10 Speed Meritor Trans. No Shift from Low to High or back

2003 Volvo Day cab

M11 Cummings Diesel Engine

10 Speed Meritor Transmission ( electric over air ) MO-15G10A-M15



Transmission rebuilt less then 10000 miles ago



Truck will not shift Low range to High range or back without hitting the Shift Knob repeatedly ( palm of the hand ). The problem has gotten steadily worse as the weather has warmed up.



REMEDIES I HAVE TRIED ….



New shift knob ….. same issue.



Tried testing the wire harness, not my specialty.



Repeatedly drained my air tanks



If the transmission cools down or in the morning it seams to shift fine. I go up a 9% grade empty to get to work and it wont shift unless I pound on the shift knob.



Also if I am under a heavy load it seams to balk at shifting also.



Love my truck at this point if it keeps giving me bills I am ready to hang it up FOREVER.

 

Is that pounding, pushing the stick down? Maybe a worn shift tower causing an interlock problem?

 

Unknown

I think it might be electrical / heat issue myself.

 

When you hit the knob, is it while it’s in neutral? Could be the neutral switch. And after it starts can you get it to repeat itself while your parked?

 

Woohoo ! I found a cheap easy cure.

All you need for this is a phillips head screw driver, a piece of wire and electricians tool.

First take off the shrouding below the shift knob.

Locate the 4 pin wires.

Cut a 4 inch piece of wire off.

strip both ends about 3/4 of a inch. ( I used 18 gauge wire )

reduce the number of copper strands to 4 or 5 and twist together

push one end of the wire into and besides the orange wire going into the connector, push the other end next to the white wire going into the connector.

test your truck to see if it shifts into high and low range ..... if it does your done. electrical tape in place, button everything up and start rolling

if not i wish you the best of luck.

THIS IS A NEUTRAL SWITCH BYPASS. BE CAREFUL WHEN STARTING YOUR TRUCK AND MAKE SURE IT"S IN NEUTRAL !

 

You should know, that the neutral switch on that transmission tells the solenoid that transmission is in nuetral and it’s ok to shift from high to low or low to high. If your still in a gear and you flip the switch with it bypassed it will try to make the shift.

So be ready for the change in operation with the nuetral SAFETY switch bypassed!!!

 

What will happen if you run it this way? (Bypassed)

 

Meaning....Is it SAFE to run it BYPASSED?

 

As long as you are the only one driving, don't get tired and screw up, sure.
Make the money and fix it when you can.

 

Could you have not just replaced the neutral switch?