AX5 Trouble shooting

[mark99tj]

I have an 89 YJ, 2.5 with an AX5 tranny.

It does not want to shift into first or third gears. 2nd, 4th and 5th and reverse all work fine.

It will act like it goes in, but then pops out and grinds. I can get it to come closer to working in first then third. I do not know how long this has been going on, because I just picked the jeep up for my wife yesterday.

I have taken the shifter off. The ball on the shifter arm goes into a little cup. That cup is pitted and really worn. This is not the cup on transmission rail, but the cup that goes around the ball.

Some people have said that it may be the syncros, but in looking at the schematic, 1st and second share the same syncro, and 3rd, 4th and 5th share another. I don't understand tranmissions that well, but it does not make sense that 1st and third are out, on different syncros, and the other gears are fine.

Could someone either explain this to me, or suggest that there may be something else other than the syncros?

[mark99tj]

Does anybody know what it will take to put a TJ ax5 into a YJ? Would it require pretty much the same as swaping an AX15 in?

[STRAWBERRY]

Depends on the year of the YJ. A TJ has an external slave. Your 89 would be internal. I have a 90 AX-5 for sale. That would be internal slave also.

[Shadly1]

Depends on the year of the YJ. A TJ has an external slave. Your 89 would be internal. I have a 90 AX-5 for sale. That would be internal slave also.If the 89 is internal, the line at the slave can be disconnected. Wouldn't that screw right into an external TJ AX-5 since you're not dealing with that goofy 1-piece thingamabobber?

[mark99tj]

Ok, I got one, took the old one out, and now encountered a problem.

The old one had an internal slave on the clutch. The new one is external (with no slave currently). I am torn.... put the old bell housing on with the old slave, or just get a new slave, and leave it external.

Any experts available to give me help?

[Mechman71]

Go with the later setup. Get a new clutch kit for the later trans (disc, pressure plate, t/o bearing and pilot bearing) and a new external slave. If the external slave leaks it won't ruin your clutch.

[steeve555]

Use the TJ one w/a 94 or 95 slave/master combination. Use top bolt for the master on firewall and drill new botom bolt. Its best to get the slave master combination instead of trying to get the older master to work.

[mark99tj]

it's a YJ tranny (94 or 95) with the external, so I will not have to do any drilling. I was just torn because I wanted to wrap this up tomorrow morning so I could start to put this Jeep back together so my wife can park in the garage again.....

I am just going to throw the tranny in tomorrow and put it all back together and get the new slave on Monday now.

[Mechman71]

You need a later clutch kit if you're going to use the newer AX-5. The trans input shaft housing is different, as is the throwout bearing. The internal slave clutch assembly is for 87-92 internal slave trannies only. Put in a new t/o bearing while you have it apart - never trust used ones to be good. Make sure you check your flywheel for scoring and heat damage (radial cracks and/or discoloration on the friction surface). It may need to be resurfaced.

Your FLAPS should have what you need - call around, they are pretty competitive on prices. If your flywheel is decent, you can have it back together tomorrow night.

[steeve555]

You will still have to drill a hole in firewall for the mastercylinder. The external slave master has a different bolt patern. It's no big deal though. Inaddition go with the setup on clutch Mechman71 mentioned the input shaft on the newer set up is different. I think you need the fork from the later model also. Keep your old (or same type) Fly wheel. The newer one has triggers for the CPS which I am not sure it will work. Probably will I don't think your year has A CPS.

[mark99tj]

Ok, this just confused the heck out of me.

I took the 94 tranny, replaced the throwout bearing (used the existing fork, did not switch bell housings or anything), and bolted it up. the clutch and flywheel were fine (the engine was replace 40k miles ago, I have the receipt in the Jeep). I ordered the new master/slave kit. That will bolt into the bell housing. Drilling an extra hole in the firewall is not a big deal at all.

What did I miss? It all bolted up fine, but until I get the master/slave, i cannot test it.

[Mechman71]

It will bolt up fine, the splines from either clutch disc will slip onto the input shaft, but the pressure plates are different for the different slave setups. The clutch assembly for the internal slave tranny is for that tranny alone, specifically 87-92 transmissions. If you put in a later AX5 with an external slave, you have to install the matching clutch assembly or your clutch pedal will go halfway to the floor before starting to disengage, and will never fully disengage no matter how hard you push it. There isn't enough throw in the master and slave cylinders to move the throwout bearing that far.

Conversely, if you use a later clutch with an earlier tranny, the clutch will never fully engage because there will always be pressure on the pressure plate, because the internal slave cylinder cannot move far enough back to fully release the pressure plate.

You have to use the correct parts if you're going to upgrade, if you want it to work. Do a search for the clutch kits and you'll see that they have different part numbers for the different trannies. If you are using a 94 tranny, you have to use a clutch assembly that fits a 94. Luckily it will still bolt up to your flywheel.

[mark99tj]

Let me get this strait, I need a new clutch assembly? Not just a new master/slave?