one-two shift?

[JimM68]

seems to take forever.

coach is an 08 monaco knight, cummins 8.3 350hp/1045ft-lbs, 6 speed allison.

coach winds up very quickly to 2200 rpm in first, then trans indicator light shows 2. rpm's drop maybe a hundred, moho is stillaccelerating strong.
After a couple seconds, the shift completes and the tach drops to 1600 or so.

All the other shifts are quick and positive.

I've taken to lifting off the throttle until it's firmly in second before going back to the floor with the go pedal.

Is this shifting normal?

[Mr_D]

First "shift" is probably the torque converter locking up. No harm in holding the throttle down.

[jimkate]

It's pretty much normal. Sometimes the shift into second can feel like two shifts. Sometimes you can wonder if it's going to miss the shift. It's an Allison. Short of trying to make it shift into reverse at 60 MPH (which I don't think you can do), I don't think there's much you can do to wreck that transmission. Used in industrial equipment, farm trucks, military snow plows, .....

[JimM68]

ok then, I'll just keep my foot on the floor and let it do it's thing then.
Thanks.

[Mike Canter]

I would say lifting the foot at the shift will confuse the transmission computer. Also will cause you to use more fuel and also confuse the motor computer. It would also unload the driveshaft and rear differential and then reload it again. Might cause longterm wear if you get to a million miles.

[JimM68]

thanks mike. I'll just keep my foot on the floor til she gets up to 65 then.
just weird that the 1-2 shift takes so long... Almost feels like the trans can't pull the torque down to lock into gear. But if you guys say it's normal, I can go with that.

[jimkate]

Mine is 13 years older than yours and has 140,000 miles on it, and the double shift in second gear hasn't seemed to hurt it one bit. I wouldn't worry about it.

[Mr_D]

Quote:

Originally Posted by jimkate Mine is 13 years older than yours and has 140,000 miles on it, and the double shift in second gear hasn't seemed to hurt it one bit. I wouldn't worry about it.

Since most people seemed to have missed it: The trans torque converter is locking up in there also, it can feel like a shift and the rpm's will drop also. Torque converter won't loak up in 1st gear and will unlock on a downshift to first also.. That's why your exhaust brake doesn't work in 1st also, the torque converter is freewheeling.

[Perry White]

AH, I don't thing the indicator should be showing a "2" if you have it in "D" it should show 6. I believe the indicator shows the highest gear setting. Like it shows "2" when engine brake on. Correct me if I'm wrong.

[jimkate]

Mine has a dual readout. The left readout shows the highest gear that has been selected. If you've left it up to the transmission, it will show 6. The right readout shows the gear that the transmission is currently in. As you accelerate, the right readout # will change as the transmission shifts.

[allisontec]

Early WTEC II systems had the dual readout on the shifter,WTEC III went to single readout,4th Generation went back to the dual readout.

[Perry White]

Nice

[JimM68]

Mine is as jimkate said. Left side indicates highest gear possible (6) right side indicates actual current gear (2 in this case)

Drove her to the storage lot yesterday, just feels weird.
Engine screaming at 2200 in first....
Trans indicates 2
Engine still screaming at 2200 but coach continuing to accelerate.
Count the 4, tach drops to 1700 or so, coach continues to accelerate.
Tach to 2200, indicator goes to 3, trans slams into third, tach drops to 1600....

If you guys say that's right good enuf for me.