i have a 89 international school bus with a allson auto in it it sat for 3 yrs after a lot of messing around i got it running it will only shift into first gear and reverse only will not shift up i have to the 12 to fix this thing anny info would help a trans shop said ck the govner if it looks like an apple core it is the prob anny idea i have no knowalage on the allison auto

the govoner gear is broken,or i should say the plastic shaft. if its a 540 or similar 545 on the left side is a cover towards rear .pullit off and pull the gear and shaft out.you probably won t get the little end out.I usually cant.get a new govoner shaft (used to be around 15.00 ) and lube it up and put it back together.the little end will fall into pan(never had one hurt anything down there). should shift into other gears now. hope this helps if you haven t already fixed it.

sorry ,it could just be the governor is hung up,its like wings they should flip out when the trans is spinningjust make shure the flaps move free. dip in tranny fluid and move them back and forth they should work.But if the unit has been driven i will bet the shaft is broken off. its about the diameter of a pencil. just wanted to add this.