Need some technical help

M

MileHiXJ

NAXJA Forum User
Location
Highlands Ranch, CO
I asked this over in the technical section, but I'm not getting too many responses. I have some time off today, and I would like to try to fix this problem if I can.

I'm having a little problems with my AX-15 transmission.

When I am idling in neutral at a stoplight, it is hard to get it to shift into 1st. I can usually put it in 3rd then go right into first no problem. But if I try to go directly into first, I have to force it in. There is no grinding, but I really have to strong arm it. And if the weather is warm, and the car is warm, it gets hard to put it into 3rd as well. 2nd gear is also hard to go into. If I am rolling to a stop, it slips right into 1st.

When I am moving, everything shifts very well.

The previous owner replaced the clutch less than 30,000 miles ago.

I have already flushed all of the the old clutch fluid out. I have gravity bled the system, and also bled it with the pedal. I have a vacuum bleeder, but haven't tried it yet. Flushing and bleeding it helped a little, but not

I've also changed out the transmission fluid. First I tried synthetic 10w30 oil, then changed it out with Pennzoil Synchromesh.

Do you think it is worth it to replace the master cylinder? I have an internal slave cylinder, so replacing it would require me to drop the transmission. Or is it the synchros going bad?

Any help would be appreciated.
 
Sounds to me like Syncros but it's hard to say. What type of oil are you running in it? If it's too thick an oil that can make it harder to shift, especially when it's cold. AX-15's require a certain oil from Chrysler but they don't sell it anymore. If I remember correctly the dealer now recommends just plain 10w30. The newer manual transmission fluids have certain chemical in them that don't necessarily work well with the bronze in the Syncros, so I've read.

That, or you just need to eat your wheaties in the morning. :D
 
Eating my wheaties, just trying to save the transmission.

I tried plain 10w30. Now I've gone to Pennzoil Synchromesh. Safe for bronze. I read loads of threads about not using GL5 tranmission fluids.

I just don't know what a bad synchro feels like. Flushing and bleeding the clutch fluid did help, but it didn't fix it. I'm hoping that I don't have to drop the transmission. Never done it. But I can always learn. I was thinking that changing out the clutch master cylinder may help, but I don't know.
 
Have you tried to double clutch before putting into first gear? That is fully releasing the clutch in neutral then re-depressing it before putting it into first gear.

I'm wondering if the PO resurfaced the flywheel instead of replacing it. Some say resurfacing is a no-no on the ax-15. Also, if he did resurface it, maybe he took off too much and now the clutch doesn't disengage fully.
 
Last edited:
UnlimitedMatt said:
if he did resurface it, maybe he took off too much and now the clutch doesn't disengage fully.
Click to expand...

THIS!
especially if its a concentric (internal) slave.
they make spacer shims u can put behind the slave to remedy the problem

bad synchros would grind a lot
 
On the S4 the 1-2 Syncro went out completely. No grinding, just very hard to get into 1st or 2nd.

Is it hard to go into first when the engine is off?

That is a good point on the flywheel, totally spaced that one. I guess that's what happens when you primarily work on diesels with automatics or if they do have a manual there are no Syncros.
 
I've tried double clutching, but it doesn't help. From what you all are saying, it's starting to sound like the flywheel. Not the news I wanted to hear, but it is a solution.

It is an internal slave. How hard a job is it to drop the transmission and add those spacers? But if I have to drop the transmission, shouldn't I just put a new flywheel on?

And to answer DutchVDub, with the engine off, it goes into all gears with no problem.
 
This sounds like a job a little harder than what I have done before. Is anybody available in the next few weeks to lend a hand, or can someone recommend a reasonable shop in the area that can do the work?
 
If you're going to do all of that then you might as well look into conerting over to an external slave cylinder. I've never done it before but here are several here who have. When the time comes I'd be willing to help out. I've got all the tools needed and dropping a trans on a little jeep ISA relative cake walk.
 
Thanks Dutch, I'd really appreciate the help. Just tell me when you are available. Maybe 10/1/11? I looked up the process of converting it to an external slave, and it looks like it could be pretty costly. It may be cheaper just to get another AX-15 with an external slave. Or I could just put in a new clutch kit, flywheel, and slave cylinder and call it even. Please get back with me when you can help me out. Thanks, Tom.
 
Too much machined off the flywheel results in grinding gears because the internals are still spinning.

If the trans feels like something is blocking the mechanicals when trying to shift up into 1st gear and no noise associated with it........ it's synchros.

How many miles are on this transmission? How much has it been used off-road/wheeling?

I'm thinking he'd be better off spending his money on a low-mile replacement trans.
 
Go ahead and vacuum bleed. I have had this same problem and they are a bitch to bleed.
 
If you're looking for a cheap alternative, I have an AX-15 with an external slave that shifts great. Only downside is that is has 190,000 on it. Syncro's feel good in it though.

Came out of a '97 Wrangler with mainly all highway miles.
 
What is the spline count on the output shaft on that?
 
23 spline
 
The clocking holes on the back is different than the XJ. So it'd have to be modified...but if you're looking for some parts for the conversion to and external slave, this would be a good option. :D
 
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