6 speed dying?
 

I got a clutch/trans-related head scratcher for you folks.

If I'm in neutral and let the clutch out, there's enough engagement to almost kill it and creep fwd.
At highway speeds it shifts into 5th and 6th easier if I don't use any clutch at all.
When I use the clutch while shifting up 2nd-4th I need only depress the clutch maybe half an inch
but if I press it in all the way I'm completely locked out of these gears.

- 6 speed
- Super miata 4 puck sprung clutch
- Amsoil synchotech

Im a good long ways off of trans killing power levels.
~14# on a 2860, virtual dyno said something like 260

Clutch and fluid only 1 season old.

I replaced the master/slave a few days ago due to hard/rough shifting.
I did adjust the pedal at that time. It cleaned up the shifting feel but not entirely.

It was shifting pretty well Saturday morning before a track day. No crazy instances during the track day.
Most of the laps were spent doing lead/follow instructing.

Im going to replace the trans fluid with amsoil gl4, rebleed the clutch line and reconfigure the pedal engagement but I'm just worried the trans is on its way out.

Failing those steps, I intend to pull the trans and get a look at the fork and clutchface/springs.

Here's a thread similar to your situation. I believe the issue is technically repairable but in general a replacement 6 speed is the answer.

https://www.miataturbo.net/suspensio...d-diff-100587/

I agree. The two piece gears are likely the issue from what I know thus far of the two 6 speeds I have, early and late.

Curious what the VIN number on that trans is, or if you know what year car it's out of.

The trans should be original to the car, which is a 2002 SE.

Have you tried pressing them back together and tack welding them? I dug into the above link and apparently, thats an option.

Also, I see youre in Wisconsin. Seen any 6 speeds for sale recently? Im afraid Im going to have to cancel my registration for Track Day Picnic if I cant get this resolved.

So 2002 SE is on the late side of the shifter change cutoff, I was curious if that correlated with the internal gear change and that doesn't seem to be the case.

I ended up buying a second 6 speed which happened to be out of a late car, but what I don't know if it still has the two piece gears or welded from the factory.

On the first one, we we did press the gears back in easily but haven't welded yet. The longer term plan is to weld, reassemble, and keep it as a spare just in case what I have in the car now doesn't pan out or hold up.

I had a hell of a time trying to source one. Bought one from Redline, then they said "just kidding, it was a 5 speed". Couldn't find one local. Ended up ordering from LKQ Online, and it worked out OK without knowing the health of the internals, anyway. They did ship fast and the price wasn't terribly out of line. I'm also in a time crunch since I already missed our first local autox and still need my car tuned after the motor build.

Good luck!

Thanks for the info, ooc, do you recall what you paid LKQ for the spare?

Sure, about $850 shipped for one w/ 100k on it, from a southern car.

For some odd reason LKQ only shows the 5 sp as an option. Even when choosing 2005 as the destination car. Womp.

I'm seeing tell that the rx8 6sp trans internals are identical to the miata 6sp trans internals...

Has this ever been confirmed? I've only been able to find mention of it.

bump

Bump

I have a conspiracy theory level thought process that this meant to be kept a secret at this point :ughug:

There are things that are not a perfect match. BBundy has taken apart a ton of 6 speeds to mess around with. What you are thinking about doing, more then likely won't work.

Shit

Ive messaged BBondy to no avail.

One last bump. Im considering just buying an rx8 trans for cheap and going to town with the intent to learn.

I disassembled a RX8 gearbox last winter. Most of the parts are slightly different and not much can be interchanged in a Miata 6 speed.

Oh... shoot. For this purpose?

Ive recently purchased the Rx8 trans but havent gotten around to disassembly yet.
The daily audi needed a rear main seal replaced -_-


The center housings are identical from the outside. The bell housing will bolt up to the rx8 center.
Its just a matter of tail housing/components.
The plan was to start at the tails and swap things over until the miata tail housing bolted up.

Let me know what all you found in more detail if you come back to this/feel like it.

Thanks!