Transmission problems 6 speed stuck in 4th
Thread Starter
Instructor
Joined: Jan 2012
Posts: 113
Likes: 2
From: Toronto Ontario
Transmission problems 6 speed stuck in 4th
Suddenly today I had the transmission get stuck in 4th gear. I have read up about the issues with alum. forks and syncros, being this is a z06 trans. Is there any way I can get it in neutral? It is stuck in 4th and will not disengage nor move at all. I am figuring it is the above listed issue. Is there any way to disengage the transmission so I can get it to the shop without smoking the clutch in the process?
Any insight would be great.
Any insight would be great.
Racer
Joined: Mar 2013
Posts: 325
Likes: 0
Depending on how far the shop is, it is entirely probable you could make the entire trip in 4th gear. Z06 has the torque to do it, I've done it for giggles.
You're in all likelihood going to have your tranny popped open anyway, depending on your mileage and plans with the car it might be proactive to have the clutch changed while you are in there to begin with. I wouldn't worry too much about a couple of red light starts in 4th. I'd be more worried about Billy Bob Towing getting a low C5 onto a towing bed and off without damage.
You're in all likelihood going to have your tranny popped open anyway, depending on your mileage and plans with the car it might be proactive to have the clutch changed while you are in there to begin with. I wouldn't worry too much about a couple of red light starts in 4th. I'd be more worried about Billy Bob Towing getting a low C5 onto a towing bed and off without damage.
Thread Starter
Instructor
Joined: Jan 2012
Posts: 113
Likes: 2
From: Toronto Ontario
I'm not worried about the motor, it's a 422 stroker. The trans was brand new gm in a crate and probably has less than 5k miles on both trans and dual disk clutch. I am thinking the shifter is locked in gear? It won't pop out or go into neutral either.
Drifting
Joined: Nov 2010
Posts: 1,262
Likes: 70
From: san diego CA
When my oem trans was toast, a similar thing happened to me. It got stuck in either third or fourth while driving to work, and I kinda panicked and kept forcing it really hard until it came out. Not sure if it was the best plan, but I was able to carry on my with my day (just skipping that gear of course). Went on to an RPM built trans and am very pleased
Melting Slicks
Joined: Sep 2011
Posts: 2,258
Likes: 544
From: Appleton WI
I know this sounds too simple but have to ask to eliminate possible sources of your trouble. Have you verified you have sufficient clutch fluid? Open the resevior to look, don't peek through the side.
I had a leaking slave cylinder and didn't realize it. The fluid got low and I could disengage the clutch to stop forward motion but couldn't shift.
I had a leaking slave cylinder and didn't realize it. The fluid got low and I could disengage the clutch to stop forward motion but couldn't shift.
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Pro
Joined: Sep 2012
Posts: 610
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From: Finleyville PA
Mine got stuck in third yesterday. Doing some searches here to see if anyone has an answer. When I replaced the shifter, like you, nothing happened. However, when I started to remove the box underneath the shifter, it came free. I removed the two torx mounting bolts first, as I couldn't get to the one on the shaft since third pushes it back.
Anyway, it seemed to come free when the alignment of the box was changed. Don't know if this could be a reason to cause it to come free or just good luck, but this thing was STUCK in third! It would move just a little but that's it.
Don't know what I'm going to do at this point. Guess I'll drive it, on short trips only, to see what happens.
I'm hearing that the forks could be bent and also read that the aluminum fork should be changed to an iron one.
Keep us posted..
Anyway, it seemed to come free when the alignment of the box was changed. Don't know if this could be a reason to cause it to come free or just good luck, but this thing was STUCK in third! It would move just a little but that's it.
Don't know what I'm going to do at this point. Guess I'll drive it, on short trips only, to see what happens.
I'm hearing that the forks could be bent and also read that the aluminum fork should be changed to an iron one.
Keep us posted..
Last edited by RMB97LS1; Apr 19, 2013 at 09:58 AM.
