macattack Posted February 5, 2017 Share Posted February 5, 2017 hi guys. this is on a 96 mr 688s refuse truck. this is freaking me out. got a ht740 allison 4 speed automatic. has air mod valve and air operated throttle. past week my trans temp gauge and speedometer gauge were jumping around in unison. usually in neutral, but occasionally at road speeds. anyways last week my gauges acted up again and the truck lost reverse and if i put it in drive the truck dies. changed out the air mod valve, but still no reverse. a couple times it went into reverse, the reverse lites came on my back up alarm worked and then when i tried again in wont go into reverse and no lites or alarm.. gonna replace the tcm. i was told there is a solenoid pneumatic that maybe my problem any ideas. thanks Quote Link to comment Share on other sites More sharing options...
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