Rogeroverout
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Please share your knowledge! This is a long one so I added the short version first. More information is in the longs story below. Thanks for your time.
I’ve got a 1083 A1 with an Allison MD 3070 and WTECIII keypad that won’t shift into Highway mode. Off road mode works as it should but just selecting D or R on the keypad won’t fully engage any gear. The CTIS is in Highway mode with a solid red light. C3 pressure switch just replaced, codes that were showing have been cleared and currently not showing any codes and the check transmission light is not on, 15w40 transmission oil is to the full mark hot idle in neutral. All connections appear to be in new condition
I am hoping this is something simple that I've overlooked. Please advise
Long story:
This truck has 2700 miles on the odometer and looks to be in great shape with very little signs of use anywhere. It came from the military and was adopted by a very small rural fire department. My goal is to get it to a serviceable condition so the fire department can turn it into a water tender while keeping the costs as low as possible. This truck was hauled to the location I picked it up after sitting for some time. Batteries were dead but were able to get it started after lots of individual charging. The truck started fine and seemed to run as normal for about 10 miles when the transmission disengaged showing 5 on the keypad. After shutting it down and restarting it operated normally for another 5 miles or so before disengaging again and wouldn’t move at all. After towing it home I pulled the following codes: 13255, 23233, 32511, 42544, 55666. Clearing the codes made no difference. Hoping the first code was the source of the other codes I replaced the C3 pressure switch which was determined to be faulty, (stuck open, would not close, and it bypassed all pressure thru the hole in the back). I also replaced the internal suction screen filter and internal wiring harness with new parts from Allison. There were a couple thimbles full of metal shavings in and around the suction screen area, no metal present anywhere else. I haven’t done any troubleshooting of the additional codes. After reassembly and refill with 15W40 the truck will not move when you push the D or R buttons in highway mode. (you can feel the transmission engage like it is going into gear but it feels like a slipping clutch that isn’t enough to actually go anywhere) If you press mode and the red light comes on the keypad, I believe that is Off Road Mode, then push D or R, it functions as is should showing a 5 on the keypad. You can even manually move it into first gear. I’ve been thru the TM’s and search the web with no luck on finding anyone with a solution to this issue. The keypad show no codes currently. I’m thinking it has to be something unique to the FMTV platform and hoping the expertise on this forum will have a simple solution. I know an Allison shop may be the best answer but again, I’d like to keep the costs down if at all possible and make sure it is not something simple before going that route.
Disclaimer: I am by no means a mechanic just a firefighter trying to get quality equipment into the field to keep fires small. The vast electronics on just the transmission of this truck baffle me! Thanks for reading
I’ve got a 1083 A1 with an Allison MD 3070 and WTECIII keypad that won’t shift into Highway mode. Off road mode works as it should but just selecting D or R on the keypad won’t fully engage any gear. The CTIS is in Highway mode with a solid red light. C3 pressure switch just replaced, codes that were showing have been cleared and currently not showing any codes and the check transmission light is not on, 15w40 transmission oil is to the full mark hot idle in neutral. All connections appear to be in new condition
I am hoping this is something simple that I've overlooked. Please advise
Long story:
This truck has 2700 miles on the odometer and looks to be in great shape with very little signs of use anywhere. It came from the military and was adopted by a very small rural fire department. My goal is to get it to a serviceable condition so the fire department can turn it into a water tender while keeping the costs as low as possible. This truck was hauled to the location I picked it up after sitting for some time. Batteries were dead but were able to get it started after lots of individual charging. The truck started fine and seemed to run as normal for about 10 miles when the transmission disengaged showing 5 on the keypad. After shutting it down and restarting it operated normally for another 5 miles or so before disengaging again and wouldn’t move at all. After towing it home I pulled the following codes: 13255, 23233, 32511, 42544, 55666. Clearing the codes made no difference. Hoping the first code was the source of the other codes I replaced the C3 pressure switch which was determined to be faulty, (stuck open, would not close, and it bypassed all pressure thru the hole in the back). I also replaced the internal suction screen filter and internal wiring harness with new parts from Allison. There were a couple thimbles full of metal shavings in and around the suction screen area, no metal present anywhere else. I haven’t done any troubleshooting of the additional codes. After reassembly and refill with 15W40 the truck will not move when you push the D or R buttons in highway mode. (you can feel the transmission engage like it is going into gear but it feels like a slipping clutch that isn’t enough to actually go anywhere) If you press mode and the red light comes on the keypad, I believe that is Off Road Mode, then push D or R, it functions as is should showing a 5 on the keypad. You can even manually move it into first gear. I’ve been thru the TM’s and search the web with no luck on finding anyone with a solution to this issue. The keypad show no codes currently. I’m thinking it has to be something unique to the FMTV platform and hoping the expertise on this forum will have a simple solution. I know an Allison shop may be the best answer but again, I’d like to keep the costs down if at all possible and make sure it is not something simple before going that route.
Disclaimer: I am by no means a mechanic just a firefighter trying to get quality equipment into the field to keep fires small. The vast electronics on just the transmission of this truck baffle me! Thanks for reading
