4 speed or 5?

[Tikvah]

I have an MCI with a 6V92TA and the Alison 740 (I think)

My shifter shows 4 speeds, but when I drive I absolutely can count 5.  I think about it so much that I find myself counting almost every time I start from a start.

What's the deal?  A friend said it has something to do with the torque converter, but I definitely feel 5 distinct shifts and changes in the RPM.

Experts?

[chessie4905]

  When the converter locks up in these transmissions, you can definitely feel it, just as if it is a shift. Just note the  road speed  gain before and after a shift. The lockup shift change will only amount to a couple of mph compared to the rest. My V730 definitely feels like a four speed because of it, even though it is only a three speed. If it was truly a 5 speed, it should feel like a 6 speed.

[Iceni John]

If you have a 4-speed HT740 it will seem like you have a 5-speed  -  you may be feeling when the TC locks in 2nd.   Most HT740s shift 1C-2C-2L-3L-4L   On my HT740 the lockup feels harder than the actual shifts.   Curiously, your Felsted T-handle shifter is the opposite way of mine, but that should not change how the transmission shifts in Drive.   If you look at the side of the transmission there will be an Allison plate with the model number stamped on it  -  I think it's on the driver's side?

John

[chessie4905]

   I think the vice grips may be giving you that extra gear.......

[Melbo]

On my ZF trans I have LEDs on the shift pad.  They light up when the solenoid for each gear is engaged.  I also have a light to let me know when my trans lock up solenoid is engaged and another set to let me know if I am in high or low range on my retarder and when it is engaged.  So even though I have a four speed transmission I can see when I go from 2nd to 2nd lockup and if I'm light on the fuel it sometimes will drop out of lock up as it shifts to third and then go into lock up mode again so I can get the sensation of a 6 speed transmission with my four speed.  Cheaper to imagine that I have a six speed than to actually have to buy one.  Just enjoy the 5 speed sensation and pretend like you got a bargain with the bonus shift.

HTH

Melbo

[HB of CJ]

And ... to further muddy up the waters, a very few HT740 heavy fire apparatus's like airport crash trucks, (way back in the day) had a special valve body that locked up the tranny in all four gears.  I got to drive one.  Actually sounded and felt like an eight speed transmission. 

1C-1L-2C-2L-3C-3L-4C-4L.  At first I though it was a Powershift tranny of some sort, but the factory apparatus rep explained it all to us.  Another successful way of accelerating very heavy machinery quickly.  Fuel mileage or slowing down or stopping was not a consideration.