What is the best transmission for our trucks?

Discussion in 'The Coffee Shop ~ Chit Chat' started by PantheraUncia, Sep 14, 2012.

  1. PantheraUncia

    PantheraUncia Epic Member 5+ Years 1000 Posts

    Transmissions are not cheap, they are a major component in our trucks. Some of us have trucks because we enjoy them, others use them to tow stuff, etc.

    What is the best transmission?

    GM has traditionally used a 4 speed tranny. Then when the diesels came back they put a 6 speed allison on them.

    Now you get a GM 6 speed on a 1500 in the newer trucks. Talking to various people, they tell me that you don't need a 6 speed tranny, there are more parts, more things that can go wrong and they are more expensive to fix.

    Well as an example (I am talking about any type of truck in the world, not just small ones like we truck regularly).

    The Caterpiller 797 series dump trucks use a 7 speed transmission. Most 18 wheelers have more than 6 or 7 speed transmissions to:


    That is the latested "Eaton" 18 speed transmission for 18 wheelers. I have an Eaton G80 in my truck for the rear diff.

    Would it be wrong for Eaton, GM, Allison, etc to make a 1/2 ton transmission with 18 speeds?

    Companies like Caterpiller, and Eaton, where they are working with the latest technology to move heavy loads with the best possible fuel econ, know what they are doing.

    5 years ago if I asked for a 6 speed in my silverado, I would get laughed at.

    In 20 years they might have a 12 speed, etc, but I would get laughed at asking for one now.

    Well, having more speeds or ratios, is it better? Put an 18 speed in my truck now :)
  2. tbplus10

    tbplus10 Epic Member Staff Member 5+ Years 5000 Posts Platinum Contributor

    More gears ='s better selection to fine tune for optimal performance and mileage.
    Yes more gears does mean more moving parts but with advances in technology some of the failure points have been worked out to produce a stronger less failure prone product.
    Do we need an 18 speed in a 1/2 ton truck?
    Need I dont know, want, maybe some days, especially on a long road trip where you dont want to stop as often.
    I'm still happy with the old TH400 3 speed, throw a ranger overdrive unit behind it and it's nearly indestructable and gets decent mileage.
    While you could probably get good fuel mileage out of a transmission with that many gears it would be shifting all the time back and forth, unless you were traveling on a flat straight road, and had the cruise control on to maintain a set speed.
    I recently had a chance to drive a new Dodge Charger with an 8 speed automatic transmission and V-8 across Texas newest toll road set to open in November (85mph for all the speed freaks) and while I can say with the V-8 engine it got terrific mileage even the slightest change in road elevation made it shift up or down, this was particularly annoying to me since it wasnt shifting smooth (the car had a diagnostic bug that was fixed with a scanner by a Chrysler rep) and while the latter part of the trip it shifted smoother I could still tell every time it shifted. One thing to be noted was higher speeds made the transmission shift up or down more, i.e. if I was traveling at 65 it was more likely to maintain a set gear for a few miles vice traveling at 85 where it shifted up and down 5 times in less than 3 miles. Now if this was a manual transmission I wouldve been worn out with all the up and down shifting.
    I've driven big rigs off and on over the years, mostly 7/8 speed trucks but I have had a chance to drive 12/15 speed trucks, being these are manual transmission trucks my personal opinion has always been the more gears the more you work your self, with less gears I've always chose to adjust my speed instead of shift for a better gear, a little less work on the driver.
    CAFE standards arent getting easier so more gears appears to be one way mfgr's are battling new standards, I believe we could see 1/2 ton trucks with 10/12 speed automatic transmissions in the future.
  3. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    [MENTION=14295]tbplus10[/MENTION], I'm curious what you'd recommend if overhauling/replacing a 4L60E in a NBS truck. I'd like to see improvement in how much power can be handled as if/when my engine has issues I'll make some improvements, there. I'd also love to see something that delivers more fuel economy when in overdrive.

    Sadly, I'm transmission-stupid ... and still learning.
  4. Conlan Rose

    Conlan Rose Epic Member 5+ Years 1000 Posts

    [MENTION=50075]SurrealOne[/MENTION] a good almost direct replacement for the 4L60e is its slightly beefed up and modified twin the 4L65e it can handle more torque and horsepower but has the same gear ratios as the 4L60e so no promise on improved mpg.

    Personally I love my 4L60e tranny its amazing for being 16+ year old tech but having smart shifting and semi-variable shift points.
  5. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    Can you define what isn't direct?
  6. Conlan Rose

    Conlan Rose Epic Member 5+ Years 1000 Posts

    Well I had to double check the site about it and Yah same size and mounting from what I can tell may breed to change the tranny mount, but other than that should work.
  7. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    I was worried about electrical compatibility. :)

    Improvements I've read make sense on a 4l60E are:
    * 5 pinion planetary gear
    * 'Beast' sunshell from SPX
    * 13 vane pump w/ TransGo pump rings
    * B&M Shift Kit
    * Corvette Servos
    * TransGo Boost Valve
    * A new reverse drum
    * Alto carbon wide powerband
    * 'Raybestos Max Pac' input drum (8 clutch set)

    That's all greek to me. Any comments on those items?
  8. tbplus10

    tbplus10 Epic Member Staff Member 5+ Years 5000 Posts Platinum Contributor

    Unfortunately the only way to achieve better fuel economy in overdrive would be to change to a transmission with better gearing or change the diff gears.
    Assuming your happy with the diff gears the choice would be a different trans.

    4L60E and 4L65E share gear ratios so a swap to the 4L65 would gain you a stronger transmission
    1 2 3 4 R
    3.059 1.625 1.000 0.696 2.29

    4L80E is an even stronger transmission but unfortunately the final drive wouldnt help fuel mileage
    1 2 3 4 R
    2.48 1.48 1.00 0.75 2.07

    The ideal choice would be the Hydra-matic 6L80 with a set of stand alone computers to manage engine and transmission functions.
    1 2 3 4 5 6 R
    4.03 2.36 1.53 1.15 0.85 0.67 3.06

    The 6L80 has a nice deep first gear to help get taller/heavier wheels rolling and does more to spread the pattern out rather than really go high.
    But even though you didnt mention money being no object I'll assume it would play a big part in choices so the best bang for the buck will be using the parts you listed to rebuild your present transmission, and when funds become available look at an overdrive unit, Ranger has a real nice unit and theres a couple others available that work about the same.

    I used the Ranger O/D on a Chevy truck before, 74 Chevy 1/2 ton long bed 4x4 TH400/350.
    It improved the fuel mileage by about 40% on long highway trips, in town it wasnt much use because we barely got to use it.

    The parts you listed are all good parts and just about standard to build a 4L60 into a bullet proof trans, but unfortunately no one offers a kit to change any of the gear ratios, especially the final drive and thats where your gonna get any fuel mileage improvement.
  9. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    Two questions:

    1. Any other parts I should consider during a rebuild of the 4L60E?
    2. The ranger overdrive units I'm finding in searches are for manual transmissions. There's something that works with an automatic tranny?
  10. tbplus10

    tbplus10 Epic Member Staff Member 5+ Years 5000 Posts Platinum Contributor

    For major parts you've got a good list, you know thats actually about 60% of the transmission you'll replace, right. But if you want a bullet proof trans it's whats required.

    Forgot Ranger only likes Manual transmissions or 3 speed autos, they dont recommend using their units on 4 speed autos. http://www.high-impact.net/transmission_and_gear/overdrive_conversions.htm

    To retain a 4 speed auto you have to look at Gear Vendors, another good company in the overdrive world. http://www.gearvendors.com/

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