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Is going from 3.42 to 4.10 in DD tahoe w/ 285/75/16 OK?

Discussion in 'The Garage' started by atlantak-5er, Dec 3, 2003.

  1. atlantak-5er

    atlantak-5er 1/2 ton status

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    This is my daily driver. It feels like it could use a taller gear but I want to be able to cruise at 70 or so. Will I be alright? And will I have to get a new carriers for the 4.10 gear sets?
     
  2. MTBLAZER89

    MTBLAZER89 3/4 ton status Premium Member GMOTM Winner

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    I have 4.11's with 33's and it is just a bit low. You will have to use OD on the hi-way or you'll be reving above 3. Carriers should be the same /forums/images/graemlins/thumb.gif
     
  3. rockink5

    rockink5 1/2 ton status

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    It will be fine. I drive a 99 GMC 1ton full size van every day. It has 4.10 rear with 265/70/16 stock. At 70 that thing has just started to get going. /forums/images/graemlins/ignore.gif
     
  4. bigjbear

    bigjbear 1 ton status Staff Member Moderator

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    My wife's DD is a Jeep Grand Cherokee. It came stock w/ 3.73s and 215/75/15s. I'd say you'll be fine. It has full-time 4WD and a 318 (5.2) and gets 18 MPG on the highway all day long. However, stop & go uses a lot of gas.
     
  5. blasterD

    blasterD 1/2 ton status

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    With 285's 4.10's and a 4l60E? you would be turning approximately 1800rpm at 60mph, 2100rpm at 70 mph, 2400rpm at 80mph. IMHO this is well within DD range. I doubt mileage would suffer much if at all. My 99 Yukon has 3.42's and 285s It needs at least a 4.10, I might even go 4.56 (2000rpm at 60, 2330rpm at 70) if you plan on anything bigger than 285s in the future.
     
  6. atlantak-5er

    atlantak-5er 1/2 ton status

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    Thanks guys! This site is the best for quick and accurate info! I bet it will actually help my transmission out. I plan to stay w/ 285's; they get me where I need to go and I can still fit in parking decks!

    I am going to get an electric locker while I'm at it and go w/ the 4.10's.
     
  7. HarryH3

    HarryH3 1 ton status Author

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    The stock tires on a Sub/Tahoe were right about 30 inches tall. 285/75R16's are about 33 inches tall. 3.73:1 was the lowest gear that GM would put in the half-ton Subs and Tahoes. At 65 MPH, a stock truck with 3.73's and 30 inch tires would be turning 1900 RPM. With your 285's and 4.10's, it would be 1899 RPM at 65. /forums/images/graemlins/cool.gif So you'll end up with performance equivalent to a stock rig with 3.73's.

    4.56's will only raise the RPM to 2112 at 65. A 4.10 setup with 30 inch tires would run at 2089 RPM at 65, so 4.56's with your tires would be pretty close to a 4.10 setup with stock tires.

    I'd seriously consider the 4.56's, to make the truck a bit more fun to drive. /forums/images/graemlins/pimp1.gif
     

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