Taking the Plunge (Gear Swap)

Thanks for the report. Sounds like it was a good move for you.

I have had a couple thousand miles on the new 4.30 gears, and I can report that they did make a difference, strong but subtle.

Most noticed is acceleration in town, and the ability to hold 5th gear while hauling significantly longer and up highway inclines that I could never hold before. I actually gained the use of cruise control while hauling because it hold gears so much better.

I can also use 6th gear on downhill and flats while hauling, so in essence, I think I gained a full gear across the range, whereas before 6th was essentially useless hauling, and 5th practically useless on anything but flat ground or the slightest of inclines.

That said, with my stock 17" tires/wheels, I think the sweet spot would be 4.10's, as the 4.30 is a little revvy, but that is probably because I am so used to the 3.73's that I have towed with since 2011.
Gman

Did my Ford V-10/F350 a few years ago...from 3:73 to 4:30......hat a difference! Pulling a 36' 5ver....it holds the gears longer and my mileage went up empty and pulling.

bpadamson wrote:
I did the 3.73 --> 4.30 after one year pulling our 5th wheel. Wife was deployed last year and I had no trips planned so changed them out last fall. This year we hope to give them a good test. What I know so far is that it pulls better in each gear, and that has resulted in better mpg by 1-2 over several tanks. Looking forward to spring so we can get it out of the snow. I had dealer do the swap and they did front axle shafts and all seals; plus 36,000 mile guarantee.

Sounds good. I might go ahead and swap mine before our next trip April 1st.

I have had 3 Dodge cummins trucks with 3:54's and one with 4:10's, they all the ones with a 5spd trans got close to the same mpg, the one with the 4:10's got 1-2 better towing and you could tell it was so much easier on the truck when pulling a load.

I think you will be happy.

I did the 3.73 --> 4.30 after one year pulling our 5th wheel. Wife was deployed last year and I had no trips planned so changed them out last fall. This year we hope to give them a good test. What I know so far is that it pulls better in each gear, and that has resulted in better mpg by 1-2 over several tanks. Looking forward to spring so we can get it out of the snow. I had dealer do the swap and they did front axle shafts and all seals; plus 36,000 mile guarantee.

It's amazing how much of a difference it makes! Your around town mileage should go up, along with towing mileage. Definitely post back after your first tow.

Grodyman wrote:
While I have yet to tow or haul, I am encouraged by the results so far.
Gman

When is your next pull? Can't wait to hear your thoughts on the different feel with some weight.

Thanks for posting back and add that engine braking will also be a bit better with those 4.3's...of course dependent on which tranny gear you are in

Since less throttle than before...hoping you gain a bit more in MPG too (when towing)

So far with just around town driving, the gears made a significant difference. The truck gets going and up to speed with a lot less throttle. I feel significant power increase in all gears. I can now start and get up to speed with all the little 4-bangers that are always in a big hurry to make a point to zoom around me, no problem. And this with a big heavy dually.

While I have yet to tow or haul, I am encouraged by the results so far.
Gman