Re gearing after installing 35s, will it help with fuel econemy?

[MR.Hemi]

As it says in the title, will regearing from a 3.55 to 4.10 help with my fuel econemy. I am running 35s, I have searched the interwebs and there doesn't seem to me much information on the matter. So please tell me from your experiance.

 

[Beauregard7765]

Yeah it would help the mileage because it'll make it easier on the tranny.


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[MR.Hemi]

About how much of a gain do you think I will see, will it be worth the money ? How much does it cost?

 

[Hemi Ram]

I'm not sure exactly how it will effect you but driving around town I gained almost 2 mpg since swapping in 4.56 gears from the original 3.92s. I still am on stock 275 60/r20 tires. My highway mileage has suffered by 1.5 mpg but has increases by 2 mpg over stock when towing my boat at 70 mph. I attribute all of this to the fact that I give it less throttle input to get it rolling or maintain speed while towing or booting around town. Normal highway I lost mileage because of higher motor RPMs.
I would think changing your gearing to suit your larger tires would remove driveline strain and throttle input therefore possibly increasing your mileage slightly. Similar to my towing results.
Cost on my 3rd gen was about $1200 but this was front and rear Motive gears with Timken master install kits, an Auburn Gear limited slip for the back and every other bearing and seal that the kits didn't have to rebuild the axles while I had them apart. Did all the work myself.

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[brandonjansen]

As stated above, your city mileage will increase slightly; highway mileage will decrease. Overall you aren't going to make your money back in fuel savings alone but that's not the only advantage to swapping the gears. 4.10's would be easier on your entire drivetrain and make the truck a lot nicer to drive again too. I'm running 4.56's in my truck (with 37's). My average mileage went down slightly but it's still one of the best mods I've done to the truck for the increase in drivability alone.

You'd be looking at $2500-$3000 OTD to have a shop supply/install the gears for you. Depends on the shop and what parts you want to use.

 

[MR.Hemi]

Ok, thank you. I will have to save my pennies for a while.

 

[MR.Hemi]

I'm not sure exactly how it will effect you but driving around town I gained almost 2 mpg since swapping in 4.56 gears from the original 3.92s. I still am on stock 275 60/r20 tires. My highway mileage has suffered by 1.5 mpg but has increases by 2 mpg over stock when towing my boat at 70 mph. I attribute all of this to the fact that I give it less throttle input to get it rolling or maintain speed while towing or booting around town. Normal highway I lost mileage because of higher motor RPMs.
I would think changing your gearing to suit your larger tires would remove driveline strain and throttle input therefore possibly increasing your mileage slightly. Similar to my towing results.
Cost on my 3rd gen was about $1200 but this was front and rear Motive gears with Timken master install kits, an Auburn Gear limited slip for the back and every other bearing and seal that the kits didn't have to rebuild the axles while I had them apart. Did all the work myself.

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How hard is to change the gears yourself

 

[jbmobbs]

How hard is to change the gears yourself

Not hard if your patient and know what your doing, do your research first. I did 4.10s on my old 2500 my first set up came out very good......but I bought the best brand out there almost. It cost me a Lil more but well worth it......a year ago I put 4,56s in my current truck, no issues yet.....it's not hard. But do your research, buy quality parts and do not rush.......if your like me and get angry easy, take a break chill, maybe eat and come back and try again.....it's your patient and calm it shall work in your favor.....it's bought mine through randys ring and pinion. I bought yukon gears, bearings and red line break in fluid. And a pinion setting tool, buy it. Itll save you about 2 hours lol

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[MR.Hemi]

Not hard if your patient and know what your doing, do your research first. I did 4.10s on my old 2500 my first set up came out very good......but I bought the best brand out there almost. It cost me a Lil more but well worth it......a year ago I put 4,56s in my current truck, no issues yet.....it's not hard. But do your research, buy quality parts and do not rush.......if your like me and get angry easy, take a break chill, maybe eat and come back and try again.....it's your patient and calm it shall work in your favor.....it's bought mine through randys ring and pinion. I bought yukon gears, bearings and red line break in fluid. And a pinion setting tool, buy it. Itll save you about 2 hours lol

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Maybe there is a YouTube video lol. I rebuilt my 2nd gen dodge ram 1500 engine. You think if I can do that I will be capable of putting gears in. I have heard horor stories. I will look up randys rack and pinion to see what it would cost for the gears. I called a local shop and they will change them for 1456 otd

 

[jbmobbs]

Maybe there is a YouTube video lol. I rebuilt my 2nd gen dodge ram 1500 engine. You think if I can do that I will be capable of putting gears in. I have heard horor stories. I will look up randys rack and pinion to see what it would cost for the gears. I called a local shop and they will change them for 1456 otd

It's randys ring and pinion......there is only 3 stores in the USA. I just happen to live 30 min from one lol....The horror stories are from people who have never touched a car thinking they know what thier doing......it cost me like 600 0r 700 to do it my self. And it took me 4 days on my first one.....second one took me 4 to 5 hours.

And yes, if your capable of doing an engine this should be easy for you bud. It's just patients and shimming is all it is.....mine are silent going down the road on......they were on my 2500 too lol

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[Hemi Ram]

How hard is to change the gears yourself

Not extremely hard. It is something that takes a couple special tools and patience. Lots of patience. .. Expect to repeat the whole process at least a couple times before you get a correct contact pattern between the ring and pinion and it is one of those jobs that close isn't good enough. It has to be right or your gearset will be noisy or just disintegrate in a short period of time. The hardest part of the whole job is setting pinion depth. A combination of pinion depth in the ring gear and proper backlash setting is what gives you your contact pattern. Backlash is easy... pinion depth can be a pain because of the repetative work involved in adjusting shims.
Here is a tip that will help anyone. Buy 2 sets of pinion bearings. Hone one set out so they will snugly slide over the pinion shaft. Use these to set pinion depth. You don't have to press them on and off to adjust your shims. Once you have a good contact pattern and your pinion depth is correct then just press the new set of bearings on with the shims that you used with the other bearings. Bearings have very exacting tolerances so you can trust that 2 sets from the same manufacturer will be within .0002 of each other. Even stacking tolerances will equal less than a 1 thousandth shim.

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[MR.Hemi]

So I looked up the gears and watch about 20 videos and looked up a bunch of stuff about it. Come to find out my alignment was way off toed out about a degree and half on each side. After it was done I went from 13mpg to 17