Can't shift while driving (except 3rd&5th)

1995 XJ, 4.0l, AX-15, 250k+

Trying to diagnose a transmission issue so I can get the Jeepie up and running for the snow time (little Miata ain't going anywhere fast in deep Omaha snow).

The symptoms are as follows: When the Jeep is running and at a full stop, you can only shift into 3rd or 5th. You can push with both arms and never get it into 1st (or 2nd) at a stop light. If you want to launch from 1st, you better down shift before you stop rolling. Otherwise you have to take off from 3rd, which is all kinds of fun in stop and go traffic...

While it is rolling you can get into all gears, but it almost seems like the clutch never disengages. 2nd is a clear "shift with no clutching" feel, involving rev matching, even with the clutch pedal fully depressed. 3rd and 5th seem to work fine, usually... Sometimes it doesn't like going into 5th at highway speeds, so overdrive is a maybe.

The pedal feel is good, not sloppy or any fading that I have noticed. No fluid seems to be leaking. If it is it is an imperceptible amount as I have not noticed any level drop since topping it off at the end of last winter.

The motor is tired and very leaky, but pulls strong. The clutch was supposedly replaced by the last owners around 190k, and when you can get it into gear it grabs hard.

Original thought was bad slave cylinder- with the thought it isn't disengaging the clutch all the way. Most symptoms I've read involve loosing fluid or bad pedal feel. I would rather not have to drop the tranny if I don't have to, but have already been gathering tools to do to so, as it will probably come to that.

Just looking for some community input as to possible diagnosis so I can make repairs as efficiently as possible. Any thoughts or suggestions are greatly appreciated. Thanks!

Has the clutch ever been replaced?

Does the Jeep "Pull" when you start it in gear but with the clutch depressed?

Pressure plates wear out, and I have seen pilot bearings seize.

Sounds like you have some work to do under the Jeep

-Ron

Quick test,push the clutch in with the engine at idel...wait 10 seconds,will it go into reverse without grinding?

WB9YZU- The PO claimed they replaced the clutch, but technically I have no proof. I've never had issues with it slipping that I could notice at least. It does not creep forward while cranking if the clutch is depressed.

Truckedup- I forgot to mention reverse. The answer is a definite no. To get out of parking spaces, I have to place in reverse, start Jeep with clutch depressed, back out, then turn the Jeep off, and put into first. It will not, for the love of any diety go into reverse, or first while the jeep is stationary and running. With the Jeep off it pounds through all gears with no touble.

Also to note it is temperature dependent. If it is cold out (20-40*) it actually does decent, I can roughly shift into all gears. Once the Jeep warms up though, it's a done deal. If the ambient temp is above 40ish, no go at all.

Sounds like I'll be pulling the tranny regardless. I've never dropped a transmission before, so I'm kinda nervous and trying to get as much info as I can. Thanks for the input!

Yup,your clutch isn't disengaging properly..Does a 95 have an outside slave cylinder? It may be the slave cylinder is acting up despite the clutch pedal feels normal. At least with the outside cylinder you can sorta check out the travel.....
If you need to pull the tranny/transfercase make sure you have a decent transmission jack and a helper with experience. Usually the difficult part is dealing with rusty stuff.Might need an oxy torch and a person who knows how to use it...Some like to pull the Tcase separate but rusty nuts on the tranny/t case studs makes it difficult while working under the vehicle.

Sticky pilot bearing.

The 95 does have an outside slave cylinder, so your first business is to check that the thing is operating correctly. If the master cylinder is worn out, it will not show, but may require pumping up the clutch before you get full disengagement. When doing the reverse crunch test mentioned above, try pumping the clutch pedal a few times, too. If it's better then, suspect a hydraulic problem.

Pre-97 clutch pedals have an extension arm welded to the top pivot, which engages the master cylinder. It is fairly common, though not always the case, that this arm will come loose or unwelded, and go crooked. When this happens, you don't get full clutch disengagment, and eventually it eats up the bore of the master cylinder, so check that that arm is straight, and the weld OK.

At the mileage given here, a clutch, even though its clutching surface may be fine, may be wearing out at the diaphragm springs. What happened on my 99 at about this point was that the thrust bearing, also wearing out, ate through the spring ends on the diaphragm, jammed and left me stranded. Sorry to say, there is no way to check for undue wear without taking it apart. My 95, at 262K, never quite quit, but when I took it apart (to steal its transmission owing to reverse damage on the 99 from trying to slam-shift it home through city traffic) I found that it was getting pretty close to failure, with a considerable wear spot on the diaphragm.

A couple of other notes: I've had clutch failures and had to crash my way home a couple of times, but the synchros on that AX15 are pretty much un-forceable until you're going at highway speeds. Not a good candidate for clutchless shifting.

I second the suggestion of a good transmission jack. This can be a bear of a job, but if the jack holds the transmission at the right angle, getting it in and out will turn out to be one of the easier parts of the job. Luckily I had an old transmission jack with iffy hydraulics, originally set up for VW rear engines, that could be pressed into service. I took more time getting all the drive shafts and the exhaust off than actually putting the box out and in. I took mine out the first time rather sloppily, but then took hours fabricating a rigid mount for the trans. jack using angle iron bolted together. It seemed like a poor economy until it came time to put the thing back together. I lined it up, and it popped in on the first try. Later, when doing the transmission swap, when I had to take two out and one back in, the time was abundantly worth it.

