screeminc5

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.

hamhead

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.

screeminc5

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.

AngryTurtle

Most likely your 4th gear synchro key is broken. Its not an uncommon issue. Just have it put on a flat bed. It will be cheaper then the damage you do to your clutch.

Laser Guided

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

screeminc5

I tried forcing it out of forth but it won't even budge and I have put a lot of pressure short of bending the shifter. Something is locking it in gear.

3sACROWD

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.

screeminc5

I don't have that problem. I can't get the shifter out of forth. It will still release the clutch normally and drive. The issue is the trans won't get out of 4th gear.

IRON MAIDEN

Did you inspect the shifter itself? Maybe something came loose and is binding in there. Just a thought.

screeminc5

I took the whole shifter out and tried both a hurst and b&m ripper

RMB97LS1

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..

screeminc5

I've decided to take it out and do the clutch while I'm there

whitesmokels1

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...

killian96ss

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

~Josh

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.

Vetteman Jack

Moved to C5 Tech and this is a 6 year old thread.

jkevallen

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?

MetalMan2

It sounds like 3-4 shift fork issue (which I suspect is what you meant). Regardless the next step is to tear apart your trans.

ariZona06

Can you go into 5th? I'm currently having a problem with my trans where it grinds going into 4th. The odd thing is if I shift from 3rd to 5th then down to 4th it works fine with no grinding. I'm going to install an original C5 shifter assembly (I do believe I currently have an MTI) but alas I think I'm going to be cracking open the coin purse for a trans rebuild.

jkevallen

Yep, don't think there's an easy way around this. I actually didn't try 5th thinking if it gets stuck there then I'll really have a hard time from a stop. I'll let you know what I find out.