As the title states, I am unable to shift my ax-15 out of neutral with the vehicle on. Seems to shift relatively decent with the engine off. I put the vehicle in reverse while off, pressed the clutch pedal all the way down, and started the engine and it lurched backward. Seems like the clutch isnt disengaging. Clutch pedal feels pretty normal for a manual vehicle, although I've only just purchased this jeep and have never driven it personally before. Just got the project back on wheels, tried rolling away, and ran into this shifting issue. Any pointers would be appreciated. I'm leaning towards a slave or master cylinder issue (hopefully), just wanted some others insight.
AX-15 wont leave neutral with engine running
- Thread starter Sensei
- Start date
It can be a multitude of issues.
But since you said the clutch pedal feels fine, I would speculate that its transmission side, the slave cylinder leaking, bent clutch fork, bad throwout bearing, or an actual clutch disc/plate misalignment could be the issue.
Easiest thing to check on the transmission side is the slave cylinder, should be on the driver side at the bell housing. Unbolt it and verify the piston isn't broken.
Other than that, its probably time to pull the trans and check everything else inside the bell housing, clutch disk alignment, and the clutch plate.
But since you said the clutch pedal feels fine, I would speculate that its transmission side, the slave cylinder leaking, bent clutch fork, bad throwout bearing, or an actual clutch disc/plate misalignment could be the issue.
Easiest thing to check on the transmission side is the slave cylinder, should be on the driver side at the bell housing. Unbolt it and verify the piston isn't broken.
Other than that, its probably time to pull the trans and check everything else inside the bell housing, clutch disk alignment, and the clutch plate.
How do I verify the piston is not broken besides obvious physical damage? I assume first thing I want to do once its out is check if depressing the clutch pedal actually causes the plunger to engage?
Jeep was sitting for 6-12 months before I got ahold of it. I really hope air got in the lines or something but even pumping the clutch pedal 20-30 times isnt yielding better results. Master cylinder was perfect fluid level. I really dont want to split the transmission from the engine :/
I'm fairly sure that's where your headed. It ain't too bad of a job. I'm betting your throw out bearing is trashed
Do you mean the throwout bearing? I'd probably be hearing some pretty devastating noises if the pilot bearing was seized, but the transmission sounds relatively fine. When I try to enter any gear, it doesn't grind or anything, but kind of stops me from entering the point of engagement. Reverse grinds though if I try the same thing. It almost feels similar to the reverse lockout in a way, but obviously that type of mechanism doesnt exist for the regular forward gears as far as Im aware
No, the pilot bearing. Sometimes the noise only happens when the bearing initially fails. After that you just have an input shaft that spins with the crank
https://www.freeasestudyguides.com/manual-transmission-pilot-bearing.html
no he said the pilot bearing. how many miles on this jeep ? it's probably due a clutch anyway. you say you have never driven it, so you don't really know what noises it was making before this started. pull the trans and replace the clutch assy. with a LUK kit I bet you find your problem there and if not it would have to be the slave cylinder, but I would doubt it's the slave cylinder.
Just got in contact with the PO. He tells me the transmission is a newer one directly from Novak. All Centerforce clutch parts, dual friction clutch, new flywheel, throwout bearing, pilot bearing, syncromesh fluid, etc. I'll probably replace the master and slave cylinder and post back with results. He also states everything was working perfect before he started taking the axles out for dana 60s, and then opted to move away from this platform in favor of something else, thus leaving this to sit.
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Under normal circumstances, if I were to depress the clutch pedal to the floor, would the fluid level in the master cylinder rise or fall? Or would it stay the same?
Technically it should fall as it actuates the slave cylinder, but its such a marginal amount in most cases that you wont see a change in level.
It's possible the clutch disk is stuck to the flywheel and/or pressure plate as well...
I don't think that's correct. Technically the master cylinder is already full of fluid. The OP is probably referring to the master cylinder reservoir which should not change during operation as fluid only drops out of the reservoir into the cylinder if there is a leak or if you are bleeding the slave. Pretty sure the level in the reservoir remains unchanged during operation, (however it will gradually rise as the clutch disc wears.)
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Yeah, thats why I said technically. Its such a small amount of fluid movement (atleast on my old MX5, you could see it drop about 1mm. Then again that vehicle held like 1qt of DOT3.)
This happened to me after a couple months of no driving. IIRC, I started in gear, got a few mph then slammed brakes. Someone else here please confirm the method?
I could shift when jeep was off, but not while engine was running.
I’ll second the clutch plate is stuck to the flywheel. Never thought about unsticking it by that method. Good idea.
If your Jeep was sitting in a moist climate this could be your problem.
If your Jeep was sitting in a moist climate this could be your problem.
Got the issue resolved! You guys were spot on, it seems like the clutch was seized to the flywheel. Even with new master and slave cylinder my issue persisted. I I let the jeep warm up for 20-30 minutes in neutral, turned it off, then did starts in 1st gear, got the jeep rolling good and started hard stalling it on purpose. After the 4th attempt it finally broke free and would idle instead of stalling (since I had clutch pedal down entire time). Clutch sounds super gritty now right at the biting point, but atleast my transmission works and I can shift through the gears completely normally now! Extremely excited, thank you for the help!
