Put an AX15 in my '88, now I have no clutch. Halp!

Hey,

I just got done putting an AX15 in my MJ. The motor is an '89, the transmission I think is from a '92. The clutch kit that O'Reilly's had listed for the '92 did not include the internal slave cylinder so I went with a kit for a '91. I used the '70s CJ pilot bushing. I gravity bleed the slave cylinder, start the truck up.. And nothing. Won't move. The transfer case is in gear. I can run through the gears with the engine running and my foot off the clutch and nothing. Before I installed the transmission, I did play around with it, by turning the input shaft in different gears, and everything seemed kosher so I'm pretty sure something is up with the clutch assembly. The clutch pedal did feel kinda spongy and sticky at the same time. Could something be plugging up and not letting the slave cylinder retract? Could it be catching on something? Defective pressure plate perhaps?

Anyone have any ideas? We're supposed to get a monster snow storm in 2 days and my other vehicle is on bald summer tires so I would kinda like to get this figured out.

Unfortunately with it being an internal slave I think you're gonna end up dropping the tranny to troubleshoot this. It could be a sticky slave cylinder, it could be a thin clutch disc (probably not), it could be a defective pressure plate.

Now that I think about it... when you bolted the pressure plate onto the flywheel, did the bolts end up compressing the pressure plate as usual or did it not take any pressure to get the pressure plate ears seated on the flywheel? Did it feel like the "normal" amount of pressure?

(I think I may have tried to answer this on another forum...)

Hmm, nothing struck me as out of the ordinary when I bolted up the pressure plate. I'm 99% sure I remember compressing the pressure plate as normal. And the disc stayed in place once I removed the alignment tool; I had no trouble stabbing the transmission. I don't even get a little crunch putting it into reverse without the clutch which leads me to believe that the slave is holding it completely disengaged. I'll probably try getting really mad at the clutch pedal tonight then drop the transmission first thing tomorrow.

Yes you did, and I thank you again.

Hmm, messing with the clutch pedal a bunch and bleeding it a ton seems to have fixed it. Looks like I'll have transportation during this snow storm after all. I really oughta drop the transmission anyways to see what's what, but I'll probably just ignore it till it leaves me stranded.

Gravity bleeding can help, but I prefer vacuum bleeding or pressure bleeding - both techniques are more thorough (and vacuum bleeding equipment is common.)

You do need a helper with vacuum bleeding, but you'd need one to do gravity bleeding properly anyhow.

Admittedly, my first thought when reading this was that you'd used a later "external slave" clutch kit on an internal slave transmission - a common enough error that I've a boilerplate response to it somewhere...

Glad you got it sorted - but you may find it useful, in future, to invest in a vacuum bleed kit. They are not costly, even if it's a "full" kit - hand vacuum pump and all. Considering the time & effort it can save you, well worth the cost...