Pro
Joined: Mar 2010
Posts: 691
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From: Los Angeles
This is pretty common. I've seen it on both my C5 and my brothers T/A tranny. What happens is the 3-4 shift fork is made of aluminum and bends. Once it bends, the tranny will pop out of one gear and sticks in the other. It slides the synchro too far and the synchro key pops out/breaks or the spring binds. Make certain they replace it with a steel fork, billet keys and bronze fork pads are a good upgrade while you're at it...
Burning Brakes
Joined: Feb 2013
Posts: 904
Likes: 296
From: Sacramento, California
My 02Z does get stuck in 4th every once in a while which has me wondering what's going on. My Z has 26k miles and has gotten stuck in 4th about 4 times in the past 2 years. I've noticed it randomly does this on longer road trips of 1 hour or more, but not always. Fortunately I've been able to get it out of 4th each time by applying forward pressure on the shifter while slowly letting the clutch out. If I just try pushing the clutch in and forcing the shifter to N it doesn't budge, but pushing forward while engaging the clutch seems to pop it out. I'm aware of the aluminum 3-4 shift fork weakness, but if the fork was bent wouldn't I have this problem all the time and not just randomly on long road trips? The trans shifts fine during normal around the town driving and short trips.
Steve
Steve
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From: Machineguns, because I don’t compromise
Has 3 stamped metal keys that ride in slots and they act as a detent to help the syncro stay locked on 3rd or 4th.
Whats happened is one of the keys has split and it gets lodged which causes you not able to move the syncro assembly as planned. Moving back and forth on the shifter can jostle the broken key enough to move the syncro but the only fix is to change the split key which means total disassembly. The 3rd/4th syncro is one of the last parts to come off the transmission. Total disassembly.
A common upgrade is to buy aftermarket solid billet keys instead if the cheap stamped ones.
Whats happened is one of the keys has split and it gets lodged which causes you not able to move the syncro assembly as planned. Moving back and forth on the shifter can jostle the broken key enough to move the syncro but the only fix is to change the split key which means total disassembly. The 3rd/4th syncro is one of the last parts to come off the transmission. Total disassembly.
A common upgrade is to buy aftermarket solid billet keys instead if the cheap stamped ones.
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Moved to C5 Tech and this is a 6 year old thread.
6th Gear
Joined: Feb 2020
Posts: 6
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From: Santa Cruz CA
03 Z06 stuck in 4th
Spent the day at the track (Laguna Seca) last Saturday with HOD. All good but when leaving to drive home my '03 ZO6 got stuck in 4th. Limped all the way home to Santa Cruz and after pulling and stopping was able to get it out of 4th and finish the drive home (using only 1-2-3 gears). Today I tried driving again but same thing happened. This time I couldn't get it out of 4th until I turned off the car. Is this the 3-4 synchro key issue I've read about in this forum?
Melting Slicks
Joined: Dec 2018
Posts: 2,667
Likes: 1,394
From: Orange County, CA
Spent the day at the track (Laguna Seca) last Saturday with HOD. All good but when leaving to drive home my '03 ZO6 got stuck in 4th. Limped all the way home to Santa Cruz and after pulling and stopping was able to get it out of 4th and finish the drive home (using only 1-2-3 gears). Today I tried driving again but same thing happened. This time I couldn't get it out of 4th until I turned off the car. Is this the 3-4 synchro key issue I've read about in this forum?
Burning Brakes
Joined: Jan 2021
Posts: 891
Likes: 754
From: SW Desert
Spent the day at the track (Laguna Seca) last Saturday with HOD. All good but when leaving to drive home my '03 ZO6 got stuck in 4th. Limped all the way home to Santa Cruz and after pulling and stopping was able to get it out of 4th and finish the drive home (using only 1-2-3 gears). Today I tried driving again but same thing happened. This time I couldn't get it out of 4th until I turned off the car. Is this the 3-4 synchro key issue I've read about in this forum?