AX15 Problems! New transmission time?

[EricT93]

91 XJ 4.0 AX15 4x4. PO converted to external slave cylinder.

Hey everybody. Since I bought my XJ, about 4 months ago, there has always been a slight shuttering when taking off in 1st, I just thought it was a Jeep thing. About a week ago it started grinding when down shifting into 3rd. Now the symptoms are, it doesn't want to go into second sometimes, grinds going into 4th, and other times it doesn't go into 4th at all. it grinds when downshifting into 3rd and when decellerating in 5th gear, if I shift it into neutral and coast to a stop, at about 5-10 MPH there's a small bang and shaking, like it finally popped out of gear. I swapped the fluid today and went with Mobil 1 10w30 but it didn't help, same symptoms. Thoughts? Would a rebuild be suitable or should I look for another used tranny? Thanks in advance!! Also, are there any direct swaps that might be more available?

[Mudderoy]

91 XJ 4.0 AX15 4x4. PO converted to external slave cylinder.

Hey everybody. Since I bought my XJ, about 4 months ago, there has always been a slight shuttering when taking off in 1st, I just thought it was a Jeep thing. About a week ago it started grinding when down shifting into 3rd. Now the symptoms are, it doesn't want to go into second sometimes, grinds going into 4th, and other times it doesn't go into 4th at all. it grinds when downshifting into 3rd and when decellerating in 5th gear, if I shift it into neutral and coast to a stop, at about 5-10 MPH there's a small bang and shaking, like it finally popped out of gear. I swapped the fluid today and went with Mobil 1 10w30 but it didn't help, same symptoms. Thoughts? Would a rebuild be suitable or should I look for another used tranny? Thanks in advance!! Also, are there any direct swaps that might be more available?

Hmmm I've never had a standard transmission Jeep until recently so I haven't had to go through these issues yet. However from past experience I remember breaking a synchronizer that cause a similar problem. The shuddering I would wonder if that wasn't a worn clutch and flywheel. I know that old 3 speed I had in my first car was very easy to work on, so I bet the AX-15 is as well.

[bigjim350]

It sounds like it could also be a weak slave cylinder. Like its not completely disengaging the clutch, making it difficult to shift. Or bad syncros. Either way it doesnt sound like you need a new trans, maybe just a freshening up. From your description it doesnt sound like anything is broken.

[nickyg]

Would a rebuild be suitable or should I look for another used tranny?
The inner workings of a transmission are a bit out of my wheelhouse but I can offer this bit of advice.
Years ago I owned a AMC Gremlin (I guess you can call it an ugly 2WD jeep or the first liberty)
The tranny blew out and not having a lot of cash on hand I got one from the junkyard. You guessed it. It was worst then the one I replaced.
My point being I would not put anything used in my jeep unless I have first hand knowledge of it's condition. of course body panels wheels etc.etc. are a good find at a JY. Sensors, engines etc etc, I'd stay away from.
I'm lazy and don't like doing things twice.

3602

[4.3LXJ]

The symptoms you describe, except the last one, are from two sources. First, you need a new clutch. That is what the shuddering is all about. Second, you may need a new master cylinder, or the new clutch may fix the rest too. The clutch is not disengaging completely and may have part of it out of adjustment or the master cylinder needs replacing to make the slave cylinder have full travel.

[EricT93]

The inner workings of a transmission are a bit out of my wheelhouse but I can offer this bit of advice.
Years ago I owned a AMC Gremlin (I guess you can call it an ugly 2WD jeep or the first liberty)
The tranny blew out and not having a lot of cash on hand I got one from the junkyard. You guessed it. It was worst then the one I replaced.
My point being I would not put anything used in my jeep unless I have first hand knowledge of it's condition. of course body panels wheels etc.etc. are a good find at a JY. Sensors, engines etc etc, I'd stay away from.
I'm lazy and don't like doing things twice.

3602
thanks bro

The symptoms you describe, except the last one, are from two sources. First, you need a new clutch. That is what the shuddering is all about. Second, you may need a new master cylinder, or the new clutch may fix the rest too. The clutch is not disengaging completely and may have part of it out of adjustment or the master cylinder needs replacing to make the slave cylinder have full travel.

Wouldnt a clutch problem be more consistant along each gear? the grinding is somewhat sporatic.

[4.3LXJ]

Wouldnt a clutch problem be more consistant along each gear? the grinding is somewhat sporatic.

The chattering is certainly a clutch problem. As far as grinding goes, maybe and maybe not. The clutch is not disengaging all the way and the synchros are not able to overcome it. At best, I would recommend replacing the master cylinder, which is cheapest and go from there. That won't fix the grinding problem, but it will tell you whether or not you have to replace the clutch to cure that.