2500 rear gear swap

[Demon-HeMi]

I have a 2008 ram 2500 hemi Heavy Duty with the g56 manual transmission, my problem is that the truck is just super low geared, im running around 2500 rpms at 70 mph, i bought the truck used so i dont know if the gears in the rear have been changed, but all the math and calculators ive used would suggest i have 4.10s in the rear but the build sheet i got from dodge says i have the 3.73 gears, like i said i have no way to confirm what gears i actually have in this truck for sure, but assuming i have 3.73 gears and want a more highway gear and get the RPMs down.

now before anyone says it, yes i know ill lose some torque and take off when towing, but im not towing heavy all the time and my biggest load is my show truck on a car hauler, but to give you an idea, empty, about 70% of the time i can start in 3rd gear and the truck take off like normal, 2nd if im going uphill, towing i almost never have to use first gear to get going, not even when i had a quad cab cummins on the car hauler, ill add ive been driving stick since i was 17 so i know what im doing when it comes to that.

hopefully someone here can have a good answer for me on this one, id really like to be able to cruise at 70-75 and the truck not be pushing 3k on the tach

 

[chrisp2493]

Does your smaller tires effect it at all? Aren’t you running 31” tall tires?


I Bleed Ram Trucks

 

[Demon-HeMi]

Does your smaller tires effect it at all? Aren’t you running 31” tall tires?


I Bleed Ram Trucks

im running a small tire but its factory diameter, i know bigger will help, but that will come after the lift, I know my build sheet says 3.73 but i would swear that its at least a 4.10 in this sucker, the previous owner used it to tow a 5th wheel camper so i know it was used for work, so it would make sense for them to swap


My OEM tires are 30.5" tall new and the tires i put on it in december are 30.43" tall, i took off worn tires so really there is no difference in my tires from stock

 

[chrisp2493]

I have a 33” tire, 3.92 and a .67 overdrive ratio. At 70 my rpms are at 1950 if that helps


I Bleed Ram Trucks

 

[Demon-HeMi]

My OD ratio in my G56 is .74

 

[Demon-HeMi]

Me driving:



One of the many online calculators ive tried:

 

[dexter]

hopefully someone here can have a good answer for me on this one, id really like to be able to cruise at 70-75 and the truck not be pushing 3k on the tach

I have 4.10 gears and am not pushing 3K rpms at 70-75

"but all the math and calculators ive used would suggest i have 4.10s in the rear but the build sheet i got from dodge says i have the 3.73 gears,"

If they did change the gears, they should have changed the speedometer also.

Use the link below to check.

https://tuning.americanmuscle.com/h...60743-How-do-I-verify-my-rear-end-gear-ratio-

 

[chrisp2493]

I have been under the impression that the rear end ratio will not effect the speedometer. Dodge uses a speed sensor in the rear axle so the gear ratio won’t effect it but changing the tire size will


I Bleed Ram Trucks

 

[Demon-HeMi]

I have 4.10 gears and am not pushing 3K rpms at 70-75

"but all the math and calculators ive used would suggest i have 4.10s in the rear but the build sheet i got from dodge says i have the 3.73 gears,"

If they did change the gears, they should have changed the speedometer also.

Use the link below to check.

https://tuning.americanmuscle.com/h...60743-How-do-I-verify-my-rear-end-gear-ratio-

You are a 4th gen with a diff motor and complete setup too, but i corrected that 3k statement with a pic of me driving, i bought the truck used, for all i know they could have done everything the correct way, did the speedo calibration when they did a gear swap, nothing on this truck has been hacked so who really knows, im just wanting to figure out what i have so i can get the rear changed, and if I really still have a 3.73 rear end, then i need to find what other gear options are available to me to get a better highway RPM

 

[Demon-HeMi]

Use the link below to check.

https://tuning.americanmuscle.com/h...60743-How-do-I-verify-my-rear-end-gear-ratio-

i will have to give this a try, thanks for the link

 

[BlkZrx]

That's showing 2400 rpm at 73. Not near 3000.. Can't remember what mine runs at that speed. Don't do interstate much. My 3.73 runs about 1550 at 60 mph.

I'd say you have 4.10 gearing.

Maybe somebody swapped it..

Sent from my LG-K540 using Tapatalk

 

[Demon-HeMi]

That's showing 2400 rpm at 73. Not near 3000.. Can't remember what mine runs at that speed. Don't do interstate much. My 3.73 runs about 1550 at 60 mph.

I'd say you have 4.10 gearing.

Maybe somebody swapped it..

Sent from my LG-K540 using Tapatalk

That 3k comment was just me venting more or less, right at the beginning of that post i say 2500 at 70 and thats not far off from where im at, but i agree with you that i think its been swapped, im gona try that trick with the driveshaft and then look into getting 3.73s put back

 

[dexter]

Me driving:



One of the many online calculators ive tried:

Does your truck ever kick into overdrive?

 

[G. Mcpherson]

Is there a Possibility to enter the Vin to find out what your Build sheet says.

 

[Demon-HeMi]

Does your truck ever kick into overdrive?

My truck is a 6 speed manual, that is what this truck calls overdrive...

that picture was taken in 6th gear cruising

 

[Demon-HeMi]

Is there a Possibility to enter the Vin to find out what your Build sheet says.

I have the build sheet, thats where why im questioning this in the first place, all the calculators im using suggest 4.10s but my build sheet says 3.73

 

[BlkZrx]

No tag on the pumpkin?

 

[Demon-HeMi]

No tag on the pumpkin?

TBH i havent gotten under there and really dug for it, this is just one item on my laundry list of things to do on my trucks and just started addressing it, this weekend im going to try the way shown above to see what happens to identify what i have, and im gona check and see if there are any markings on the axel to show that maybe they swapped the entire rear axel instead of just gears

 

[McBroom]

I have a 2008 ram 2500 hemi Heavy Duty with the g56 manual transmission, my problem is that the truck is just super low geared, im running around 2500 rpms at 70 mph, i bought the truck used so i dont know if the gears in the rear have been changed, but all the math and calculators ive used would suggest i have 4.10s in the rear but the build sheet i got from dodge says i have the 3.73 gears, like i said i have no way to confirm what gears i actually have in this truck for sure, but assuming i have 3.73 gears and want a more highway gear and get the RPMs down.

now before anyone says it, yes i know ill lose some torque and take off when towing, but im not towing heavy all the time and my biggest load is my show truck on a car hauler, but to give you an idea, empty, about 70% of the time i can start in 3rd gear and the truck take off like normal, 2nd if im going uphill, towing i almost never have to use first gear to get going, not even when i had a quad cab cummins on the car hauler, ill add ive been driving stick since i was 17 so i know what im doing when it comes to that.

hopefully someone here can have a good answer for me on this one, id really like to be able to cruise at 70-75 and the truck not be pushing 3k on the tach

4x4?


I Love My 2018 RAM 2500HD 4x4 6.4L. USMC (ret)

 

[McBroom]

A 3.55 or close to that will still have great pulling power and increase fuel mileage as well as lowering the rpms. I run 3.55’s in my 18 wheeler. I know that’s not much help just saying.


I Love My 2018 RAM 2500HD 4x4 6.4L. USMC (ret)