differential change

Dandy Dan wrote:
From 3.73's I don't think I would go over 4.10's. Have you considered the cost to change out both rearends? I had the rearend changed out in a 1/2 ton I had and the cost was a little over $500. I have seen where some folks say they have paid close to 800-1000. My Dodge 4x4 has 3.73 gears in it and i didn't feel it was cost effective to do the swap. Good Luck in your decision.

Go drive a Power Wagon with the factory 4.56`s and see how you feel!

From 3.73's I don't think I would go over 4.10's. Have you considered the cost to change out both rearends? I had the rearend changed out in a 1/2 ton I had and the cost was a little over $500. I have seen where some folks say they have paid close to 800-1000. My Dodge 4x4 has 3.73 gears in it and i didn't feel it was cost effective to do the swap. Good Luck in your decision.

Bryan has towed his rig just about over and under any road around. Reality is, if you tow fine now, 4.56's may help or be a bit better.......at altitude, reality is, the ONLY thing that will help you is a turbo/super charger on a motor. THEN, and ONLY then will you not lose 2-3% of your HP per 1000 ft above sea level you go, to about 10K, then you start to lose the 2-3% like a natural aspirated motor. Gear changes do nothing to help you in the HP dept. Torque multiplication yes....

Just my 02!

Marty

Bryan,

Did you MPG go up or down while towing after you switched to 4.56? Have you pulled that rig over the Rockies?

Thanks for your input everyone. This is very helpful information.

I had 3.73 any early on switched to 4.30s. Popped a tooth on the pinion gear right ofter I got the weekend warrior (11,000 bone dry 18,000 max load) and went with 4.56. The V10 with 4.56 gears is a great combo!

It is a direct mathematical change. 3.73 to 4.56 will give 22.5% more rpm in all gears.

Or use this calculator: www.4lo.com

But you say it is towing good so I would be inclined to just go for it. If you felt like you are always between gears then the ratio change would make a big difference.

Haven`t had this setup to the Rockies... yet (Yellowstone/Tetons in 2015 hopefully), but have had it out to the Apalachians twice, Smoky mtns. one year and Disney another. I hit a few good long grades where I was passing some 40mph big rigs and one or two RV`s, had no problem keeping it at 50-55. I thought I posted my mileage? oh well. I average around 6.5-7.0, high 5`s in the mountains or a good headwind and low 7`s on flat ground with no wind. I would love it if I got 8mpg! at one point I was down to 5mpg and couldn`t figure it out. replaced everything fuel related, couldn`t get it to come back up. then I thought about it and learned about the ethanol killing power and mileage. I ran 93 octane on a trip and my power and mileage came back. now with the tuner I got an 89 octane tune and run 89 with no issues.

BTW, I edited my previous post because even I had a hard time reading it, the mileage was in there (somewhere) LOL! I separated a lot of it because it looked all jumbled together! I think it is easier to read now.

Nice report Dodge Guy but that ain't from the Rockies is it? I do believe your comment though, it should have came from the factory with at least 4.3's :W Maybe I missed your MPG report! I'm guessing about 8 towing on a good day.

Hello. you will love the 4.30`s. I swapped from 3.73 to 4.30 in my Excursion with the V-10. I will say without a doubt that it is the best thing that can be done to the V-10 for towing heavy! part of me actually says I could`ve went with 4.56`s and still be happy with everyday driving. the feeling with the 4.30`s was like driving a truck that weighed 2000lbs less!

The shifting felt better, wasn`t feeling like it was hanging in between shifts.

I`ve had the 4.30`s since 20k miles. I have 57k miles on the 4.30`s with no issues. just this year I purchased a 5 star tuner. mostly for the change in the factory shift strategy which anyone knows is terrible. it will change the shift points, increase line pressure, hold O/D a bit longer so it doesn`t kick out of O/D on the slightest incline or headwind. it can also increase HP and TRQ up to 20 more.

At the same time I replaced the factory Y-pipe which is severly knecked down supposedly to decrease some type of exhaust resonance. I haven`t heard any type of noise since changing it.

The X is now the towing machine it should`ve been from the factory. I am very happy with all the changes I have done and would do them again in a heartbeat!

My towing mileage increased by .5 mpg with the gear change.

The tuner gave me approximately a .3-.4 mpg improvement and I`m now at around 7mpg from my previous 6.5mpg (6mpg stock w/the 3.73`s).

I can now run in O/D at 65mph at around 2300rpm? IIRC and when it does kick to 3rd it is 3100rpm.