6 speed woes
 

preface: i have never done transmission work before, but i did my homework before cracking into it
story: picked up a cheap 6 speed. 5th and reverse would not engage. Was planning on opening it up, so diagnostically removed the donotremove pivot bolt, (bolt took a few horsetorques to remove) Clunk. Can confirm was not the issue.
Yank the bell housing off and fight with bolt for a while. After one beer, i clean off the threads and make sure the bolt goes through them butter smooth and that the bolt goes through the lever. After beer #2, i got it lined up but the bolt wasnt happy about going into its home. Pull it out and now the bolt wont go into the hole, even after some mild machining with a file. Ive given up for the night but crave input.

1) does anybody have spare of these items from a grenaded 6 speed?
2) what would have caused 5th/r to not engage before donotremove was removed initially? I heard it fall when i pulled it for sure.
3) am i barking up the wrong tree; could my problem be elsewhere in the trans?

1. I have parts from 2-3 different transmissions I took apart last year. Shoot me a PM with the pictures of what you need and I'll pull them.
2. I had a similar issue. I had a trans that wouldn't engage reverse. I found that there are bushings in the shift forks that can work themselves out. In my case it had work its way out and wouldn't allow the shift fork to move enough to engage the gears. I'll have to check if I have one of these to spare. We had to check a few to make sure they were in good shape when I did my rebuild.
3. Look very closely at your 5-R shift fork, I bet that's the issue.

I just finished rebuilding my AZ6 over the weekend. I hope you downloaded the service manual.

Can you engage all other gears except 5th and reverse? You should be able to row the shifter and spin the input shaft by hand. That would immediately narrow it down to the clutch hub or shift fork if all other gears work.
The 5th / Rev clutch hub is unique because 5th gear is on the input shaft and the clutch hub and reverse gear are on the main shaft. I could see a situation where the clearance opens up between the input and main shaft and you overstroke the clutch slider trying to engage 5th, which would cause the synchro keys/ball bearings/springs to fall out or even just bend the springs and jam the slider on the clutch hub.

Prior to surgery, all other gears functioned properly except 5/R. It felt like hitting a wall and refused to engage.

To my untrained eye, nothing in the gearbox looked amiss or out of place. I filed the bolt and pivot until the bolt went in and out smoothly, then greased it up before replacing the bell housing and now it goes into every gear properly.
My theory is simply that the bolt and pivot seized together. Ill report back (hopefully this weekend) when I have the shifter rebuilt and the trans in the car.
As it sits on the bench, it goes into every gear and feels like it should though.

Update + closure

Trans went into all gears on the bench. Installed it today. All gears function normally. Shifter still needs rebuilt though. I notice that Moss has two different kits for 6 speeds, how do i know which one is right for my trans? Theres no visible VIN on it if that matters.

Mid year change in 2001. The size of the ball at the end of the shifter determines it

Bringing this thread back.

6 speed still works good but has some caveats to it now.
Gear whine in 1-2 when cold, makes audible noise shifting 1-2, misses 6th at moderate load and has a vague R.

Didn't miss 6th before I swapped to the bronze shift bushing though, so I think drivetrain twist might be to blame but I never miss it at high load so I'm unsure. Colder temps attribute to shift noise and gear whine as they usually go away when warm, noticed this in spring when i put the trans in and it went away when it was 90+ degrees in summer.
Side note: the bronze bushing from my 5 speed fit the 6 speed lever, so that was neat

However, I seek guidance on reverse. My original 5 speed had a similar issue where sometimes it feels like it goes into reverse, but makes a whirring noise when i let off the clutch pedal. Taking it out of gear, pumping the clutch a couple times then going for it again works, but I seek similar experiences and hopefully solutions.
Or maybe my theories on other problems are wrong and someone has room to correct me.

I haven't experienced an AZ6 with a smooth operating reverse gear. The BRZ with an updated AZ6 still has complaints about engaging reverse.

Mine was extremely difficult to engage before I rebuilt it. Same problem you have; just extremely difficult to engage.
When I pulled it apart last winter the reverse syncho was completely dead. No braking action at all; it bottomed out on the face of the gear and didn't even contact the cone. I replaced the syncho, 5th/Rev clutch sleeve, and 5th/Rev shift fork. I also used some green scotchbite on the gear cone to break the glaze from the old syncho and the new syncho engaged well and clearance to the gear face was in spec. I got that tip from watching the GearBoxVideo youtube channel, while building up confidence to tackle the rebuild.
Everything spec'd out per the manual, other than the syncho, but I threw some parts at it since it didn't work well. It definitely works much better than before, like I can actually engage reverse 9 out of 10 tries, but in the spectrum of manual transmissions still sucks. Previously it took at least 2-3 attempts with some clutch kicking and shifter stirring to get her in.