Truckers Report Jobs

Find Trucking Jobs

Company Driver Company Driver Dry Van Dry Van Flatbed Flatbed Refrigerated Refrigerated Specialized Specialized Owner Operator Owner Operator
More Trucking Job Searches ⌄ Fewer Trucking Job Searches
⌃

Drivetrain setup mph and rpm's somethings up!!!

Discussion in 'Trucks [ Eighteen Wheelers ]' started by flc120, Oct 28, 2012.

Page 1 of 2
  1. Oct 28, 2012 #1
    flc120

    flc120 Heavy Load Member

    916
    122
    Jul 11, 2012
    Miami,FL (yeah i know :( )
    0
    well i got this new truck forthe oldman to work locally.

    heres the rundown it has a ntc350 big cam, rtf12510 trans and supposedly by whats read off the tag spicer 3.54 gears sitting on 11x24.5.
    truck does 55mph at 1500rpm with a newer silverado next to it to check speed.

    my problem is the truck doesnt feel as if it has 3.54's its like if the truck had 4.33's + i would think with this combo she would run 75 all day..

    could it be they changed the rear gears to something higher? or maybe the trans thats in there is a deep reduction trans with high gearing in it???

    i dont need to go faster just wondering if any of this sounds correct.
    also another thing i noted is that the factory tire size listed on the door jambs are 10.00x20 WTF????? its also listed for 50k GVWR does this mean anything.


    i can still haul 80k even if it says 50k on sticker correct? i mean it is a tandem axle truck, really its already been registered as a 80k vehicle as of yesterday so i guess not.
     
    flc120, Oct 28, 2012
    flc120, Oct 28, 2012
    #1
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  3. Oct 28, 2012 #2
    black_dog106

    black_dog106 Road Train Member

    1,786
    1,666
    Mar 29, 2009
    MA
    0
    black_dog106, Oct 28, 2012
    black_dog106, Oct 28, 2012
    #2
  4. Oct 28, 2012 #3
    flc120

    flc120 Heavy Load Member

    916
    122
    Jul 11, 2012
    Miami,FL (yeah i know :( )
    0
    dont understand what your asking.... weather its a overdrive or straight 10? its a straight 10 final gear is thrown to the rear of vehicle not up towards dash.

    what does the RT (F) stand for.... RT i have seen but the F i havent....

    plus whats the final drive ratio for my trans model i cant use the calculator without knowing that figure..

    seems as if this truck is geared like 4.33 or so just runs out to quick and when driving around on the street you pretty much have to throw all of the gears just to get to 40mph.
     
    flc120, Oct 28, 2012
    flc120, Oct 28, 2012
    #3
  5. Oct 28, 2012 #4
    Largecar359

    Largecar359 Road Train Member

    1,075
    1,324
    Aug 13, 2011
    New Jersey
    0
    Your trans is what's throwing you off. Unless someone marked the rears wrong. (unlikely). Rtf does not have an overdrive. And the f stands for front shifter plate mounting.
     
    Largecar359, Oct 28, 2012
    Largecar359, Oct 28, 2012
    #4
  7. Oct 28, 2012 #5
    Pedigreed Bulldog

    Pedigreed Bulldog Road Train Member

    7,737
    14,422
    May 7, 2011
    0
    Sounds about right with a 1:1 final gear in the transmission.

    It'll do 75 mph...at just a hair over 2000 RPM. I don't know that it'd be a good idea to keep it there all day, though...

    10.00x20 was a bias ply tube type tire probably on split rims. I'm guessing the hubs aren't original, because the 11R22.5 would be the replacement for them (with 1-piece tubeless rims, of course). To get the 24.5 rims to fit, the hubs would have had to have been changed.

    Yes, with a trailer. The 50K GVWR is that for the vehicle, not the combination. You've probably got 38K rears and a 12K steer axle. 38+12=50K GVWR, which is the max that vehicle can carry by itself within the manufacturer's specifications. That is NOT going to be legal, though, because you can only have 34K on a tandem. Hook up a trailer, though, and you can run 34K on a trailer tandem too and have 80K gross combination weight rating.
     
    Pedigreed Bulldog, Oct 28, 2012
    Pedigreed Bulldog, Oct 28, 2012
    #5
  8. Oct 28, 2012 #6
    DieselDummy

    DieselDummy Light Load Member

    173
    62
    Apr 1, 2012
    Willet,NY
    0
    sounds right to me, usually the NTC's run higher RPM's as they dont have the low rpm torque of a CAT. 3.54's with a straight non OD 10 speed is correct to me.





    trans identiy.jpg
     
    DieselDummy, Oct 28, 2012
    DieselDummy, Oct 28, 2012
    #6
  9. Oct 29, 2012 #7
    Ruthless

    Ruthless Road Train Member

    9,102
    90,281
    Aug 28, 2010
    The City.
    0
    Look at road rangers site. Enter your trans model in the search function. It should have the info about it (final drive and all other ratios) in the spec sheet. Might have to look a bit. As a previous poster has stated: sounds like a direct transmission (final drive of 1:1). It'd be highly unlikely that it's geared that low (4.33+) and setup in a truck you'd consider taking on the highway: if only because the motor in your truck NTC350 and rears that low with tires originally that size (10.00x20) would generally not be something you'd look at and think "road truck" it'd look a lot more vocational, with a body of some sort mounted on it. Just what jumps to my mind... :)
     
    Ruthless, Oct 29, 2012
    Ruthless, Oct 29, 2012
    #7
  10. Oct 29, 2012 #8
    tw1005tx

    tw1005tx Light Load Member

    60
    18
    Feb 24, 2011
    0
    Sounds like a older trk back in those years the ntc 350's were governed either 2100 or 1900 as I remember and 1500 hundred rpm was considered lugging the eng, way different then now.
     
    tw1005tx, Oct 29, 2012
    tw1005tx, Oct 29, 2012
    #8
  11. Oct 30, 2012 #9
    Quickfarms

    Quickfarms Heavy Load Member

    898
    236
    May 29, 2012
    Los Angeles, Ca
    0
    I second that.
     
    Quickfarms, Oct 30, 2012
    Quickfarms, Oct 30, 2012
    #9
  12. Oct 30, 2012 #10
    flc120

    flc120 Heavy Load Member

    916
    122
    Jul 11, 2012
    Miami,FL (yeah i know :( )
    0
    thats for sure ive been behind the wheel of my b-model cat ive forgot how these old NTC's run just been along time. my first 5 trucks all had NTC's i live and die by them but till i got what i thought was a rod bearing throwing CAT, its actually nothing like that and never dies down on hard pulls up hill no down shift necsseary.
     
    flc120, Oct 30, 2012
    flc120, Oct 30, 2012
    #10
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

    • Page 1 of 2