Allison Transmission not shifting forward?

[MrDough]

The Allison Transmission mated to my starboard Detroit Diesel 6v71TA no longer goes forward but can go to neutral and backwards. The shaft spins when going backwards but stands still going forward unless the boat is moving, in which case the movement of water spins it. I've checked the cable and it is pulling and pushing the lever on the tranny around the same as the port. Checked the oil too and it looks pretty new. I will check tomorrow by disconnecting the linkage to see if actuating it by hand makes a difference (cable not pushing enough?).

If moving the lever doesn't change anything, what could be the problem? Price estimates on repair are also welcomed. The transmission is pretty easily accessible but requires something to lift it out. Was pretty intense doing 360s to get back to port :smt101 (wind blew to the port side so it made it even worst running forward with only the port). Let me know, thanks

 

[stuckinforward]

these tranny's are pretty cut and dry, reverse plate for forward and one for reverse, the transmission you have utilizes the flywheel as a cylinder to apply the reverse clutch, so that to must be pulled and re-sealed. can you do a PSI check, if you have pressure in all ranges and the oil is nice and clean, then chences are something snapped such as the forward clutch hub or even the shaft. its hard to say but I buzzed thru alot of those tranny's in the 90's when they were more common. do you have anyone in your area that is familier with these transmissions? or the removal of these transmissions? you can call me tommorow to idscuss further if you would like 330-273-8291 or my call is 330-322-8817 eric

 

[MrDough]

Thanks. I'm going to check it out today and I'll give you a call if I can't figure it out

 

[MrDough]

SOLVED! Cable adjustment bracket backed out due to being too loose for some reason. Readjusted and tightened and added some more transmission oil solved the problem! :grin: No more 360s!