LatrobeHO

Just bought my 03 HO 3500 SRW 4x4 6-speed, and it has the 4.10 gears. Before you ask, it was the only one in hundreds of miles with the options we wanted, so we didn't have a choice, and we couldn't wait to special order one.

Is it possible to have the gears changed from 4.10 to 3.73 at the dealer? Anyone have an idea on the complexity and COST of such a change?

I won't be needing to tow anything near 10,000 pounds for quite a while and would prefer the lower RPM's and better mileage.

Thanks for your input!

erics76

I don't know much about the new axles, but for the most part, it is very complex and expensive to change and set-up gears correctly. I had both axles changed in my jeep, and the labor was over $1000. That was at a aftermarket jeep shop. I'd hate to see how much it would be at a dodge dealership.

PADZZ

Best is to find someone that wants 4.10 and switch w/ them. Someone on this site or the other site did the switch and both came away happy campers.

bulabula

Drive it for a while before you make the big jump. You may find that it isn't that big of a deal.

You'll save some revs on the superslab, and gain just a little mileage but not that much. With two pumpkins to swap, you'll have to do ALOT of miles before any fuel mileage savings will pay for the swap out.

It'd be cheaper (and better looking) to put some 35's on it to lower the rev's.

DF5152

[quote author=bulabula link=board=20;threadid=17922;start=0#msg167742 date=1059959055]
Drive it for a while before you make the big jump. You may find that it isn't that big of a deal.

You'll save some revs on the superslab, and gain just a little mileage but not that much. With two pumpkins to swap, you'll have to do ALOT of miles before any fuel mileage savings will pay for the swap out.

It'd be cheaper (and better looking) to put some 35's on it to lower the rev's.
[/quote]
I agree you are only talking 2 to 3 hundres RPM's difference. get urself the tires and if u ever really need the little extra pulling power you can switch back to the old tires.

Bikinaz

Where are you located. I'm in Phoenix. If you have the no spin axle, I'd trade with ya.

deere nut

I get 22 mpg driving 70 (not pulling). my dad just bought a truck just like mine but with auto and 3.73's. he gets 19 mpg at 70. So why switch? Even if you are not pulling 10,000 lbs the gearing will really help on inclines and hills/mountains. I just made a 6,000 mile round trip from La. to Az and Ca. pulling 5,000 to 12,000 lbs. 2600 rpm was the sweet spot (80 mph) and i RARELY had to downshift (only when pulling over 10,000 and grade of 5% for several miles). I was really impressed and my truck is bone stock.

Luke S

22mpg with 4.10's, dear god! I got the HO/48re w/4.10's and the best I can do at 70 mph is about 16-17mpg??? ??? :

Bikinaz

You know I'm kind of confused. I have the auto and 3.73 gears. I had about 700 pounds in the bed for a 300 mile trip, I never went over 70 MPH. Matter of fact most of the time I was running less than 65 MPH. I ended up at 17.63 MPG. I’m I missing something? I filled the tank on the exact same pump to the exact same spot in the neck of the tank. Maybe it’s because I have less than 1000 miles? There was some hills involve, but it wasn’t like I was in Silverton Colorado. Regardless, I figure if I’m getting better mileage than my last truck I’m happy.

Mopar_Mudder

I agree guys, I think deere nut is a smokin somthing, LOL

I only got about 16.8 normal driving back and forth to work in the 60 mph are, at 70 I know it will be a little less. 22 is unheard of. I have mods done to mine also which raised the mileage from what it was.

LatrobeHO

Someone mentioned that I could put a set of 35's on the truck and that would negate some of the effects of the 4.10 gears. What exact tire(s) are you referring to?

jsr21

Don't change out your gear set..it would cost you a fortune. I have 4.10's and really like them. However, what you need to do is install tires that are approx 10% taller than your stock ones..thus lowering your effective gear ratio by the same(10%)....so 4.10's less 10% work out to around 3.70's. I would run it like it is and when the tires wear out make the switch if you like....there is only about 200 rpm diff between the two gear sets(10% again)..like 2200rpm to 2000rpm....hope this makes sense, I'm a little fuzzy this morning..lol

Jonesey

[quote author=Cummins Luke link=board=20;threadid=17922;start=0#msg167852 date=1060002740]
22mpg with 4.10's, dear god! I got the HO/48re w/4.10's and the best I can do at 70 mph is about 16-17mpg??? ??? :
[/quote]

I can get 22 MPG with 3:73s. All I have to do is find a long downhill stretch and reset the overhead computer at the top, throw it into neutral and let her coast. It is no problem to see 25 MPG at the bottom of the hill. Now that's some MPGs. ;D

Hoss

[quote author=deere nut link=board=20;threadid=17922;start=0#msg167815 date=1059974097]
I get 22 mpg driving 70 (not pulling). my dad just bought a truck just like mine but with auto and 3.73's. he gets 19 mpg at 70. So why switch? Even if you are not pulling 10,000 lbs the gearing will really help on inclines and hills/mountains. I just made a 6,000 mile round trip from La. to Az and Ca. pulling 5,000 to 12,000 lbs. 2600 rpm was the sweet spot (80 mph) and i RARELY had to downshift (only when pulling over 10,000 and grade of 5% for several miles). I was really impressed and my truck is bone stock.
[/quote]

Are you SURE you have the 4.10's?? I'd have to go drive it again to verify, but I think that MY truck hits about 2600 RPM's at 80 MPH...and I KNOW I have the 3.73's. Not to mention the 22 MPG @ 70 MPH. The best I got was with the cruise control on at 70 for about 500 miles....empty.....21.8 MPG.

Posm

Are you sure the 4.10s hurt mileage. I have watched posts here and other forums for a couple of years and there seems to be NO correlation between rear end ratios and MPG. I see much more differences in MPG between individuals with the same truck! It may be truck variations or it may be driving style differences. I think it is the latter.
Some one with the instant over head computer could test this very easily. Do a test run in high gear. Then, reset the computer and repeat this test in the next lower gear running at the same speed. I bet if this test was repeated several times the differences would be very small. The differences between OD and direct would be much great than between 4.10 and 3.73s. I submit the difference in wind drag at a higher speed makes the majority of difference. It takes much more HP to run the rig at 75 than it does at 65. Just watch your boost guage, it'll tell you. The TDR had a write up on fuel consumtion at a given HP requirement. The consumption was very steady from 1800 RPMs to 2500 Rpms, if my memory serves me correctly.
That being said, I was in South Dakota last month and man do they fly out their. We took my buddies Ferd and ran 85 on I-90 the whole way out. We met a county deputy doing over 100MPH and he just waved at us. I would want to have the 3.73s out there to run that kind of speed.