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blevinsr 07-01-2012 09:12 PM

HELP my YJ won't shift into gear while on, but will when turned off.
YJ AX15 tranny worked before but it would grind while shifting into 2nd and 3rd. Dropped the tranny then had a shop rebuild it. The shop has excellent references and my buddies that use them have never gotten a tranny back that wasn't right. The shop did the rebuild as well as the put in a new slave cylinder. The shop said that the synchros were bad, and that at some point water had gotten into it.

Put the tranny back in and it will shift into all gears while off, with no problems. Start it up and it will not shift into any gear. Started it while in gear and it will move forward, or backward when in reverse.

Xpress 07-01-2012 09:14 PM

How much pressure is there on the clutch peddle?

Shadowkraze 07-01-2012 09:18 PM

You got clutch problems my friend.

ddtt225 07-01-2012 09:38 PM

sounds like the same thing to me shadow, but could it also be the syncronizer gear is possibly failing?

Shadowkraze 07-01-2012 09:50 PM


Originally Posted by ddtt225 (Post 2535577)
sounds like the same thing to me shadow, but could it also be the syncronizer gear is possibly failing?

eh, Not likely syncros in rev and 1st both go out at the same time, plus a supposedly reputable shop shouldn't screw up something as simple as a syncro imho with ax-15s. Sounds to me like the throwout isn't engaging the clutch. Could be installed wrong, pilot bearing not in, new slave cyl not having the air bled out or installed wrong... all clutch related

blevinsr 07-01-2012 10:04 PM

Clutch pedal has excellent pressure throughout entire length of throw. The synchros were just replaced. We bled the air out of the new slave. We're thinking the clutch as well but don't want to have to buy a clutch and drop the tranny again until we are sure.

Ant954 07-01-2012 10:10 PM

I had a similar problem when I did my clutch... Turns out I put the clutch plate in backwards. If I tried to shift while it was turned on it wouldn't go into gear and it would just grind.

sniffenjm 07-01-2012 10:46 PM

I had a similar problem after my ax15 rebuild . I did all work to save money. Somehow while putting it back together it didn't seat properly or shifted during rebuild and had to be taken apart again. Changed out the reverse synch again due to the same grinding as a safety measure and reinstalled. The shop owner had the same problem happen to his a few days prior.
While in reverse with clutch petal pressed it would try to roll forward weakly.

sniffenjm 07-01-2012 10:56 PM

I also assume since they did the rebuild and replaced the slave they also hopefully replace the throw out bearing. It would only make sense. Can you verify?

darkproximity 07-01-2012 11:42 PM

If the system is bled correctly then I'd also say your clutch disc was installed backwards, I had a shop install one incorrectly in my car years ago, let's just say the shifting wasn't easy especially in the higher RPMs, ended up destroying the pressure plate and sending one of the rivets through the side of my bellhousing into the gear box itself. This was before my mechanicing days, I do my own work now lol

blevinsr 07-02-2012 01:20 AM

I'll have to call him tomorrow to ask about the throw out bearing. My buddies have been using this guy for years so they are telling me there is no way he installed the clutch disk backwards.

blevinsr 07-02-2012 01:29 AM

Actually I was just told that the throw out bearing and the internal slave are one piece in the AX15, so if he replaced the slave he replaced the throw out.

darkproximity 07-02-2012 01:33 AM


Originally Posted by blevinsr
Actually I was just told that the throw out bearing and the internal slave are one piece in the AX15, so if he replaced the slave he replaced the throw out.

Not all ax15s, 94+ had external slave cylinder

blevinsr 07-02-2012 01:58 AM

Right, since mine was an internal slave then the throw out is connected to the slave. In an external it wouldn't be. Tomorrow night we are going to go ahead and replace the clutch, clutch plate, and flywheel. We were hoping someone had the same problem and a solution that didn't require dropping the tranny again. Doesn't sound like I can avoid it.

darkproximity 07-02-2012 02:05 AM

So did you install the clutch? Cuz your first post would lead me to believe that you did, and not the guy who rebuilt the transmission.

InvertChaos 07-02-2012 09:56 AM

Same thing happened to me last week in my TJ when my throw our bearing bit the dust.

Tyewilly 07-02-2012 12:16 PM

Before you pull it out, bleed, bleed, rebleed, and then bleed some more.
Oh, and btw, reverse has no syncro to those who mentioned it.

jj.91.yj 07-02-2012 12:55 PM

Mine is doing something like that I did all the work and had the fly wheel surfaced and the guy told me I did not need shims and now I can't shift unless the jeep is off

Ant954 07-02-2012 05:31 PM

Does it make a loud grinding noise when you try to shift when its on?'

blevinsr 07-03-2012 01:15 AM

Update: We took the tranny back out and found the pilot shaft (or input shaft) bearing had failed. The outer race is stuck in flywheel. Does anyone know if the throw out bearing/slave cylinder requires the pin/dowel? We bought a replacement clutch/clutch plate/throw out bearing and it came with a new pin, however, the existing throw out bearing (with was replaced last week) did not have the pin. If required could it have caused the bearing to fail?

blevinsr 07-03-2012 01:25 PM

Also, we didn't install the clutch because we couldn't get the bolts off nor could we torque them back on if we did. Once I convince the transmission shop that they caused this by leaving our that pin, I'm going to have them install the clutch as well.

Shadowkraze 07-03-2012 10:57 PM

Wait... so this reputable shop installed the clutch and transmission? You're telling me they didn't test drive it or have you verify it's in operation before you signed off on it. You got A LOT of trust in shops, I'll never have something done without verifying accuracy.

blevinsr 07-03-2012 11:58 PM

No a different shop replaced the clutch 4 months ago. I just finished dropping the tranny again and replaced the clutch, clutch plate, and the pilot bearing that failed. Started her up and she shifts better than ever.

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