7 replies to this topic

[JamesDianto]

Hello all. Need some advice or guidance. Original 5 spd transmission on my 95 NA8 "lost" 5th gear. What I mean by "lost" is I couldn't physically get the shifter past the gate to put it into 5th, it just wouldn't move into position. Funny enough, reverse was OK. This happened with engine off, engine on (idle) and on the track (not the going into reverse part!). All other gears work just fine (and yes, I know I don't need 5th gear but I don't want to buzz the engine too high when I'm only doing lap days at ECR). 

 

I figured the synchro or gear finally gave up the ghost and I had to install a dfuser 3-pad puck I thought was already in the clutch anyway, so I swapped it with another transmission from a 99 while I was there. Still experiencing the same problem, only now it's worse! I can't get it past the gate into 5th OR Reverse! Again, what I mean is I can't get the stoopid shifter to the right to even think about 5th or reverse. It's like it's hitting a brick wall no matter how hard I try without breaking something. 

 

I'm taking the original transmission apart just for grins to check linkages, 5th's synchros and gears. I took all the parts off the shifter linkage and inspected everything and it all looks fine, I can move the box manually. I did this on the swapped transmission as well before I put it in and I could move the linkage and engage the gears (not easily since I didn't have the leverage but it worked). 

 

One interesting note: before I installed the three shifter turrent bolts holding the shifter down, I swear I was able to get into 5th and reverse, when bolted down onto the box (not tight at all) I couldn't. 

 

So I'm posting to see if anyone else has encountered this issue. I did some searches in the interweb but no concrete answers. When I figure it out I'm going to post it everyone so people can find it. 

 

I'm going to start with the easy stuff: reexamine the linkage, rebuild the shifter (I did it a couple years ago w/ a 5XRacing kit) in the hope that  it's too much of a coincidence. Maybe the 5XRacing brass cup is warped, one of the shims is crushed, the pivot bushing has crapped out, etc. If that doesn't work maybe the shifter is bent?

 

I just can't believe the same issue (broken 5th gear/reverse) happened on two different transmissions. So if anyone here has run into this problem and has a solution, please post! It would be much appreciated! 

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[Steve Scheifler]

Follow your instinct that it’s not likely a coincidence and first conclusively eliminate things they had in common.
It would be unusual for 5th gear synchro to fail, they are least abused, and it wouldn’t result in the brick wall feel anyway. Were there any chunks in the drain pan when you drained the first one?

I don’t understand why you couldn’t test them outside the car with shifter, it’s not like they have external linkages. But maybe I misunderstood.

Have you removed the boot again and opened the turret to get a better look at what’s happening and try again with it off? Surely that’s the next step, followed by making sure the lever is correctly installed and intact.

Though I doubt it could be hanging low enough or far enough off to cause your problem, did you support the trans to align the PPF per the manual during install? That’s a frequently missed step.

[FTodaro]

Did you pull apart the shifter housing and clean it out or inspect the spring mechanisms that operate the gate on both sides? Did you do it to both, maybe you did not get it back correctly.

[JamesDianto]

Hi guys. Thanks for the replies. When I had both transmission out of the car and on the table I thoroughly cleaned and inspected the shift box, linkages, springs, everything. Cleaned them up really good and greased them up a little before installing. I was careful to make sure I did the "installation is reverse of removal" thing (thanks Miata King!). When they were out, yeah I did use the shifter to test all the gears and they worked. As I mentioned when I put the replacement one in, I was able to get 5th and reverse before bolting the shifter boot down to the turret. It wasn't easy and it felt like I had to move the shifter up a MM to do it. 

 

I just went out to the garage and tested the old one again....and it got stuck! So I took the cap and bolt off (the ones on left side of transmission), and they're fine. I did make sure the shift linkage (the butterfly) was in 5th gear position before I put the rear bolt back in (the one with the spring and ball). Then I cycled the butterfly and now I'm able to get the butterfly into the 5th/reverse positions. 

 

I'm thinking I need to repeat this on the one in the car, see if that works. I'll will give it a shot and see what happens! It just feels like something is physically blocking the shifter from moving to the right (5th/reverse gate) and I'm thinking it's the stupid little ball bearing. A spring by itself can't do that.

 

Oh, and BTW I did the PPF/Transmission alignment thing, using a jack to support the transmission. I was at the track this weekend and it felt good so I'm thinking that's not it. All the other gears work fine. And there wasn't any metal filings in either of the transmissions gear oil when I drained them. 

[Bench Racer]

Did you watch the Miata King video referencing the reverse gear switch which is on the divers side of the transmission?

 

[JamesDianto]

I did! I've seen all of the Miata King's videos! Love 'em! I was thinking of the reverse switch too. I put a brand new one in the transmission I swapped out. Mine isn't stuck in reverse (can't even get to it!) but I'm thinking I'll just pull the switch out, make sure the detent is in the proper position and try to row through the gears, see if that does anything. 

[JamesDianto]

AH HAH! I figured it out! After doing a little more research (actually, connecting the dots from separate posts) I found the culprit was a ball bearing, a spring and a detent cap in the shifter "box" that was keeping the shifter itself from entering the 5th/reverse gate. The original transmission had the issue most likely from the cap either moving out of position OR the ball bearing was getting stuck, keeping me from getting into 5th. Once I had the original transmission on the work table and separated the unit parts I found that I was able to move all the gears into position, so it wasn't the gears, synchros, spacers or rods. So turns out the transmission I pulled was probably just fine!

 

The replacement transmission...that was my fault. I had installed the cap without putting the trans into 5th gear (or reverse) first, which gives the cap/ball/spring enough room to sit perfectly on the detents. Plus I probably hadn't positioned the cap perfectly (the flat end has to be facing the rear of the transmission so the ball can "ride" on it). I pulled that one out with the transmission still in the car, and found that the ball was jammed into the bolt, so that explained that! (see pics). That steel ball bearing usually sits on top of a small spring!. Replaced it and now it works fine...5th and reverse!

 

So if y'all hear of someone with this problem, point 'em to this post!  

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[Bench Racer]

 

The replacement transmission...that was my fault. I had installed the cap without putting the trans into 5th gear (or reverse) first, which gives the cap/ball/spring enough room to sit perfectly on the detents. Plus I probably hadn't positioned the cap perfectly (the flat end has to be facing the rear of the transmission so the ball can "ride" on it). I pulled that one out with the transmission still in the car, and found that the ball was jammed into the bolt, so that explained that! (see pics). That steel ball bearing usually sits on top of a small spring!. Replaced it and now it works fine...5th and reverse!

 

So if y'all hear of someone with this problem, point 'em to this post!  

Miata King Mike's video showing what James explained above.