FML: AX15 Wont Go Into Gear

ty20404

Member
Joined
Feb 14, 2011
Location
Wilmington
The transmission has been fine for a while and just today it started to be tough going in and out of 5th gear. Then all of a sudden as it was being tough doing that it was a huge bitch to get it to go into any other gear 1st through 4th... Now as I was driving home (at midnight no less) I pulled it out of fifth and now it won't go into any gear.

I see multiple threads related to this on multiple forums but has anyone had this issue before? I know my throwout bearing was going bad and now when idling in neutral it makes a funny whirring noise (which I'm assuming is the throwout). Could it be just the throwout? Or is it a bad tranny?

All of this poor shifting happened in literally half a day, it was pretty much fine before that except the expected notciness of a 240k mile tranny.

That and recommended tranny shops in Mooresville or close by would be helpful, or if you have a sub 150k AX15 laying around. TIA.
 
What do you mean by bearing? I'm a mechanical engineer so I like the down-low on this sort of thing. Is there a specific name for it so I can figure out exactly why it's doing this?
 
you have your input shaft, output shaft, and counter gear shaft all meshed together with blocking rings and synchros. if the bearings supporting the shafts or one of them gets bad enough it will lose its effective mesh and wont allow a shift. put basically. try rev-matching.
 
I tried rev matching, still not possible. It won't even go into gear with the engine off.
 
Rev matching won't work if the mesh between the main and counter shaft is gone. There are 4 main ball bearings 2 in the front and 2 in the intermediate plate that hold the shafts on the correct alignment. There are also several spots with caged needle bearings that allow the input shaft to turn on the main shaft and allow different things to spin on different shafts.

My guess would be one or more of the ball bearings has deteriorated and is allowing too much shaft movement. If you try to shift it to hard you will damage the syncro rings. And if you drive it too much with the bad bearing you will damage the gears.
 
Mac5005 said:
Rev matching won't work if the mesh between the main and counter shaft is gone. There are 4 main ball bearings 2 in the front and 2 in the intermediate plate that hold the shafts on the correct alignment. There are also several spots with caged needle bearings that allow the input shaft to turn on the main shaft and allow different things to spin on different shafts.

My guess would be one or more of the ball bearings has deteriorated and is allowing too much shaft movement. If you try to shift it to hard you will damage the syncro rings. And if you drive it too much with the bad bearing you will damage the gears.
Click to expand...

Well I tried shifting it too hard and pretty sure that crapped the SOB out... Looks like I'm in the market for a used AX15.

Does anyone know of any mechanics in the Mooresville/Charlotte/Statesville area that they can recommend to do a transmission swap? It's something I'm capable of doing, but honestly, without a lift on the jeep, and a transmission jack it's just going to be a huge PITA to do. I have AAA w/ up to 100 miles of towing so if the shop is within that range (preferably closer) please let me know.
 
If you are in Raleigh,there is no better shop than TLC Transmissions.They are a Vender on the forum and you can't get a better rebuild at a better price anywhere.Here's a thread with some Happy Customers.
 
Just a thought and may wanna try... Check the slave cylinder... Mine went out and had the same symptoms. I may be wrong but lots cheaper than a trans.
 
mtmech said:
Just a thought and may wanna try... Check the slave cylinder... Mine went out and had the same symptoms. I may be wrong but lots cheaper than a trans.
Click to expand...


He never mentioned anything about having clutch pedal issues, but you are correct, if the slave went out, you'll have zero resistance on the pedal, and the transmission will not shift, unless the engine is off.
 
mtmech said:
Just a thought and may wanna try... Check the slave cylinder... Mine went out and had the same symptoms. I may be wrong but lots cheaper than a trans.
Click to expand...
Mac5005 said:
He never mentioned anything about having clutch pedal issues, but you are correct, if the slave went out, you'll have zero resistance on the pedal, and the transmission will not shift, unless the engine is off.
Click to expand...
Or along those lines, it could be a master that wont hold pressure internally.
 
When it happened to me... It was a bitch to put it in gear even with the engine off. Also there was pressure at the pedal just not at the slave... There was an enternal leak... It would build but not push the rod to the fork... Don't ask me how I figured this out lol
 
Well although I go to Raleigh every weekend I was kind of hoping to find somewhere within 100 miles so I could have AAA tow the Heep there. If I can find someone at work who's got space and is willing to remove it and let it sit then I may be able to take it to them. I'd honestly rather just swap out though as it will be cheaper than a $500 rebuild (which is cheap IIRC for a rebuild).

As for the master and slave, I don't have any leaking fluid anywhere and the slave/master setup looks quite new as if it were replaced recently. It more or less went out on me in a way that doesn't seem like a fluid system issue such as the master/slave. I guess the way to check would be by removing the slave then having someone (or a couple people) try to press the arm in to release the clutch and see if it will shift? If they can provide enough force...

I really think it's a synchro/bearing issue as the way it went out... 5th gear was notchy in and out, then difficult to go to 1st, 2nd, 3rd or 4th. Once it was back in one of the bottom four, the bottom four were easy. About the fifth time I went in and out of 5th it was impossible to go back to any other gear.

The only thing that gives me some hope that it's something else is the fact that my throwout bearing went from making the typical squeaky bearing noise when the clutch was engaged to making a whirring noise when the clutch was engaged, and the squeaky noise when disengaged? Can anyone shed some light on that? (PS I knew the bearing needed to be replaced but if that's the cause of this I did not expect it to get that bad that quick).

My roommate said it could prevent me from shifting if the bearing completely shit itself and seized to the input shaft....possibly?
 
Just had another thought.

It could be that the input shaft is starting to / is seized into the pilot bushing, this would cause the trans to act as if the slave has quit and making it feel like the clutch is not disengauging.

If it is, then the input shaft is turning no matter what you are doing with the clutch.

Would also comform to all the conditions you mentioned.
 
Mac5005 said:
Just had another thought.
It could be that the input shaft is starting to / is seized into the pilot bushing, this would cause the trans to act as if the slave has quit and making it feel like the clutch is not disengauging.
If it is, then the input shaft is turning no matter what you are doing with the clutch.
Would also comform to all the conditions you mentioned.
Click to expand...

I replaced the pilot bearing a month ago when I did the motor swap... I doubt that could be it?

I guess I should start by seeing if I can push the fork manually and see if I can get it in a gear... If I can then it's clearly a throwout bearing issue or master/slave issue. If not I'll have to drop the trans and see if I can shift it when it's by itself. If I can do that then its the pilot bearing I suppose. If that all fails then its got to be the trans.

Another thing that I noticed when I got the jeep is that to release the clutch I had to go ALL the way to the floor with the pedal. This could probably allude to a master/slave issue right? I suppose it may have been going bad (internal leak) then just crapped out on me.
 
I have personally rebuilt several AX-15's including the one in my jeep. The bearings for the output and counter shafter can get worn and will have play. The best repair for this situation is a minor rebuild of bearings. With a proper shop manual, and some GOOD snap ring pliers anyone can rebuild one.

Your situation sounds more like a clutch release problem, low hydraulic pressure, worn out clutch. Good luck man.
Todd
 
Mine would make a lot of noise when trying to get it in gear, but I could get it to change gears when the motor was not running. Mine tuned out to be a seized pilot bearing.
 
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