MT-643RM Not Shifting

[Discreation]

Hi Everyone!

New to the community and appreciate any help.

I have a 1987 Bluebird All American(cat3208, Allison 643) that has been sitting for almost 8 months. I changed the oil, patched up some water leaks and got it running again.

The issue I'm having is before parking it we drove over 2000 miles with no transmission issues, but now that I've turned it back on, it seems to not want to shift into gear. When I put it into any gear I don't even feel it trying to go into gear. Also if I Rev it in gear it doesn't seem to push itself.

I've checked that the cable is working OK, not frozen. Is it possible that it won't shift due to transmission fluid sitting for so long? I can't tell if there's enough in there because I can't drive around, so I don't know if the fluid line isn't showing because there's no movement or because it really is too low.

Also I haven't moved it very far because of how it's parked, I don't want to roll it forward and not be able to roll it back. But if you think I just need to roll it a bit to get the gears moving I can try that too.

I'm new to most of this, so please let me know whatever info you need, or if my explanations need more substance. If be happy to clear things up

I don't have any light/electrical indications on my panel to tell me what gear it's in except for the actual shifter, assuming because it's all mechanical and older

[ewo1]

Originally Posted by Discreation

Hi Everyone!

New to the community and appreciate any help.

I have a 1987 Bluebird All American(cat3208, Allison 643) that has been sitting for almost 8 months. I changed the oil, patched up some water leaks and got it running again.

The issue I'm having is before parking it we drove over 2000 miles with no transmission issues, but now that I've turned it back on, it seems to not want to shift into gear. When I put it into any gear I don't even feel it trying to go into gear. Also if I Rev it in gear it doesn't seem to push itself.

I've checked that the cable is working OK, not frozen. Is it possible that it won't shift due to transmission fluid sitting for so long? I can't tell if there's enough in there because I can't drive around, so I don't know if the fluid line isn't showing because there's no movement or because it really is too low.

Also I haven't moved it very far because of how it's parked, I don't want to roll it forward and not be able to roll it back. But if you think I just need to roll it a bit to get the gears moving I can try that too.

I'm new to most of this, so please let me know whatever info you need, or if my explanations need more substance. If be happy to clear things up

I don't have any light/electrical indications on my panel to tell me what gear it's in except for the actual shifter, assuming because it's all mechanical and older

Allison MT 643 mechanic troubleshooting manual,
-link -> http://manuals.chudov.com/M939-Serie...anics-Tips.pdf

[cadillackid]

couple thigns to check.. start it up and while its running check the fluid.. if theres no fluid on the stick you are so low its not able pump, trans fluid levels go down when it cools.. so its possible you drove home and it was hot enough that it made pressure (and has a leak).. once it got cold the level may be so low that it cant make pressure..



if the stick (with engine running) is on full cold then try going into Reverse.. the reverse lights on this trans are pressure-activated.. if when you go into 'R' you dont get reverse lights or beeper (and you previously did).. it very well may mean you arent pumping pressure...



then its time to get a pressure gauge and fittings and hit the book the EW01 sent link to,..



if the fluid is not on the stick at all even with the bus turned off then its definitely too low to operate.. likely blew a seal or dripped out while it was parked..