Also, before you start, get the correct inverse Torx socket for the upper bolts. In a pinch you can use other things, including welding the head of a seat belt bolt into a socket, but the right tool speeds things up!
edit to add: If you leave the transfer case on, the bolts that hold it to the crossmember are placed nicely for a transmission jack, and the assembly balances well.

fattmann said:

WB9YZU- Sounds like I'll be pulling the tranny regardless. I've never dropped a transmission before, so I'm kinda nervous and trying to get as much info as I can. Thanks for the input!

Click to expand...

Don't be too worried. Pulling a transmission really isn't that hard. In fact, I pulled mine out 3 times last year on a 1965 Cobra replica I built. Here are some things to think about:

1) unlike most automatics, a manual transmission bolts to a bellhousing which then bolts to the engine so the first step is to get the transmission out, next the bellhousing and then you will have access to the clutch.
2) I'm not sure how many bolts hold the transmission to the bell in a Jeep but expect at least 4 with the potential for 5 or 6. Since the transmission has to slide back far enough for the input shaft to clear the bellhousing, it is usually easiest if you can remove the shifter from the top before trying to slide the assembly back.
3) With the driveshafts and linkage disconnected, the oil pan on the engine propped with a box or some wood and the bolts removed from the transmission, you can set a hydraulic floor jack (aimed front to back so that it will roll) under the transmission and remove the transmission mount frame rail.
4) now, simply slide the jack back until input shaft clears the bellhousing. You can now lower the jack and drag it out or, push the whole assembly back and let it hang in the driveshaft tunnel while you work on the clutch.
5) Once you get the bellhousing off it should become obvious what the issue is. Before removing the pressure plate, mark it (and the flywheel) with a punch or some tape so you keep the balance aligned. Also, try to release the pressure plate bolts evenly (1 turn max per bolt) to keep it from warping.
6) Someone mentioned the pilot bearing and this is a distinct possiblity since it resides in the center of the flywheel and cradles the input shaft. If it is seizing, it will keep the input shaft spinning even when stopped so inspect it for wear. btw, some use a roller bearing design which is easy to check while some use a bronze bushing. These things can be a bear to get out but there is a trick on Youtube where a guy stuffs the center hole with grease, places a dowel (or a socket plugged up with wet paper) through the center hole while he whacks the end of the dowel (or socket) with a hammer. This approach essentially creates hydraulic pressure to push the bearing out from behind and works GREAT (I have done it a couple of times now).
7) last, go to the nearest autozone or O'Reilly's and buy yourself a clutch alignment tool. If the clutch plate isn't perfectly centered when you try to reinstall the transmission, you will fight with it for hours. These tools make it a snap to center the clutch plate and makes reinstallation a breeze.

HTH
Todd

A couple of additons to above:

Yes, you must take the shifter off. It's held in by a bayoneted plate, which you push down and then turn. Best if you get instructions on this, but it's pretty easy when done right.

If you get a new clutch, it may come with an alignment tool, so don't go right out and get one if you're replacing the clutch.

And on the Jeep the bellhousing bolts are removed and it comes out in one piece with the transmission
The guide dowels may be stuck requiring some work with a prybar to get the bellhousing to pull away.
The transfer case linkage can be a bit a bit difficult to deal with underneath
The u joint bolts may be rusted or have thread locker and may need heat to loosen.

Well I dun goof'd on that first post, I actually have a '92, for some reason I was thinking of my brother's 95 when I posted. So unfortunately I do not have an external slave.

Good points to look for Matthew. You can pump the clutch to you hearts content and it never changes anything. I'll have to check this pivot arm spot you mention. I will confirm the un-forceable comment, I've about thrown my arm out trying to force it, it's no use. There was a particulary hairy winter day that I had to put it in 4 low, launch in 3rd and get upto speed, then grind out of 4 low to get on the highway... It's been rough.

I have already drained the TC and tranny in prep for the drop. I planned on dropping the TC first seperately as I do not have transmission jack and didn't want to juggle the weight of both on our standard floor jack.

I picked up a set of those reverse star sockets, and am going to tackle this with my brother who helped his friend do a slave in an MJ. The part that concerns me is that while his shifting symptoms were similar, they weren't as severe, and he was loosing a lot of fluid.

By the way, adding to the shifter removal issue:

The FSM tells you to drop the whole assembly and work the bayoneted plate loose from beneath. This can be done. However, when doing mine I found it much easier in the long run to pull the console at the top, and to do it from above. It's way less finicky, you can see what you're doing, and the time saved on that part pays for the time taking the console out.

BAsically, if you don't already have a diagram, the shifter is held into the top of the transmission by a circular piece a couple of inches in diameter, which is bayoneted into the tower. You must push it down a bit, and then turn it, whereupon the entire shifter pops out with that piece attached. It's relatively easy to get apart, less easy to put back together blind, because it is spring loaded, and greasy.