AOD, no 2-3 shift
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Senior User
Joined: Nov 2006
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AOD, no 2-3 shift
Hey guys,
I have a 90' E-150 van with an AOD that lost the 2-3 shift. I checked the direct pressure during a road test and found the it was coming up when third gear should have engaged. Thinking that the direct clutch was burnt, I planned an overhaul. During disasembly I found the larger orange nylon check ball had pushed out of the valve body and into the case. All the clutches seem to be in great shape but I replaced them anyway since I had it apart. A new converter with the fresh clean trans and a test drive still found no 2-3 shift! A direct clutch pressure reading this time found no pressure when there should be. Thinking maybe the 2-3 accumlator seals? The overhaul kit did not come with new seals for it so I reused it. Any thoughts? Thanks in advance for any help.
I have a 90' E-150 van with an AOD that lost the 2-3 shift. I checked the direct pressure during a road test and found the it was coming up when third gear should have engaged. Thinking that the direct clutch was burnt, I planned an overhaul. During disasembly I found the larger orange nylon check ball had pushed out of the valve body and into the case. All the clutches seem to be in great shape but I replaced them anyway since I had it apart. A new converter with the fresh clean trans and a test drive still found no 2-3 shift! A direct clutch pressure reading this time found no pressure when there should be. Thinking maybe the 2-3 accumlator seals? The overhaul kit did not come with new seals for it so I reused it. Any thoughts? Thanks in advance for any help.
Transmission Rebuilder
Joined: Jul 2008
Posts: 1,570
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From: North Georgia
With no pressure for the direct clutch I am thinking a stuck 2-3 shift valve, you should have pressure even if the seals are damaged on the accumulator piston, the piston would have to be missing to loose all the pressure.
I will certianly check that. Any idea what the larger check ball is for?
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Just a quick update, I finally got a chance to remove the valvebody. 2-3 valve appears to be fine. I will check all other valves as well. Air test plate to be here on tuesday. Will update agian at that point. Thanks,
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This just in, air tested the tranny tonight. Direct clutch checks fine, 2-3 accumlator leaks like a bloody sive!! Will not hold any pressure at all. I think there is an update for it to change to the later 4r70 accumlator? Rubber over steel? Anyone have any recomendations?
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This just in, replaced the 2-3 accumlator with a rubber over steel one. Checked the valve body agian, it seemed good. Put it all back together and test drive still finds no 2-3 shift!!!!! 1-2 is perfect with good timing, reverse works great also. Any other idea's? odering a new valve body today.
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