derekkg Posted September 29, 2015 Share Posted September 29, 2015 Hi Everybody, My transmission recently got stuck in 4th gear. It is a 3 piece design, I believe one of the earlier "type a" designs: http://www.zcarz.us/TechnicalInformationPageTransmission.htm I dropped it out of the car this weekend and tore it down. I think I found the source of the problem, but I don't know what the solution is. Any help would be appreciated. I took a video I took talking and showing what I think the problem is: https://drive.google.com/file/d/0B5N_fYOaC113bFZRVDRjN0s4VDA/view?usp=sharing It seems like there might be a few problems. The input shaft with 4th gear on it can slide in and out a few mm, but I think that would be solved when it is back in the case and the c clip is locking the main input bearing in place. The bigger problem seems to be that the coupling sleeve (#10) is going too far forward, allowing the "Shifting insert" (#11) and "Spread spring" (#12) to pop up behind the coupling sleeve and get stuck (See attached diagram). The only way I can get it out of 4th after that happens is to push the 3 shifting inserts down under the coupling sleeve manually, and then pull it back. Does anyone have any idea what could be causing this? Do the shifting inserts need something to keep them from popping out? Or does the sleeve and fork have a mechanism to prevent it from going so far forward that needs to be fixed? It also might be worth mentioning that all of the detent balls and springs are removed. Here is a different video I took showing the stuck inserts as I try to get it out of 4th. https://drive.google.com/file/d/0B5N_fYOaC113b05YUnI5SWlzejA/view?usp=sharing Any help would be appreciated. Thanks! Quote Link to comment Share on other sites More sharing options...
NewZed Posted September 30, 2015 Share Posted September 30, 2015 Would have been informative to see where the inserts are in 3rd gear. Maybe your shift fork is moving the coupling sleeve farther than it should. I've messed with a torn down transmission (didn't put it back together though, it was beyond fixing) and did have to hold those inserts in place to get the sleeve around them so they would pop out if you move the sleeve too far. Check the shift fork's position on the shaft. You might have a broken or missing roll pin. Kind of looks like your shift fork has moved on the rod. If that's not it, there's a Hybridz member, duragg, who has delved deeper in to these transmissions than most. Not the early ones like yours, but I believe the internals are about the same. Might be worth shooting him a PM with a link to your thread to get his attention. He's around, but not recently. Here are a couple of his threads. http://forums.hybridz.org/topic/110792-high-rpm-shifting-dynamics/ http://forums.hybridz.org/topic/109855-green-machine-online-logbook/ Quote Link to comment Share on other sites More sharing options...
derekkg Posted September 30, 2015 Author Share Posted September 30, 2015 https://drive.google.com/file/d/0B5N_fYOaC113MUpsSmExTkY2SlU/view?usp=sharing Here is a video of it in 3rd gear too. I actually managed to get it stuck in 2nd gear too, by pushing the coupling ring into 2nd gear, about halfway out, and then all the way back into gear again. This is interesting. Where is the roll pin? I don't see it in either diagram. I checked the fork on the rod. It seems ok, because when all 3 rods are lined up in neutral, the forks and coupling rings are all in neutral. Is there a better way to check that? Is the fork position on the shifting rod adjustable? Thanks for those links! I also meant to mention that the 3rd gear synchro was nearly non existent when the trans was still shifting, it often would grind when going into 3rd. I wonder if that synchro getting worn down caused the coupling ring to move further than normal Quote Link to comment Share on other sites More sharing options...
NewZed Posted September 30, 2015 Share Posted September 30, 2015 The pin is #15 in your second diagram. Retaining pin. But, checking the center position seems like a good way to check the fork location. Sounds like they're okay. I'm not sure what stops the fork from moving forward though. Maybe that's the problem. 2nd gear might use the same stop as 4th, so that's a sign. Figure out what stops the shift fork travel. Might be the detent balls on the shifting rods. The notch or the ball might be damaged allowing too much travel. They're in the adapter plate (center section) under those bolts. Found a drawing in the FSM that's interesting. Maybe you're missing a "fork rod ring". Don't know what they do but they look like stops for the rod. I've been in to a few transmissions but they're not my forte. Quote Link to comment Share on other sites More sharing options...
derekkg Posted September 30, 2015 Author Share Posted September 30, 2015 Awesome, thanks for the advice. I have the fork ring rods, they are just c clips that stop the rods from going too far backwards, not forwards. I didn't think about that...I pulled the detent balls and pins out when I took it apart, maybe they help. I'll put them back and see if that solves it (although it doesn't explain how it happened in the first place) Quote Link to comment Share on other sites More sharing options...
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