W24 will not shift into OD

ROMAD · 04-16-2010, 04:36 PM

Noticed today that the RPMs were about 200 to high at 60 MPH and that the motorhome had not shifted in to OD (6th gear). Not sure what is going on as it has never done this before. The transmission is an Allison 2100 6 speed with electronic OD. Any ideas would be appreciated.

**"007"** · 04-16-2010, 05:09 PM

If everything but OD is working ok and if you have a switch on dash for OD maybe the wiring to it has come loose, I'd pull switch and check the wiring on back of switch.

edgray · 04-16-2010, 06:05 PM

Gene:
If you have a six speed, the dash OD switch should have 3 positions.
"Off" position= 4 th gear is ratio 1:1 (no overdrive)
middle position = 5th gear
"On" position = 6th gear

Both 5th and 6th do require an appropriate speed and load condition to be achieved before an upshift will occur.

Perhaps you were bucking a headwind, or needed more speed to get out of 5th.

Please let us know what you find out. Thanks, Ed

ROMAD · 04-16-2010, 07:15 PM

Quote:

Originally Posted by edgray

Gene:
If you have a six speed, the dash OD switch should have 3 positions.
"Off" position= 4 th gear is ratio 1:1 (no overdrive)
middle position = 5th gear
"On" position = 6th gear

Both 5th and 6th do require an appropriate speed and load condition to be achieved before an upshift will occur.

Perhaps you were bucking a headwind, or needed more speed to get out of 5th.

Please let us know what you find out. Thanks, Ed

OK, now I feel like an idiot! I did not notice that the switch had been moved and was on the center position. I do not know when it was switched off unless it happened when my wife was closing the window curtains. Anyway, thanks edgray and 007 for the input. Hope the pop wasn't too loud!