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98 XJ Ax-15 Problems

NchsaXJ

NAXJA Forum User
Location
north carolina
I have a 98 XJ 4.0 Ax-15 and ive had an issue with the shifting for over a year now and ive searched alot on the web for a similar problem like im having but i havent been able to find anything similar yet. Ill try to explain as much as possible about my jeep. I bought it dec. 2015 and it has 280k on it now. Runs well for that many miles too but its no spring chicken for sure. The P.O. had it since 60k and drove it till 260k. Ive put about 20k on it so far and ever since ive owned it ive had a problem shifting after the jeep is warmed up and mainly when ive been idling for a while or wheeling, ultimatly its only noticable when the jeep isnt moving much or very fast. Its the worst in 1st and reverse but it does in fact begin to happen to the other 4 gears. It will get to the point where im on a trail and i cant get it into 1st from neutral to save my life. I have to turn the jeep off and then it slides right into 1st or any gear butter smooth. When i start the jeep in gear after that its like the clutch is still sticking and i can feel the jeep roll ever so slightly. It doesnt start as easily at those times either because of that too. I havent abused the clutch since ive had the jeep and the clutch was replaced and flywheel resurfaced not long before i bought the jeep too. The P.O. did say his son was starting to drive and couldnt drive a manual very good so it leads me to wonder if he put excessive wear on that new clutch before i bought the jeep. I have replaced the master/slave cylinder for the clutch and it may have helped a bit but it really disnt change anything about the shifting once the jeep is warm. If anyone has any advice or has had a similar problem with their ax-15 i would greatly appreciate the response so i can get this figured out. Its a spare vehicle/project so its not a urgent issue but i do enjoy driving it alot. It isnt much fun the way its been running though. Thanks, Jake.
 
What fluid are you using?
 
By what your describing it sounds like the clutch is dragging. Give bleeding the clutch a go and bleed some new fluid in. Just fought that with my buddy's s10. Put a used trans in with a new clutch and it can't grab 2nd sometimes and needs the clutch bled.


Sent from my iPhone using Tapatalk
 
By what your describing it sounds like the clutch is dragging. Give bleeding the clutch a go and bleed some new fluid in. Just fought that with my buddy's s10. Put a used trans in with a new clutch and it can't grab 2nd sometimes and needs the clutch bled.
I bought a new master/ slave cylinder for the clutch and it came pre-bled and sealed. I think it said not to do that on the package. Like i said i put a brand new one in and nothing really changed.


Sent from my iPhone using Tapatalk
 
MT-90 or MTL and you can get a LUK clutch for not a whole lot on rockauto. When I replaced my engine I put in a new LUK clutch and flywheel.
And get the redline on amazon, its usually cheaper. (and prime shipping)
 
either one is fine.

At this point i would drain out whatevers in there, and start with fresh redline mtr or mt-90.
Mine had syncro issues fromn the PO outting gear oil in there. , no more problems after the MTR.


Do yourself a favor, and fill it through the shift tower.
 
either one is fine.

At this point i would drain out whatevers in there, and start with fresh redline mtr or mt-90.
Mine had syncro issues fromn the PO outting gear oil in there. , no more problems after the MTR.


Do yourself a favor, and fill it through the shift tower.

Do i just take the 2 rubber boots off to fill it through there or is there more i have to take apart?
 
IF you can easily get it in gear with the engine off, it's likely the clutch is worn out. Diaphragm clutches, as they age, will see the pedal lose "range". What I mean is that the distance the pedal moves between engagement and disengagement will get smaller. Eventually, the distance becomes zero, and the clutch won't disengage. The lining isn't necessarily all gone, but the diaphragm (spring) has weakened to the point of not being able to disengage the clutch. Since you've already bled the system, you've eliminated that as a potential problem, which can cause the same symptoms.

Luk clutches are probably the best solution for the money. I have a kevlar clutch, but that's probably overkill.

I also use Pennzoil Syncho fluid. You can also buy a fluid pump for a under $10, and use that to fill through the filler plug.

David Bricker / SYR - TUS
 
IF you can easily get it in gear with the engine off, it's likely the clutch is worn out. Diaphragm clutches, as they age, will see the pedal lose "range". What I mean is that the distance the pedal moves between engagement and disengagement will get smaller. Eventually, the distance becomes zero, and the clutch won't disengage. The lining isn't necessarily all gone, but the diaphragm (spring) has weakened to the point of not being able to disengage the clutch. Since you've already bled the system, you've eliminated that as a potential problem, which can cause the same symptoms.

Luk clutches are probably the best solution for the money. I have a kevlar clutch, but that's probably overkill.

I also use Pennzoil Syncho fluid. You can also buy a fluid pump for a under $10, and use that to fill through the filler plug.

David Bricker / SYR - TUS

Thanks a ton for that info. That distance is indeed small now between where it engages and disengages and it having the 3.07 gears and 30s makes it alot harder on the clutch im sure so that makes sense that the clutch is probably about shot now. Will i need to resurface the flywheel or buy a new one along with the new clutch?
 
You replaced the master and slave, with what? aftermarket?

Your problem is hydraulic, not the clutch itself.
As the clutch disc becomes thinner/smaller your engagement/disengagement becomes greater, not lesser.

You cannot bleed a Mopar hydraulic slave, no bleeder.

Aftermarkets suck, hence, your problem.
 
You replaced the master and slave, with what? aftermarket?

Your problem is hydraulic, not the clutch itself.
As the clutch disc becomes thinner/smaller your engagement/disengagement becomes greater, not lesser.

You cannot bleed a Mopar hydraulic slave, no bleeder.

Aftermarkets suck, hence, your problem.

Yeah it is aftermarket. Its a little harder to press than the old one but it isnt a huge difference. I was thinking about when i installed it and youre right, there was no place to bleed it. It was i think the cheapest one on rockauto and i think the brand i got was discontinued if im not mistaken or something like that.
 
If your jeep is still together and drivable you can try to pump the clutch pedal quickly 6, maybe more, times then try to feed the gear select into 1st. If pumping makes the gear selection easier that is a good indicator of a faulty hydraulic system.
 
there is a way to get air out of the system, you just gotta essentially use the master as the bleeder. pretty sure there is a vid or two on youtube of how that works
 
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