Input bearing play and missing syncro key... time to rebuild AX15?

I recently bought a used AX15 off of craigslist (see last post) and have spent the last few days cleaning it up. This is my first time doing transmission work, so I've got a few questions:

1. If I pull on the input shaft, I can make the input bearing pop out of the case of the transmission by about 1/8". I can't do this on the old transmission that I pulled out of the car. Note that the front bearing retainer isn't on yet, so maybe that would eliminate the issue. Should this worry me though?


2. Today I was trying to clean out the dirt from inside the transmission. I kept filling it up with 10w30, spinning the shaft and shifting through gears, and draining. On one of the drains I found a syncro key had popped out. Is this a fatal issue that would require me to open the transmission and fix it, or can I drive with one of the keys missing from one of the syncros?


3. The transmission came to me with the little metal cover that goes on the front of the input bearing taken off. Do I need to try and put it back in place, or is it fine without? If so, how would I get it back on?


I can provide any more details that are needed-- thanks in advance for the help.

Well the front bearing retainer is supposed to hold that front bearing in. Yes, you going to need to open it up and put the synchro key/strut back in and verify that you don't have any others out of place. Did it fall out as a result of pulling the shaft forward?

lawsoncl said:

Well the front bearing retainer is supposed to hold that front bearing in. Yes, you going to need to open it up and put the synchro key/strut back in and verify that you don't have any others out of place. Did it fall out as a result of pulling the shaft forward?

Click to expand...

I’m not sure what caused it to fall out, but yesterday when I opened the transmission I saw two more at the bottom of the gear case. All three had broken and fallen out of the 3rd/4th synchro, allowing the front bearing to move.

Is there a way to replace the keys without removing the gearshafts and disassembling the internals of the transmission?


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I don't see how that would be possible .......

Between flipping through the FSM and my really vague memory, I think it's possible to pull the shaft forward enough without the bearing retainer in place that you could have caused the 3/4 synchro keys to slide out of place. Getting them back in without pulling the input shaft and reassembling the synchro set might be a challenge.


A full rebuild and replacing the synchros requires press gears on/off the shaft. I did mine with a modified gear puller and a lot of creativity, and hammer and cursing. Are you talking about a metal shield on the face of the input bearing itself? Shouldn't be needed as the bearing is bathed in oil.