So this AZ6 was rebuilt by the PO I bought it from. It was a little notchy since day 1 but always shifted fine. After a while, it became notchy enough left to right that the shifter didn't have enough spring rate to center itself. It eventually developed an issue where it'd get locked out of 5th and 6th for a minute or two after doing a pull above 6k rpm in 6th gear. I drained the fluid and it came out a real nice silver color. Metal all over. Also, I never thought about it until recently, but it'd spin the wheels at a couple miles per hour in neutral if I had the car running in a lift. More details in this thread but that's basically the gist of it. https://www.miataturbo.net/suspensio...rarily-108971/

I started tearing down the trans and found what I think is the countershaft shift fork bushing... missing? Can anyone smarter than me confirm that there should be something taking up the dead space between the shift rod and the fork itself? Seems like that'd cause the issues I had with this thing.

I also found the small circlip on the countershaft behind the front trans housing plate dislodged and floating around. Although, I don't think this was causing my issue.



Thanks in advance to anyone who has input/insight.
-Zak

 

I’m not smarter than you, so I shouldn’t be replying, but yes, tires rotating in neutral on the lift is normal. My same question awhile back:

https://www.miataturbo.net/suspensio...eutral-101777/

Since you have the transmission open, check out Herring Racing’s videos about 6-speeds. Might be obvious, but they were worth a reminder or two.

 

I’m fairly certain there’s supposed to be a bushing there, yes. And yes, most manuals rotate wheels in neutral.

 

Don’t be so sure.

Thanks for the heads up! Don’t know how I’ve never come across those videos before with all of the searching I’ve been doing. I don’t think I’ve ever heard about someone welding anything together inside one.

Thanks for helping to confirm. Couldn’t imagine there was supposed to be a void in that empty space. I can swear my five speed didn’t spin the wheels in neutral on the lift but then again I never really checked closely.

 

There is definitely supposed to be a brass/bronze bushing and the fork should not wiggle around like that, it should be pretty tight.
Ping me if you need parts, i tore down a 'sploded MSM trans last summer and its all in a bucket.

 

I’ll be PM’ing you later this week or weekend, sir. I’ll take that bushing and the countershaft circlip that popped out in mine. Gonna take a deeper look and see if anything else needs replacing as well.