T56 help - 3rd gear grind
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Joined: May 2006
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T56 help - 3rd gear grind
The car is a 2002 Z06 with 18k miles on it.
We were at the drag strip and suddenly we couldn't easily shift into 3rd gear. It was grinding and not wanting to go in. I could shift very hard and it would go into gear, but not nearly as fast or smooth as normal. Even on the drive back home it wouldn't easily slip into third. This was last spring, and the car has mostly sat due to a shoulder surgery keeping me from fixing it.
My assumption was a synchro ring because it was only affecting third gear, and not fourth. I had thought maybe it was the synchro keys but it wasn't affecting fourth gear.
I now have the transmission fully torn apart on my work bench and other than the small bearing I destroyed when removing it from the main shaft, I can't find anything that seems to be broken or wrong. This has me truly boggled.
We were at the drag strip and suddenly we couldn't easily shift into 3rd gear. It was grinding and not wanting to go in. I could shift very hard and it would go into gear, but not nearly as fast or smooth as normal. Even on the drive back home it wouldn't easily slip into third. This was last spring, and the car has mostly sat due to a shoulder surgery keeping me from fixing it.
My assumption was a synchro ring because it was only affecting third gear, and not fourth. I had thought maybe it was the synchro keys but it wasn't affecting fourth gear.
I now have the transmission fully torn apart on my work bench and other than the small bearing I destroyed when removing it from the main shaft, I can't find anything that seems to be broken or wrong. This has me truly boggled.
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From: Machineguns, because I don’t compromise
Look at the little coffin shaped teeth on 3rd gear. If any of the points are smooshed or sheared that is one point making things harder for the syncro collar to slip past.
Thread Starter
Instructor
Joined: May 2006
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I am also curious as to just how messy the factory was with silicone. I have found what appears to be black silicone in a bearing and in the reverse synchro. The shifter cover plate bolts all had quite a bit of excess silicone on the ends of them when I pulled them out as well.
The car had 8,600 miles on it when I got it 3 years ago, so while I know it's less likely that somebody else has been in there, I do know it's possible something has happened during those 15 years before I owned it.
The car had 8,600 miles on it when I got it 3 years ago, so while I know it's less likely that somebody else has been in there, I do know it's possible something has happened during those 15 years before I owned it.
Thread Starter
Instructor
Joined: May 2006
Posts: 123
Likes: 15
Thread Starter
Instructor
Joined: May 2006
Posts: 123
Likes: 15
Well, in case anyone else has this issue, I think I found the source of the problem. The 3rd gear blocker ring was cracked clean through on one side. I found this post that helped me identify it.
https://www.ls1gto.com/threads/t56-r...sychro.256667/
https://www.ls1gto.com/threads/t56-r...sychro.256667/
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From: Machineguns, because I don’t compromise
I got all my parts from the gearbox.
I needed 2nd gear on mine. It was hammered a little more than your 3rd. That said your third gear isn’t healthy.
Upgraded mine with a stage 2 master rebuild kit (bearings and new syncro assemblies) but didn’t install bronze pads, used new OEM ones.
https://m.thegearbox.org/T56.html
I needed 2nd gear on mine. It was hammered a little more than your 3rd. That said your third gear isn’t healthy.
Upgraded mine with a stage 2 master rebuild kit (bearings and new syncro assemblies) but didn’t install bronze pads, used new OEM ones.
https://m.thegearbox.org/T56.html
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