Jump to content

Welcome To Mopar1973Man.Com LLC

We are privately owned, with access to a professional Diesel Mechanic, who can provide additional support for Dodge Ram Cummins Diesel vehicles. Many detailed information is FREE and available to read. However, in order to interact directly with our Diesel Mechanic, Michael, by phone, via zoom, or as the web-based option, Subscription Plans are offered that will enable these and other features.  Go to the Subscription Page and Select a desired plan. At any time you wish to cancel the Subscription, click Subscription Page, select the 'Cancel' button, and it will be canceled. For your convenience, all subscriptions are on auto-renewal.

4.11 Rear end

Posted

Finally got it done, the most awesome thing Ive done to this truck. Say good bye to high egt's and hello to fuel mileage and power. She's a power house now.

 

    • Like 2
    • Replies 18
    • Views 1.8k
    • Created
    • Last Reply

    Top Posters In This Topic

    Popular Days

    Most Popular Posts

    • Mopar1973Man
      Mopar1973Man

      Amazing how proper ratio really helps out. 

    • Tractorman
      Tractorman

      I'll bet that is a powerhouse!   - John

    • 01_Cummins_4x4
      01_Cummins_4x4

      235/85/16 = 31.7x9.3/16 245/75/16 = 30.5x9.6/16 265/75/16 = 31.6x10.4/16   You're pretty much in line with the 265/75/16, just an inch narrower tire.   What are your RPMs

    Posted Images

    Featured Replies

    • Owner
    On 10/11/2024 at 9:41 PM, jlwelding said:

    Finally got it done, the most awesome thing Ive done to this truck. Say good bye to high egt's and hello to fuel mileage and power. She's a power house now.

     

    Amazing how proper ratio really helps out. :smart:

    • Like 1
    • Author
    On 10/12/2024 at 9:17 AM, Tractorman said:

    :thumb1:

     

    What tire size are you running?

     

    - John

    LT235-85-R16

    On 10/12/2024 at 9:17 AM, Tractorman said:

    :thumb1:

     

    What tire size are you running?

     

    - John

    235-85-R16

    On 10/19/2024 at 7:05 PM, jlwelding said:

    235-85-R16

     

    I'll bet that is a powerhouse!

     

    - John

    • Like 1
    • Staff

    235/85/16 = 31.7x9.3/16

    245/75/16 = 30.5x9.6/16

    265/75/16 = 31.6x10.4/16

     

    You're pretty much in line with the 265/75/16, just an inch narrower tire.

     

    What are your RPMs at 60 mph?

    • Like 1
    • Author

    2k at 60 ,  egt's dropped 200 degrees. I was 800 degrees at 60-65. Now 600 - 625. I pulled 21k loaded with hay and it didn't faze it a bit. The hottest egt's got was a little over 1k, course the turbo helped a lot.

    • Owner
    On 10/21/2024 at 4:11 PM, 01_Cummins_4x4 said:

    235/85/16 = 31.7x9.3/16

    245/75/16 = 30.5x9.6/16

    265/75/16 = 31.6x10.4/16

     

    You're pretty much in line with the 265/75/16, just an inch narrower tire.

     

    What are your RPMs at 60 mph?

    Correct. 

     

    3.55 and 245s is 2k RPM at 66 MPH for my setup. Which is 3.69 final ratio.

    • 2 months later...

    I have 4:10s 265/75/16 tires auto w/HD Overdrive 4x4 dually '99 . At 75 mph im at 2600+- rpms. Bought new on 99 had 3:55s and with 265/75 was slow as ****. So $12-15k later not so slow anymore

    • Owner

    I'm at 3.69 final ratio. 245/75 R16 tires vs. 265/75 R16 tires (stock). But I'm 3.55 geared axles. At 82 MPH turning exactly 2,500 RPM. Still getting upwards of 20 MPG. High RPM is not a issue and is way more efficient than 3.55 gears on 31.6" tires (265/75 R16) and use a 245/75 R16 which is 30.5" inch tires.

     

    Beast can fry the tires in every gear but 5th gear.

