View Full Version : ax15 problems

06-14-2009, 05:24 PM
so i've been helping a friend of mine do a 2.5 to 4.0 ho conversion on his '94 yj and we're running into some transmission problems.

the motor/transmission/t-case all came out of a donor '92 yj but we figure that it might have been a '94 or something due to the external slave.

after getting everything together everything was fine until it came time to drive it. 2nd gear required double clutching and 5th needed to be forced. the transmission lasted a week before 5th no longer worked and the transmission was full of shavings.

so my buddy went to gary's and picked up an ax15 from a '98 cherokee. the '98 cherokee had a different tail shaft housing so we switched that out between the bad one and the newer one.

got everything together again and 2nd gear still needs to be double clutched and it's impossible to get the transmission into 5th wether it's running or not.

we thought that we might have confused the shifters between the ax5 that was originally in there and the ax15 but we have come to the conclusion that it's impossible.

wtf are we doing wrong? the jeep has a fresh 2 1/2" bds lift kit with transfer case drop bolts but i can't see how that could affect anything. the shift boots are not in the way. there is plenty of clearance between the shifter and the floor. the clutch engages and disengages properly.

all i can come up with is that this transmission is screwed too.

06-15-2009, 11:20 PM
Sounds like 2 bad transmissions to me. 2nd gear goes because it has heavy load/high torque on the synchros, not sure about 5th. If the clutch wasn't disengaging completely, it would be hard to put into 1st and reverse standing at a stop. Does it grind when you put it into gear or feel resistance?

Those trans are really easy to overhaul, the front and rear cases seperate from the centre section and the shafts stay attached to the centre section. Check the gears (where the synchros engage) and the shift forks carefully.

06-16-2009, 12:02 AM
we actually figured it out today. when we pulled the tail shaft housing off of the transmissions a ball dropped out and we couldn't figure out exactly where it came from and didn't have access to diagrams at the time. the ball is known as the "lock ball" and is supposed to go behind the lock ball spring which is held in with the lock ball plug/bolt which all gets installed and removed before removing the tail shaft housing. we didn't do that.

we originally put the ball at the end of a shaft because there was a divot in the end of it. this stopped it from going into 5th.

the second gear thing was a lubrication problem. after soaking overnight it worked itself out.

06-16-2009, 12:30 AM
hrmmm good info to know in case i run into the same problems, glad you got it all figured/worked out,

06-16-2009, 12:41 AM
just remember that there is a torx head bolt, spring and ball that need to be removed before removing the tailshaft housing. the ax15 manual says you need a "pencil magnet" to remove the spring and the ball.