4th Gear grind
Thread Starter
Racer
Joined: Jan 2011
Posts: 301
Likes: 0
From: Canon City Colorado
4th Gear grind
So after two passes at the track last night (1/4 mile) the tranny is now grinding when going into 4th gear. It only does this on higher RPM shifts. It seems to shift into 4th fine when your not on the throttle.
I have done some research and it seems that the syncros might be bad. I have also seen other posts about the shifter not being properly aligned. It currently has a B&M Ripper and seemed to be fine prior to last night. The clutch is an Texralia OZ 700 (4k miles) and seems fine also
The tranny fluid (Amsoil) has just been recently changed so I don't believe that is an issue either.
Any thoughts?
I have done some research and it seems that the syncros might be bad. I have also seen other posts about the shifter not being properly aligned. It currently has a B&M Ripper and seemed to be fine prior to last night. The clutch is an Texralia OZ 700 (4k miles) and seems fine also
The tranny fluid (Amsoil) has just been recently changed so I don't believe that is an issue either.
Any thoughts?
Le Mans Master
Joined: Jul 2010
Posts: 6,007
Likes: 723
So after two passes at the track last night (1/4 mile) the tranny is now grinding when going into 4th gear. It only does this on higher RPM shifts. It seems to shift into 4th fine when your not on the throttle.
I have done some research and it seems that the syncros might be bad. I have also seen other posts about the shifter not being properly aligned. It currently has a B&M Ripper and seemed to be fine prior to last night. The clutch is an Texralia OZ 700 (4k miles) and seems fine also
The tranny fluid (Amsoil) has just been recently changed so I don't believe that is an issue either.
Any thoughts?
I have done some research and it seems that the syncros might be bad. I have also seen other posts about the shifter not being properly aligned. It currently has a B&M Ripper and seemed to be fine prior to last night. The clutch is an Texralia OZ 700 (4k miles) and seems fine also
The tranny fluid (Amsoil) has just been recently changed so I don't believe that is an issue either.
Any thoughts?
Thread Starter
Racer
Joined: Jan 2011
Posts: 301
Likes: 0
From: Canon City Colorado
Le Mans Master
Joined: Dec 2006
Posts: 7,251
Likes: 16
From: Phoenix Arizona
mine does this when fluid is old. sometimes too slippery a fluid does not let your syncros work 
i heard the new gm stuff is really good and i think it is the same as valvoline. i am going to try it next, my 4th gear is starting to grind a bit again
do a search
Premium Supporting Vendor
Joined: Aug 2001
Posts: 5,364
Likes: 38
From: King George VA
Highly doubt it is the fluid, this is probably the most shear stable tranny fluid on the market. I've been using this fluid for years in mine at I shift much more often than at a 1/4 run and have not had any problems.
The Tremec T-56 has many well know problems in this area including both the synchros themselves and the shift forks which can bend, particularly when used hard which may be the case more in 1/4 mile runs than at a road course. A common fix is to go to steel vice aluminum shift forks.
Do a search for bent shift forks.
Another common problem is the clutch slave cylinder which lets air get into the system resulting in poor clutch disengagement. Bleeding the clutch often can help mitigate this, but ultimately, changing the slave cylinder will be required. Note that bleeding the clutch is a major PITA. But, I've done it enough that I now can reach up in front of the tunnel heat shield plate, around the exhaust manifold and get a wrench on the bleed port without having to remove anything. Need small hands...
Good luck!
The Tremec T-56 has many well know problems in this area including both the synchros themselves and the shift forks which can bend, particularly when used hard which may be the case more in 1/4 mile runs than at a road course. A common fix is to go to steel vice aluminum shift forks.
Do a search for bent shift forks.
Another common problem is the clutch slave cylinder which lets air get into the system resulting in poor clutch disengagement. Bleeding the clutch often can help mitigate this, but ultimately, changing the slave cylinder will be required. Note that bleeding the clutch is a major PITA. But, I've done it enough that I now can reach up in front of the tunnel heat shield plate, around the exhaust manifold and get a wrench on the bleed port without having to remove anything. Need small hands...
Good luck!
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Melting Slicks
Joined: Feb 2003
Posts: 2,966
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From: Frederick Maryland
St. Jude Donor '08-'09-'10-'11
If you are having problems shift ONLY into 4th gear at high RPM, then it's NOT the fluid, shifter or clutch hydraulics. If you have shifting problems in all gears, then that would be different. If you are pulling the trans, inspect the 3-4 shift fork pads and 4th gear blocking rings very closely.
I had one with the same symptom a while back and it was a cracked 4th gear blocking ring.
Contrary to popular belief, the shift forks do not bend. The 5-6 and reverse forks are made of steel and 1-2/3-4 forks are made of aluminum (later model C5 units had steel 3-4 fork). I have seen them break but never bent.
I had one with the same symptom a while back and it was a cracked 4th gear blocking ring.
Contrary to popular belief, the shift forks do not bend. The 5-6 and reverse forks are made of steel and 1-2/3-4 forks are made of aluminum (later model C5 units had steel 3-4 fork). I have seen them break but never bent.
Thread Starter
Racer
Joined: Jan 2011
Posts: 301
Likes: 0
From: Canon City Colorado
If you are having problems shift ONLY into 4th gear at high RPM, then it's NOT the fluid, shifter or clutch hydraulics. If you have shifting problems in all gears, then that would be different. If you are pulling the trans, inspect the 3-4 shift fork pads and 4th gear blocking rings very closely.
I had one with the same symptom a while back and it was a cracked 4th gear blocking ring.
Contrary to popular belief, the shift forks do not bend. The 5-6 and reverse forks are made of steel and 1-2/3-4 forks are made of aluminum (later model C5 units had steel 3-4 fork). I have seen them break but never bent.
I had one with the same symptom a while back and it was a cracked 4th gear blocking ring.
Contrary to popular belief, the shift forks do not bend. The 5-6 and reverse forks are made of steel and 1-2/3-4 forks are made of aluminum (later model C5 units had steel 3-4 fork). I have seen them break but never bent.
The car was suppose to have a "Level IV" tranny with only 3k miles since the rebuild. It was done by A One Transmission Performance in Pasadena Maryland by the previous owner. He gave me the invoice that showed that he paid $2300 to have it done.
The invoice is hand written and a little hard to read. But I can make out that is got (4) new sycros and 3-4 steel shift forks. Also something about a 3rd case speed gear.
The car is pushing a lot more power (600+) thanks to the A&A sc and meth. I was hoping it would last longer but no use dwelling on it. I am looking into a RPM level IV or V tranny although I'm not entirley sure yet,