     

     

    Edited by Mopar1973Man

    • Like 1

    So,I have an 01 with nv4500. 4x4. When I bought this thing a year ago it needed tires real bad . I bought it in Couer d alane, ID with 3 may pops and a will pop lol. Looking to buy tires before I drove I it home to Wa coast I ignorantly looked for 35’s and rims and would have bought them if they would have had them in stock. Thankfully I ended up buying stock size L285/75R16 on to the stock rims. Did all of these pick ups come with the same rear end gear ratio? How can I figure my gear ratio?

    30 minutes ago, kbf98520 said:

    Thankfully I ended up buying stock size L285/75R16 on to the stock rims.

     

    The stock tire (listed in the driver side door jamb) is 245/75R16.  The trucks were actually sold with 265/75R16's.  Your tire is slightly larger diameter than stock.

     

    30 minutes ago, kbf98520 said:

    Did all of these pick ups come with the same rear end gear ratio?

     

    Trucks came with either 3.55's or 4.10's.

     

    30 minutes ago, kbf98520 said:

    How can I figure my gear ratio?

     

    My truck has 3.55 gears and 245/75R16 tires.  In direct 1:1 gear ratio (5th gear with my NV5600) , my tach reads about 2000 rpm at 50 mph.  If I had 4.10's, the tach would probably read about 2200 rpm.

     

    Since you have an NV4500, you would need to use 4th gear (1:1 ratio) to make the same comparison.  Include a minor adjustment for your slightly larger tire diameter.

     

    - John

    Edited by Tractorman

    1 hour ago, Mopar1973Man said:

    This is a older photo but 80 MPH to 2,450 plus or minus a few RPM.

     

    Since it is not in his signature, I will add that Moparman's transmission is a NV4500. 

     

    I believe he is in 5th gear and running 245/75R16 tires in his photo.

     

    - John

    Edited by Tractorman

    • Owner
    5 minutes ago, Tractorman said:

     

    Since it is not in his signature, I will add that Moparman's transmission is a NV4500. 

     

    I believe he is in 5th gear and running 245/75R16 tires in his photo.

     

    - John

    Correct. 

     

    NV4500 with 5th gear at 0.75:1 ratio.

    245/75 R16 tires which are 30.5 inches.

    Axle gear set 3.55:1.

    • Staff
    2 hours ago, kbf98520 said:

    How can I figure my gear ratio?

    There is a tag in the glove box with the rear end size.   If the tag has disappeared, you can call the Dodge dealer's parts or service department and ask for the info from the factory build sheet.

     

    This web site has an app to calculate final drive ratio with gear/tire size info.  

    https://tiresize.com/gear-ratio-calculator/

     

     

    • Like 1
    • 3 weeks later...
    • Author

    If y'all would like to watch the entire rebuild of this Dana 80, my builder just got it edited and you can watch it on Facebook or YouTube. Just search Stratemann Automotive. Bring some popcorn you gonna need it.

    • Thanks 1

    Oof 16” tires…

     

    Cant run 3rd Gen brakes with those.

    • Owner
    On 2/5/2025 at 9:30 PM, Mace said:

    Oof 16” tires…

     

    Cant run 3rd Gen brakes with those.

    Wouldn't wanna. 3rd Gen brakes add more rotational mass. Yeah I'm trying to fix my 3rd Gen right now it barely gets 14 MPG empty. 

    Edited by Mopar1973Man

    Go to topic listing

    Did This Forum Post Help You?

    Show the author some love by liking their post!

    Welcome To Mopar1973Man.Com LLC

    We are privately owned, with access to a professional Diesel Mechanic, who can provide additional support for Dodge Ram Cummins Diesel vehicles. Many detailed information is FREE and available to read. However, in order to interact directly with our Diesel Mechanic, Michael, by phone, via zoom, or as the web-based option, Subscription Plans are offered that will enable these and other features.  Go to the Subscription Page and Select a desired plan. At any time you wish to cancel the Subscription, click Subscription Page, select the 'Cancel' button, and it will be canceled. For your convenience, all subscriptions are on auto-renewal.