Transmission Ratios?

[blahargoue]

I'm just curious since I tow a lot with my truck. Does anyone have any info on which gear in the new HD 6 speed auto (used with the 6.0 gas engine) is a direct 1 to 1 ratio? I'm assuming that both 5th and 6th are OD ratios. This isn't the Allision trans, its the one used with the 2007 and newer HD's with the gas engine.

[vranasaurus]

I'm just curious since I tow a lot with my truck. Does anyone have any info on which gear in the new HD 6 speed auto (used with the 6.0 gas engine) is a direct 1 to 1 ratio? I'm assuming that both 5th and 6th are OD ratios. This isn't the Allision trans, its the one used with the 2007 and newer HD's with the gas engine.

 

 

1

4.027

 

2

2.364

 

3

1.532

 

4

1.152

 

5

0.852

 

6

0.667

 

R

3.064

[blahargoue]

Thanks for the info. Looks like 4th is the closest to a direct 1:1 ratio.

[Ranger]

Jeez, that 1st gear must be a dog off the line...

[vranasaurus]

Jeez, that 1st gear must be a dog off the line...

 

I wish it had an option to start in second when unloaded. It's kind of a granny gear.

 

It shifts into second at about 5 MPH.

[plowking]

I think I read in the owner's manual that there is a way to start in second gear. Mainly used in winter to lessen chance of spinning on take off. plowking

[irengineer]

I think I read in the owner's manual that there is a way to start in second gear. Mainly used in winter to lessen chance of spinning on take off. plowking

 

You are correct. Move the shift lever to M and tap up to 2 (M2) (This assumes that you were not moving and your current gear was 1st when you move the lever to M).

 

In Normal Mode M2 you will start in 2nd gear from rest. If you depress the accel pedal fairly deeply you will initiate a 2-1 downshift.

 

In Tow Haul M2 you will start in 1st gear from rest.