interested, then you just need to find a rear set. let me know if your interested.

 

I had my 4.10's swapped out of both front and rear diffs and went to 3.55's. It cost me $1600.00 and have no regrets, still tows like a mule and I have a great cruising rpm on the highway

Dave

 

Did it help your fuel mileage any? Did you buy the rings and pinions and have someone do it for you or what?

 

I swapped my 4.10's out for 3.55's in November of last year. I bought used gears from a web forum, new Yukon full install kits with all new seals and bearings and found a local guy that helped me with the swap for a very reasonable rate since I wanted to help and learn how to do it. In the end - I spent around $700 then sold my 4.10's on Craigslist for $200 so my out of pocket cost was only around $500. This was super cheap!

When I called around to local shops to get prices on the install I was given prices in the $1500-$1700 range by the time I bought the install kits and used gears. Labor alone was about $1000. If you can fnd someone to give you a deal if you help out then that is the way to go imho.

I cannot really comment on any fuel savings because the day I did the swap it snowed and got cold and I didn't drive the truck much over the winter due to high fuel prices. I was hoping to gain 2-3 mpg and better drivability on the highway.

 

I saw a 1-2 mpg increase on the highway and a slight decrease around town, and $1600.00 was new ring and pinions, master install kit for front and rear. All I had to do was drop the truck off, lol

Dave

 

And I too sold old ring and pinions on the internet for $175.00