Allison MD-3060 Acting Up


LasVegasboyz

New Member
Question to all you Allison Gurus. I have a 1994 Allison MD3060 6-SP married to Cummins C8.3 in my motorhome. I am having some intermittent problems that are cold weather related. My transmission (during cold weather conditions after long stops - couple of weeks) shifts from 1st gear to 2nd gear, and then goes to error code 5622 (2nd Gear Range Verification test) and "Do Not Shift". Turn the motorhomme off, and turn it back on it comes up again. After doing it several times, it shifts to 3rd gear fine, but does not shift from 5th gear to 6th gear and gives error code 5655 (5th Gear Range Verification Test). Turn it on and off a couple of more times, and it is good to go. Last week I drove 600 miles with fine shifting after the initial 20 minute, 20 mile or so problems. The problem does not seem to happen when it is hot out (I am in Las Vegas).

Secondly, during cold weather (Las Vegas cold) when outside temperatures lows are in mid 30s and high in 50s (that is cold for Las Vegas), when I start the motorhome after sitting for some time (month or so), the transmission does not initially ingage (for about 5 minutes or so). I press the key pad "D" but no tone or transmission engagement. After about 5 minutes or so of idle time, the transmission finally shifts and I am good to go. The above Range Verification Test problem recently started, but the cold start-up issue has been there ever since I bought the motorhome in 2000. If I drive the motorhome weekly, it shifts fine at the start-up (no problems there).

Took it to the local Allison dealer, and they cannot duplicate the problem. Once I drive there, it gets to normal operating temps, and no problems (unless it sits for a while). They have pulled the codes and changed the output sensor. Very frustrating. Any ideas where to look for this. Or what can I tell Allison folks to look at.
 
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