02 22 passenger Shuttle. Pusher cummins with AT 545 Allison Any ideas?? Reverse is ok just no forward? Any help appreciated. Gil

 

Is this out of warranty with Allison? I would start at the NSBU switch. It is located at the drivers side of the transmission and what your linkage connects to. It should have 4-5 small electrical connectors running to it. Make sure the switch is moving when you place it in each gear. A few years ago, Allison had either a recall or a service bulletin out for faulty NSBU switches. I believe the old faulty NSBU switches are brown in color and the new updated is black in color.

Other than that, I cant help you much on the internals and what not since Freightliner doesnt let us do rebuilds on Allisons.

 

Does the engine race when you try to go forward? Like it's still in neutral?

You might check the shift linkage (or whatever it may be)?

 

if it is a pusher and has a AT545 , you probably have a stone bennet shifter on there and need to see if you are actually shifting at the trans linkage, if it is.... then you have internal problems in the trans , or if it is not shifting , they are easy to overhaul the shifter.