6.0 manual shifting

[BigCountry1492]

I have a 2018 2500hd work truck model when I attempted to use manual mode it only let me shift to 3rd is that common on work trucks or all of this year? Fuel mileage is about 10-11 mpg and that's babying it and my uncle had an 01 6.0 that got 11 no matter he was loaded or not? 

Any advice

[redwngr]

Manual mode limits the top gear, it does not 'force' upshifts.  It will perform a downshift if it calculates it can do so and not exceed maximum engine braking rpm. (which may be a higher rpm than max accelerating rpm)

 

Example - In M4 it will use gears 1 thru 4 as it sees fit, but will not use 5 and 6.

 

+/- button should let you select whatever one you like

 

Manual mode does change the way some of the engine and trans 'braking' modes work.

 

Might be worth a read, there are several pages of related info.

 

 

[SierraHD17]

Manual on these hooptys is just flat out misleading... It's not manual at all for the reasons given above.  Just call it like max gear mode... as that's all it accomplishes.  If you want real manual mode you need to get yourself into a Ford.  That said you should be able to select whatever gear you want it to upshift too and not just the first 3 unless they changed the strategy from 17 to 18

[BigCountry1492]

mine which is an 18  Only allows me to go to M3

[redwngr]

What are you trying when it won't switch?

 

Speed?

Action sequence?

[SierraHD17]

Must have changed.  I can downshift to whatever provided it doesn't over-rev and in M even sitting not moving can pick 1 through 6.

[Donstar]

I agree that manual mode is misleading.  It is a mode to allow some token input from the driver but nothing will be harmed if you simply leave it in "D".

[newdude]

17 hours ago, BigCountry1492 said:

I have a 2018 2500hd work truck model when I attempted to use manual mode it only let me shift to 3rd is that common on work trucks or all of this year? Fuel mileage is about 10-11 mpg and that's babying it and my uncle had an 01 6.0 that got 11 no matter he was loaded or not? 

Any advice

 

Just hopped into a WT at work.  Put the shifter into L (Manual mode is now L on 2016 or 17 and up).  I was able to hit the +- rocker on the shifter, and toggle it from L1, all the way to L6. 

 

When you are going into manual mode, are you doing it while driving?  I say this because when going into it while driving, manual mode automatically will drop the transmission down in gears (I assume its a programming thing related to passing power perhaps?)  So in Drive, 6th gear, if you drop to L(or M) it goes to L4 and puts the truck in 4th.  If you drop from Drive 5th gear to L, it goes to L4.  If you are driving and its in 4th gear, and you go to L, it goes to L3.  Owners manual has a chart explaining this visually.

 

My theory as to what you have going on, is that you are doing say 30-40mph, the trans is in 4th gear, and when you drop down to L, it goes to L3.  That's what its supposed to do, and the +- rocker on the shifter will allow you to change the gears it locks out.  Does your +- rocker on the shifter work?

 

As for MPG, its a 6.0 so expect no better than to average 10-14mpg.     

 

Description and operation from the owners manual (worth a read, the book should be in your glovebox...)

 

Quote

 

If equipped, Range Selection Mode helps control the vehicle's transmission and vehicle speed while driving downhill or towing a trailer by letting you select a desired range of gears.

To use this feature:

1. Move the shift lever to L (Manual Mode).
2. Press the plus/minus buttons on the shift lever to select the desired range of gears for current driving conditions.

With an 8-speed automatic transmission, hold the plus/minus buttons on the shift lever to select the highest or lowest range available for the current vehicle speed.

When the shift lever is moved from D (Drive) to L (Manual Mode), a number displays next to the L, indicating the current transmission range.

 

This number is the highest gear that the transmission will command while operating in L (Manual Mode). All gears below that number are available. As driving conditions change, the transmission can automatically shift to lower gears. For example, when L5 is selected, 1 (First) through 5 (Fifth) gears are automatically shifted by the transmission, but 6 (Sixth) cannot be used until the plus/minus button on the shift lever is used to change to the range.

 

In vehicles with gasoline engines, when the shift lever is moved from D (Drive) to L (Manual Mode), a downshift may occur. The gear that the transmission is operating in when the shift lever is moved from D (Drive) to L (Manual Mode) determines if a downshift occurs. See the following chart.

 

 

[SierraHD17]

Manual mode on my 2017 is an L.  It goes PRN D L 1.  1 of course locks it into first and or makes it back shift to 1st when it can.  So I guess it's not "manual" per say anymore lol 

[BigCountry1492]

Believe mine says P R N D M 1 But when I hit the m it displays L1 L2 L3 if I remember right

 

[BigCountry1492]

8 hours ago, newdude said:

 

Just hopped into a WT at work.  Put the shifter into L (Manual mode is now L on 2016 or 17 and up).  I was able to hit the +- rocker on the shifter, and toggle it from L1, all the way to L6. 

 

When you are going into manual mode, are you doing it while driving?  I say this because when going into it while driving, manual mode automatically will drop the transmission down in gears (I assume its a programming thing related to passing power perhaps?)  So in Drive, 6th gear, if you drop to L(or M) it goes to L4 and puts the truck in 4th.  If you drop from Drive 5th gear to L, it goes to L4.  If you are driving and its in 4th gear, and you go to L, it goes to L3.  Owners manual has a chart explaining this visually.

 

My theory as to what you have going on, is that you are doing say 30-40mph, the trans is in 4th gear, and when you drop down to L, it goes to L3.  That's what its supposed to do, and the +- rocker on the shifter will allow you to change the gears it locks out.  Does your +- rocker on the shifter work?

 

As for MPG, its a 6.0 so expect no better than to average 10-14mpg.     

 

Description and operation from the owners manual (worth a read, the book should be in your glovebox...)

 

 

I'll have too try that when I get back to town thank you

[sdeeter19555]

Just to point something out, you likely can make it hold and start out in 2nd...it's a traction aid to prevent wheel spin.

They must have changed since 2012, what you guys describe, mine doesn't do.

Steve
2012 2500hd 6.0l

[newdude]

6 hours ago, sdeeter19555 said:

Just to point something out, you likely can make it hold and start out in 2nd...it's a traction aid to prevent wheel spin.

They must have changed since 2012, what you guys describe, mine doesn't do.

Steve
2012 2500hd 6.0l
 

 

Yeps.  2013 and older, if you dropped to M at 60mph, it would go to M6 and not downshift. 

[SierraHD17]

25 minutes ago, newdude said:

 

Yeps.  2013 and older, if you dropped to M at 60mph, it would go to M6 and not downshift. 

I would love to copy that strategy into the newer TCM's.. dumping gears is retarded... I will decide how many I want to drop if any.

[2016HD]

Its an automatic transmission. They are designed so that you Cannot manually down shift into to low of a gear and over rev the engine and or cause all kinds of damage to the drive train!!  Its not like an old th350 or th400 with a shift kit installed where you could change to any gear you wish-and destroy driveshafts or the engine top end if you were not paying attention. 

My Trucks Manual mode works just as designed. It will lock out 6th gear, that is an overdrive gear any way and not needed if your trying to hold Certain rpm while towing.  It will allow me to shift down into any gear that i wish as Long as the engine RPM will not go over the rev limiter. This is what its designed to do. Allow a more versatile Autotrans compared to those of the past where you could only hold a gear so long until the Mechanical governor would shift into the next gear no matter what. Unless of course the valve body was modded for complete manual control. 

No disregard to GM but they should still offer a manual trans. However im better there were to many people who dont know how to drive blowing up drive shafts/clutches and rear differentials vs Automatic sales etc. 

Just my 2cs